VMS EXCHANGE format for VAX console media
I have a copy of an 11/730 console tape which I have been told is in EXCHANGE format as created by the CONSCOPY utility. Can any of the VMS experts here help this VMS noob learn how to translate that into a raw block-level image of the corresponding TU58 tape, which I might be able to use with a TU58 emulator? I see that the EXCHANGE image is 512 bytes longer than a full TU58 tape. Could it be as simple as chopping off the first or last 512 bytes? I'm not quite at the point yet where I know what a console tape ought to look like in a hex editor, so I can't clearly see whether that might work yet. I'm presently starting to work on getting some version of VMS running on an emulated 11/780 under simh. So with any luck, I may have a functioning VMS environment before too long, even though I haven't managed to boot up my real 11/730 yet. My end goal is to use that console tape image with some TU58 emulator to boot up my real VAX. I have some original console tapes for it, but they no longer seem to be readable. I did get my machine to examine one of them quite a bit before deciding it wasn't suitable, so maybe there is still some recoverable data on those tapes... but none of them seem to be sufficiently error-free to boot my machine. I'm presently working on booting it from a downloaded console tape image, but getting tu58em and my 11/730 to like each other is still an ongoing project. Once I get there, I think that this EXCHANGE format image that I have is the same console tape version as my unreadable real tapes, and newer than the other downloaded image that I'm presently trying to use, so it would be nice to be able to get it into a format that I can use directly. Thanks in advance for any clues! -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: Omnibus pcb layout. Was: pdp8/e /f /m Omnibus legenda available
On Jun 6, 2015, at 07:10, Simon Claessen sim...@dds.nl wrote: Oh and i've made a omnibus pcb layout in Kicad with a corresponding schematic part with all signals. I will put it on our hack42 github account. As i have not mastered the art of making a template, it is a kicad project. VERY cool! -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: pdp8/e /f /m Omnibus legenda available
On Jun 5, 2015, at 14:31 , Simon Claessen sim...@dds.nl wrote: link: https://hack42.nl/wiki/Bestand:Omnibus_legenda.pdf Nice work! -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: Holy mother of pearl. 25000 for an 026
I think I'd enjoy having an 029 if the right one appeared at the right cost and location. But I think I could get by with an 026 for $9! :) I have zero experience with keypunch machines and zero practical use for one... but I think it would be fun anyway. -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: VAX-11/730 %BOOT-F-Unexpected Machine Check
On Jun 8, 2015, at 07:05, Mike Ross tmfdm...@gmail.com wrote: On Mon, Jun 8, 2015 at 7:05 AM, Mark J. Blair n...@nf6x.net wrote: I finally got the excellent AK6DN tu58em emulator working as my VAX-11/730's console drive, as discussed on VCF. Could you throw me a link to that please? I have a 730 I'm going to have to have a hack at at some point... Sure! I'll take this opportunity to document a lot of the different pieces that I had to dig up to get this all working. First, here is Don AK6DN's TU58 emulator: https://www.ak6dn.dyndns.org/PDP-11/TU58/tu58em/ It's a DEC computer life-saver! I started with v1.4j, and modified it to 1) build on my Mac and 2) remove some delays that caused trouble with the console firmware's very aggressive 20ms IDLE-IDLE to CONTINUE turnaround timeout. Don hasn't had a VAX 725/730/750 to test it against, and it turns out that the 730 didn't like it at first. I've shared my fork here: https://github.com/NF6X/tu58em Note that the master branch, which comes up by default, is Don's original tu58em code. My changes are on the nf6x branch. I believe that Don plans to update his original code based on this experience, but I don't know yet whether he will do it the same way that I did or take a different approach. Both his original code and my fork are likely to change by the time you get back to your 730. :) I got my console tape images here: http://www.heeltoe.com/download/vax/tapes-730/README.html I also put a copy of those images on my GitHub account, along with some other bits such as the extracted files from them: https://github.com/NF6X/VAX-11-730-Console-v57 I have an RL02 pack of the Customer-Runnable Diagnostics that came with my system, and appears to be compatible with the CRD tape in that set of console tape images. I don't have a way to image it yet, but when I do I will add the image to that repository along with the console tape images. In working with the images, I learned that the console boot tapes are in RT11 format, but they don't strictly adhere to the RT11 filesystem documentation. They have, variously, spaces or NULs in place of some key fields such as the first directory segment entry of the header block. That was causing my RT11 filesystem utility to blow chunks on them, so I added a hack to it so it can read them now: https://github.com/NF6X/pyRT11 I have not yet tried to boot my VAX with a console tape image that has been generated with my pyRT11 code, so I don't know yet whether they will like each other. I figure I may need to experiment with that at some point, for example to change the DEFBOO.CMD as appropriate for my system. I found some VAX-11/750 console tape images plus a bunch of other TU58 images here: http://iamvirtual.ca/VAX11/VAX-11-software.html Since I can't seem to boot up my R80 or my other RL02 pack (labeled VMS53RL02SYS on top) yet, I've been trying to bring up the VMS 5.3 Standalone Backup tape images I found there. No luck so far. I have never run a VMS Standalone Backup environment before, but I am blindly hoping that it will be a small VMS environment that will let me try to mount filesystems from my hard drives and see what, if anything, is on them. I would greatly appreciate any clues here, because I'm in unknown waters. If anybody has relevant TU58 images that aren't already archived at one of the sites above, PLEASE share them and/or point me to where they are! And please make sure they get archived! -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Pertec Tape Drive Interface Musings
I was looking at a couple of documents describing the Pertec tape interface; the manual for my Kennedy 9610 tape drive, and a nice reference by a fellow with a rather familiar name: http://www.sydex.com/pertec.html According to my Kennedy manual, issuing a read command causes the drive to return one block of data. I can see how that would be used in block-oriented applications in which blocks may be randomly read, written and re-written on the tape. But most of my magtape experience has been using the tapes in a streaming mode, such as when reading/writing one or more tar archives separated by file marks. When writing a tar archive on a magtape from a Unix system, is the archive written as a sequence of fixed-size blocks? Or is the entire tar archive effectively written as one continuous block which must be streamed with no repositioning? I'm curious because I'm daydreaming about how to build a tape drive interface controller, and I wonder whether it might need to potentially stream an entire tape in one go vs. being able to safely assume some maximal block size. -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: Blue tape retainers
On Jun 9, 2015, at 15:33 , Chuck Guzis ccl...@sydex.com wrote: Could this be the right stuff? http://www.amazon.com/Grafix-9-Inch-12-Inch-9-Pack-Assorted/dp/B00114OVFE/ref=pd_sxp_f_pt It seems to me that I've seen it in the form of letters to be stuck to windows. That looks really promising. It would probably be easy to slice into neat strips with one of those circular-blad paper cutters from the local office supply store. -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: WTB /WTT DEC TZ30 and/or 1/2 open reel SCSI magtape drives
On Jun 9, 2015, at 15:44 , Glen Slick glen.sl...@gmail.com wrote: An alternative would be to look for a cheap Fujitsu M2444AC tape drive (often seen with Sun badges). They have Pertec interfaces, but it is probably easier and cheaper most of the time to find a Pertec tape drive interface for a DEC system than a SCSI interface, and they can be interfaced to ISA bus PCs. They are built like tanks and weigh around 200 pounds, which is why they can sometimes be had for cheap if you find one within driving distance because no one would want to pay to ship one. I'm looking for a SCSI interfaced drive so I can hook it up to my Sun Ultra 60, running Solaris 8. I don't run any ISA bus machines other than a 5155 Portable PC and a very crappy old 386 box dedicated to running ImageDisk, and my Sun would be much easier to use for this purpose, I think. It's also just new enough that it's not hard to get it talking to my current machines over the network, so it makes a nice bridge machine. I already have a magtape drive on my VAX, and was pleased to see it pass the diagnostic tests this weekend. It's a TU80. It hooks up to my VAX with a couple of 50-pin connectors... Hmm, maybe it has a Pertec interface, so another option might be to find a Pertec to SCSI adapter and use the same drive on multiple systems? I also already have a front-loading Kennedy drive with a Pertec interface which is earmarked for use on my future PDP-11/44 project. It needs some work, as it lost hub drive in one direction shortly after I got it. Once I repair it, using it with a SCSI to Pertec adapter would also eliminate the need to shipping yet another magtape drive around. So based on your comments, let me amend my request to say that I would also consider some sort of SCSI to Pertec interface. Thanks! P.S.: For those of you who don't mind clicking on a Twitter link, here's a picture of my VAX system as I was working on it this weekend, shortly before I took a break to let the room cool back down: https://twitter.com/nf6x/status/607650728459407360 The MacBook on top of the VAX is running tu58em. The Ultra 60 is sitting on the floor in front of the TU80 after a previous dead-end attempt to get tu58em running on it, before I figured out how to fix the issue I was having running it on my Mac. The two VAX cabinets are bracketed by my PDP-11/03 on the left, and my Nova 3 on the right. The DECwriter III is working nicely as the VAX console terminal. Oh, and my PDP-8M is sitting on top of the PDP-11/03 rack waiting for its next turn on the workbench. Photobombing the picture from the right is my IBM Mag Card II typewriter, also waiting for restoration. -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: WTB /WTT DEC TZ30 and/or 1/2 open reel SCSI magtape drives
On Jun 9, 2015, at 15:44 , Glen Slick glen.sl...@gmail.com wrote: You don't do eBay any more, and asking over $300 is way to much, but here is what the look like for reference: http://www.ebay.com/itm/191583247197 I have picked up a couple in the $50-$100 range. If their prices weren't so high, I have a friend in Santa Paula who might be able to help picking up something from them in Ventura and stashing it until next time we find ourselves in the same place. -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: WTB /WTT DEC TZ30 and/or 1/2 open reel SCSI magtape drives
On Jun 9, 2015, at 22:11 , Chuck Guzis ccl...@sydex.com wrote: Not complete off-topic, but I just received an email from Shaun Halstead that he's looking to get rid of a CDC Keystone drive (vertically mounted) (read: TU80 family, with Pertec interface) that was apparently used on a Xerox system. If you're in the Chicago area and interested, you might want to drop Shaun a line at microf...@microfilm.kscoxmail.com I'm in southern California myself, but hopefully somebody else here will have a good home for it. I did a Craigslist search for tape drives earlier today, and found a Kennedy 9100 with SCSI interface in the Phoenix, AZ area. Probably a bit too far for me. But it looks cool: Seems to be the same mechanism as my TU80, right down to the membrane keypad, but in vertical orientation. Any particular reason why Pertec IF isn't desirable? I already have 1-2 Pertec IF drives; my Kennedy 9610, and presumably my TU80 based on the two 50-pin cables between it and my VAX. I don't have any Pertec interface controllers on my modernish, up-and-running computers, but I do have a fully-working Sun Ultra 60 with SCSI interface, software support for SCSI tape drives, and capable of talking to my NAS for easy file transfer to my main computer (Mac Pro trashcan). I already have two Pertec-capable projects, and I'm looking for something to help me bootstrap those rather than a third similar project. So either getting a SCSI magtape drive or a SCSI to Pertec bridge should get me there more easily. I'm coding now for a Pertec-to-USB interface board. How's that for an anachronism? It's delightful for one, that's how! Think you might make more than one of them, or share the plans? It sounds like something I could potentially use! I've considered making something like that myself, but I have so many such ideas that I am happy to let other folks make some of them for me. :) -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: WTB /WTT DEC TZ30 and/or 1/2 open reel SCSI magtape drives
Oh, and furthermore, I'm much more comfortable in a UNIX environment than anything PC/DOS/Windows. Linux is fine, but I would expect pain getting drivers for some random Pertec card. So, PC platforms that might accept a Pertec card aren't my preferred environment. -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: Blue tape retainers
On Jun 9, 2015, at 22:20 , Chuck Guzis ccl...@sydex.com wrote: On 06/09/2015 09:57 PM, Mark J. Blair wrote: Please forgive my ignorance, but which variety are the Wright Line seals? I think I've encountered three styles of magtape widgets: The common white plastic with a black buckle and squarish hook, which have been on the vast majority of tapes I've ever handled or seen; That one. 3M also had their own variety of seals. Hmm, the NOS 3M 777 tapes that I got off eBay have that one seals. Did 3M later switch to Wright Line seals? Off to google pictures of random mag taps for edutainment purposes... Boy, do I know how to have fun! -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: Blue tape retainers
On Jun 9, 2015, at 22:57 , Chuck Guzis ccl...@sydex.com wrote: The 3M ones that I've seen are hard white plastic (not PVC or whatever Wright Line used) with a keyhole-sort of affair that allows the circle to expand. Interesting. I don't think I've encountered that style before, or if I did, that memory has snuck away in the night. -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: WTB /WTT DEC TZ30 and/or 1/2 open reel SCSI magtape drives
On Jun 9, 2015, at 20:45 , Bob Rosenbloom boba...@sbcglobal.net wrote: I have a Fujitsu M2444AC sitting in my hangar up here in Santa Cruz. You can have it if you can get someone to pick it up. Photo's here: http://www.dvq.com/Fujitsu/ You probably guessed already that my friend in Santa Paula is also a pilot! ;) Thank you very much for the offer! If I'm not mistaken, that drive has a Pertec interface, though, like the Kennedy 9610 that I already have, so I think I will let somebody else have a crack at it. That drive model looks familiar; we probably had at least one in the computer room I worked in during college in the late 1980s, and I may have done a tape mount or two on them! Hmm, I guess I have yet another option: Once I fix the hub motor drive in my Kennedy 9610, maybe I could just make my own interface for it. Maybe a small FPGA to handle the interface signals, and an off the shelf microcontroller (like a BeagleBone Black board?) to give it a UI and interface it to the outside world. Much more effort, but also more fun! I may be able to borrow a SCSI-interface magtape drive locally, but I still wouldn't mind having one of my own. And I am still hoping to find a TZ30 drive. -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
VAX-11/730 %BOOT-F-Unexpected Machine Check
I finally got the excellent AK6DN tu58em emulator working as my VAX-11/730's console drive, as discussed on VCF. The trouble appears to have been a simple timing issue: tu58em includes some time delays which run afoul of the 730 console's very aggressive timeout checking. After patching in a command line flag to disable them, my 730 console seems to be happy with tu58em running on my MacBook Air over an FTDI USB/RS-232 converter. I've also tweaked the FTDI's driver settings to make sure that latency is minimized, but I'm not sure if I changed it significantly from the default. But the console appears to time out if the tape drive takes 20ms or more to respond to the initialization sequence, so every millisecond might impact reliability. With the console working and loading up a version 57 11/730 console tape image that I found online, I've been trying to boot the machine up. When I try to boot from either the R80 or RL02, I get error message %BOOT-F-Unexpected Machine Check. Does that error message mean anything to the VAX experts out there? This machine was believe to be working before time + transport, and I'm trying to bring it up for the first time since I got it. I still have a lot of learning curve to climb, but I'm excited to have made more progress. -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: VAX-11/730 %BOOT-F-Unexpected Machine Check
A couple of folks have clued me in to my mistake: I should have been trying to boot DQ0/1 instead of DU0/1. Now I'm getting disk activity followed by %BOOT-F-Unable to locate BOOT file, which is better! I found 725/730 diagnostics on another tape image, so I'll try running those next. Yay! -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: Holy mother of pearl. 25000 for an 026
On Jun 6, 2015, at 10:28, William Donzelli wdonze...@gmail.com wrote: The main IBM keypunches (026, 029, and 129) are sort of like Teletypes - yes, they have respectable value, but there are still a whole lot of chances to get into a right place, right time situation and get them for nothing. At this point, I have started to pass them by, unless it they are super easy to get. Please let me know if you find out about one near me that you don't wish to grab yourself on one of your trips. I'll be happy to do likewise for big stuff that I don't want myself. I figure that for large items like these, the bidding results will depend on whether there are two potential buyers close enough to pick up the item. End result might be no bids, one minimum bid, or a thousand+ bucks, depending. -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: OT: learner kits (was: Re: using new technology on old machines)
On Jun 19, 2015, at 19:19 , Tapley, Mark mtap...@swri.edu wrote: He has a Raspberry Pi, which he pretty much contempts in favor of his laptop, which will play the modern version of MineCraft :-P, but presumably hooking those together might be fun. I suspect that boards like the Raspberry Pi, Arduino, etc. might get a lot more interesting if they can affect the real world. See if a servo motor adds some appeal. -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: Looking for info on National Semiconductor RAM board (VAX 11/730)
On Jun 20, 2015, at 07:58, tony duell a...@p850ug1.demon.co.uk wrote: Oh, and it mentions a 'spare RAM chip in a socket on the board'. All RAM on my board is, indeed, socketed. If this is just an unused chip to substitute if one fails then I think I've seen it all... I thought of throwing that idea out there, but having lived through the great RAM famine the thought of a spare RAM chip seemed kind of silly. Incidentally, the RAMs are all soldered on my Camintonn boards. -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: organizing a trip to Cuba
Oh, I want the whole computer, not just the CPU chip. -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: Pertec Tape Drive Interface Musings
On Jun 10, 2015, at 08:46, Al Kossow a...@bitsavers.org wrote: On 6/10/15 8:15 AM, Mark J. Blair wrote: And that is precisely why I'm thinking of an ad-hoc interface rather than just plugging a SCSI drive into a UNIX box. It also has the advantage that you can return the CRC/checksum and partially read blocks. Most SCSI tape drives don't return the data if the read doesn't succeed. I particularly like the idea of being able to extract questionable data and CRC/checksum. Ok, now three more questions come to mind: 1) Is it ever acceptable to mix densities on a single tape? I'm not sure that my Kennedy drive will even allow that, but I don't know if that is universal. 2) What's the scoop on a final record overlapping the EOT marker? Or even a new record starting after the EOT marker? I seem to recall reading about some applications that stuck data after the EOT, such as backup volume information. 3) Did anybody ever go over to the dark side and implement copy protection on magtapes, say, by deliberately including a record with bad CRC that a normal driver+drive would not support writing? Or was that evil limited to the floppy disk world? -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: WTB /WTT DEC TZ30 and/or 1/2 open reel SCSI magtape drives
Update: TZ30 located and ordered. And now I'm thinking that I ought to build a custom Pertec interface (as is being discussed in another thread) that's particularly suited for archival work, though I might still be interested in a SCSI magtape drive or SCSI/Pertec adapter anyway. -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: using new technology on old machines. Was: PDP-12 Restoration at the RICM
On Jun 16, 2015, at 06:46, tony duell a...@p850ug1.demon.co.uk wrote: Again, I wonder if the data retention time decreases as the number of bits per device increases. Intuitively it should. Mind you, any SD card is probably going to be more reliable than a real TU58 tape now :-) I think that paper tape, used outdoors on a rainy day, is likely to be more reliable than a real TU58 tape. :) -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: PDP-12 Restoration at the RICM
On Jun 14, 2015, at 06:53, Michael Thompson michael.99.thomp...@gmail.com wrote: Dave Tumey sent us a new rubber hammer for the Teletype. This is the part that pushes the print drum against the ribbon and paper to print. These are newly molded parts that have not been available for decades. Works very nicely. I should order one, too. I'm presently using the rubber tubing over the hammer kludge. The donor dropped off the work table that goes in front of the PDP-12. We need to loosen the rusted feet so it will fit under the front panel. That sounds like a good excuse for more pictures! -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: SS10 console settings
On Jun 14, 2015, at 01:49, Mike Ross tmfdm...@gmail.com wrote: I have *only* the serial console. No working keyboard/mouse/screen. If all else fails, do you have the means to look at the serial line with an oscilloscope? Figuring out the port parameters that way might be easier than trying every combination of baud, word length, parity, etc. -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: using new technology on old machines. Was: PDP-12 Restoration at the RICM
On Jun 16, 2015, at 07:36, Chris Elmquist chr...@pobox.com wrote: So, now you have to use a Type A to Type A cable to connect this box to your computer. That is just really, really messed up and I honestly tried to make it right but it was like pushing a rope. I hope my friends will visit me in prison. Sounds to me like you are more of a victim than a perpetrator here. Isn't there some OSHA regulation against USB A to A cables? :) -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
On the Emulation of TU58s
As long as we're talking philosophy, what do y'all think about emulating the TU58 drive, vs. emulating the TU58 *tape*? I cannot properly express my opinion of that tape cartridge design even if I violate list rules about use of profanity. But the drive itself isn't all that bad, aside from not having enough motors to manipulate a well-designed tape cartridge mechanism. Emulating the whole tape drive is pretty easy since it helpfully interfaces over a plain old asynchronous serial port. But replacing the whole drive with an emulator, or worse yet tethering its computer to a modern computer, leaves a bit of an empty feeling if one likes their vintage machines to be original. There's something missing when you don't hear the drive whirring, and the system boot completes within a modern attention span. But what about emulating the tape cartridge, instead? Imagine a gizmo in the form factor of a TU58 cartridge, containing a wheel for the capstan roller to engage, but connected to an encoder instead of the *** * ** belt drive of an original cartridge? Where the tape would normally be exposed, there is instead a magnetic head which rests against the tape drive head like in one of those gizmos for injecting line level audio into an audio cassette drive. It might need an external power source, but for the sake of argument, let's pretend that a suitable rechargeable battery can be embedded. Maybe it has an SD card slot on the rear, or maybe it looks just like a real TU58 cartridge when inserted, and you swap the whole thing to change tapes (this is open for discussion). Would this be more or less acceptable in terms of keeping the system as close to original as possible, vs. unplugging the original drive and plugging in a drive emulator? No, I'm not going to build the thing. I'll just build my TU58 drive emulator to fit in the cartridge slot but plug into the computer in place of the original drive, with the cables snaked through the original drive mechanism. And I'll feel a little bit dirty, but the thing will work reliably and will be easy to implement. I'm just curious about the philosophical implications of my silly cartridge emulator idea. -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: using new technology on old machines
On Jun 16, 2015, at 08:19, geneb ge...@deltasoft.com wrote: On Tue, 16 Jun 2015, Noel Chiappa wrote: I wish there was some _easy_ way to lay in a stock of the most common TTL IC's - e.g. some kind of kit one could buy - but alas, I don't know of any. (Hence my dream of finding and acquiring someone else's collection! :-) Suggestions for the source of such a good diversified 'starter kit' welcome... How about this: http://www.jameco.com/webapp/wcs/stores/servlet/Product_10001_10001_84961_-1 Very nice! I might just order one of those. -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: VAX 11/730
If you can find one, I'll be happy to help out with tape images and so forth for your bringup! On Jun 15, 2015, at 08:32, emanuel stiebler e...@e-bbes.com wrote: As usual, a long shot, but anybody in the list like to get rid of one? Preferably Colorado ;-)
Re: Serial UNIBUS Repeater?
On Jun 15, 2015, at 09:02, Guy Sotomayor g...@shiresoft.com wrote: I'm not specifically familiar with the 11/730, but what's wrong with just cabling up an expansion box the old fashioned way using BC11A cable? Without losing anything else in the already-full rack, I'd need to route that cable between two racks. It's already tricky to roll the cabinets back into place without rolling over the existing round snakes between the cabinets, and I figure that wide ribbon cables would be more cumbersome (or is the BC11A round?). I have the system in a tiny room where it's not practical to have space behind the racks to get rear access without rolling them. -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: Serial UNIBUS Repeater?
On Jun 15, 2015, at 09:06, Paul Anderson used...@gmail.com wrote: Hi Mark, Do you just need a 4 or 9 slot backplane? I Don't see the need for a repeater unless I'm missing something. An expansion without a reapeater would work just fine electrically. I'm curious about whether some sort of repeater exists that uses a thin, round cable for an application where it's desirable to be able to move the expansion around easily. And also where it's cheap and easy to replace the cable after rolling a rack cabinet over it one time too many! :) -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: On the Emulation of TU58s
On Jun 16, 2015, at 09:10 , tony duell a...@p850ug1.demon.co.uk wrote: You would, of course, not know which track it was reading, so you would have to output 2 blocks, one on each track, at once. And how would you detect it was writing? Look for an extra signal at the coupling head or something? That seems to me like it would be the trickiest part. The TU58 schematic appears to indicate that there are separate erase head gaps (not on a separate head like in audio cassette drives), so maybe those could be monitored to detect when a track is being written? Of course, that probably means that a custom 4-gap head would need to be made with gaps matching the two read/write and two erase gaps (and a concave surface, too, rather than recycling some audio tape head with suitable geometry to line up with just the read/write gaps. -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: On the Emulation of TU58s
On Jun 16, 2015, at 11:22 , Johnny Billquist b...@update.uu.se wrote: Pretty much the standard CDC vacuum-column design since the 1960s. The TU80 is, after all, a CDC product. Two counter-rotating capstans--tape movement is determined by applying positive or negative pressure to ether or both (i.e. positive pressure on both results in the tape floating Uh... The TU80/TU81 do not have vacuum columns... Or rotating capstans... -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: On the Emulation of TU58s
On Jun 16, 2015, at 09:10 , tony duell a...@p850ug1.demon.co.uk wrote: Incidentally, given the fact that a constant motor speed - constant tape speed, it should be possible to make a device to put the timing track on a blank tape for the TU58. Has anyone done that? There's no timing track in the TU58 scheme, but there are magnetic BOT and EOT markers that have to be written so that the drive can identify the tape ends. I assume there are also block headers much like on most floppy disks, but I haven't gotten that deep into the formatting yet. The tape includes the BOT and EOT sensing punched holes, and the cartridge includes the angled mirror behind the tape to allow the holes to be sensed with a right-angled optical path. But the TU58-XA drive mechanism does not include the optical sensor that would be needed to sense tape ends on an unformatted tape. I don't know if this was meant as a way to further cost-reduce the already mechanically simple tape drive mechanism, or if DEC did that deliberately to make sure that non-DEC DC100/DC150 cartridges could not be be formatted in the field, so that users would be stuck buying preformatted cartridges from DEC. If new cartridges with brand new, un-decayed belts could be manufactured, then it should be possible to hack up a TU58-XA mechanism for formatting them. I think there may be a little hole in the plastic casting of the drive where one of the optical sensors might be glued in place, if I recall correctly. Oh yeah, the metal vs. plastic base cartridges were also mentioned in this thread. I've only encountered the metal ones so far. Based on the manual pictures, I think the plastic ones use a shorter belt with a simpler path. -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: On the Emulation of TU58s
On Jun 16, 2015, at 12:46 , tony duell a...@p850ug1.demon.co.uk wrote: For something even madder, look at the design of the original Radio Shack 'Line Printer' which was actually a Centronics something-pr-other (733?). This thing (which is not a line printer at all) has a belt running across the chassis with a motor continuously driving it (a shaded pole motor I think). Solenoids on the printhead carriage grab the top or bottom run of the belt depending on which way the carriage is to move. Is that the same screwball printer that has a metal platen spinning behind the paper with horizontal raised lines on it, and a single vertical striker in the printhead that strikes at the moment when the platen and striker intersect at the desired X/Y location of the dot to be printed? I've considered buying one just to hear what it sounds like. -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: using new technology on old machines
On Jun 16, 2015, at 17:52 , Mike Ross tmfdm...@gmail.com wrote: 'remanufacturing' has become part of preservation movements in general; [...] Has this ever been seriously considered, or mooted as a possible co-operative venture for a group of us? On this topic, I'm particularly curious about remanufacturing of consumables such as magnetic media, printer ribbons, etc. Not only are supplies of unused consumables monotonically decreasing, but even remaining ones are succumbing to shelf rot (case in point: TU58 cartridges, and particularly their drive belts). In many cases, it may not be strictly necessary to manufacture the entire item. For a TU58 cartridge, the baseplate, case, reels, etc. may be quite usable. The tape probably needs to be replaced, but maybe a particular formulation of common audio tape could be used instead of manufacturing tape from scratch. The belts would certainly need to be manufactured from scratch. In other cases, even where the item needs to be manufactured from scratch, might it be acceptable to use modern methods to manufacture authentic-ish replacement consumables? If somebody figured out how to create suitable magnetic material and binder for floppy disk media and apply it to mylar sheets, for example, maybe a laser cutter could be used to cut out various kinds of blanks (5.25, 8, soft-sectored, various hard-sectored configurations) without the tooling cost of punching dies that would make more sense for mass production? Would the mentioned automatic wire-wrapping machine need to be recreated in a period-correct manner, or would it be acceptable to make one using modern expedient hardware in order to use it to create new authentic reproductions? What sort of concessions could we accept for the lack of authentic components to be used? In the case of a locomotive, there are an awful lots of parts that could be authentically remanufactured in a regular machine shop (obviously, large forgings and the like would be more challenging!). But in the case of a computer using particular no-longer-manufactured semiconductor components, the thought of bringing up a suitable semiconductor fab to build those components would be economically unrealistic. -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: First VAX-11/730 VMS Boot! (was: Re: VAX-11/730 %BOOT-F-Unexpected Machine Check)
I'm still fumbling around with the multi-tape backup of the R80 drive and haven't quite gotten it working yet. But I've made some other good progress! That RL02 pack labeled VMS53RL02SYS does contain a working VMS 5.3 installation. I backed it up to tape while booted from the R80, then did a conversational boot on it to reset the SYSTEM password. Now I boot from that pack while trying to get the backup of the R80 drive working, so I can have the R80 drive mounted read-only. I also ran off recursive directory listings of both drives while logging in my terminal emulator, so I can go through them later to see if anything interesting is in there. -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: First VAX-11/730 VMS Boot! (was: Re: VAX-11/730 %BOOT-F-Unexpected Machine Check)
Thanks! I will try that out. On Jun 13, 2015, at 18:01, Glen Slick glen.sl...@gmail.com wrote: On Sat, Jun 13, 2015 at 5:45 PM, Mark J. Blair n...@nf6x.net wrote: Thanks, I will read that. But how do I enter the reply command when the BACKUP program is hogging the console? Is there a VMS equivalent to the way a task can be suspended in UNIX with ^Z? I'm no expert, but I think you can sometimes do ^Y, and then CONTINUE, but only if you only execute built-in commands between the ^Y and the CONTINUE.
Re: First VAX-11/730 VMS Boot! (was: Re: VAX-11/730 %BOOT-F-Unexpected Machine Check)
Thanks! I'll look up all of those commands to understand them better. ^Y looks familiar. I think this is the second time I have learned about it. :) On Jun 13, 2015, at 18:40, Jerry Weiss j...@ieee.org wrote: If you are running backup and it is asking for additional tapes, then I believe you can do the following ^Y $spawn $ $reply/enable=all initialize additional tapes as needed (prior tape should have rewound…) mount tape $reply/to=MESSAGEID $exit $continue Jerry Weiss WB9MRI j...@ieee.org On Jun 13, 2015, at 8:04 PM, Mark J. Blair n...@nf6x.net wrote: Thanks! I will try that out. On Jun 13, 2015, at 18:01, Glen Slick glen.sl...@gmail.com wrote: On Sat, Jun 13, 2015 at 5:45 PM, Mark J. Blair n...@nf6x.net wrote: Thanks, I will read that. But how do I enter the reply command when the BACKUP program is hogging the console? Is there a VMS equivalent to the way a task can be suspended in UNIX with ^Z? I'm no expert, but I think you can sometimes do ^Y, and then CONTINUE, but only if you only execute built-in commands between the ^Y and the CONTINUE.
Re: SIO2SD for Atari 8-bits - Just got one.
On Jun 13, 2015, at 16:28, Terry Stewart te...@webweavers.co.nz wrote: I'm in awe of people who can build and design these devices http://www.classic-computers.org.nz/blog/2015-06-13-sio2sd-for-atari.htm Terry (Tez) It looks really slick. I wish Lotharek would make a UNIBUS2SD! :) -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: SIO2SD for Atari 8-bits - Just got one.
I have one of his regular floppy disk emulators. I haven't actually used it yet, but it is put together very nicely. When I get around to trying out the Atari 8 bit world for the first time, I guess I will need an SIO2SD. I gather that those are must-haves, much like the CFFA3000 is for the Apple II. On Jun 13, 2015, at 20:45, Terry Stewart te...@webweavers.co.nz wrote: That is neat where can we get one!? You can order there here: http://lotharek.pl/product.php?pid=63 Terry (Tez) On Sun, Jun 14, 2015 at 2:54 PM, couryho...@aol.com wrote: that is neat where can we get one!? In a message dated 6/13/2015 4:28:28 P.M. US Mountain Standard Time, te...@webweavers.co.nz writes: I'm in awe of people who can build and design these devices http://www.classic-computers.org.nz/blog/2015-06-13-sio2sd-for-atari.htm Terry (Tez)
Re: First VAX-11/730 VMS Boot! (was: Re: VAX-11/730 %BOOT-F-Unexpected Machine Check)
I don't remember exactly what I have, but the binders that came with my system might include an R80 manual (to be scanned, of course!). -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: First VAX-11/730 VMS Boot! (was: Re: VAX-11/730 %BOOT-F-Unexpected Machine Check)
On Jun 14, 2015, at 02:36, Peter Coghlan cct...@beyondthepale.ie wrote: Another way is to log on a second time using a terminal other than the console, issue reply/enable and then reply to the messages you receive there. I'll eventually hook up more serial lines, but at the moment the room is cluttered enough that pulling out the rack will be frustrating. Yet another way is to use BACKUP /NOASSIST - this should avoid issueing OPCOM messages and prompt the issuer of the BACKUP command directly when tapes are to be changed and so on. That sounds like what I want! It's running now. The standard way of doing backups on VMS is to submit a BACKUP command in a batch job. The operator would normally be logged in interactively and would respond to the OPCOM messages from the batch job and deal with tape mounts. This requires a suitable batch queue to be set up and started. I bet that's how I used to run backups as a student computer operator in the late 1980s. But I probably had no understanding of the DCL script I presumably ran. -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: First VAX-11/730 VMS Boot! (was: Re: VAX-11/730 %BOOT-F-Unexpected Machine Check)
On Jun 14, 2015, at 10:01, tony duell a...@p850ug1.demon.co.uk wrote: If the connector on the DELUA board is a normal Berg-type header (and I think it is) then maybe you could use a piece of (twist-n-flat?) ribbon cable to make an extension that could be routed through the cable pan arrangement and then connected to the original DELUA cable back in the rack cabinet. That might be a good approach. The DELUA end of the cable has a Berg connector, and the other end has the typical 15-pin D-sub AUI connector with a slide latch. I'll look up the cable wiring to see if signals that would best be twisted pairs are conveniently placed on adjacent odd/even pins, such that twisted pair ribbon cable would work well electrically. Or maybe I can use the round cable that I already have, with P-shaped cable clamps screwed down using the screws at one end of the flat cable clamps. There may not be enough clearance in the tray for that. -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: Windows and devices - was Re: using new technology on old machines. Was: PDP-12 Restoration at the RICM
On Jun 17, 2015, at 10:50 , Toby Thain t...@telegraphics.com.au wrote: Here's a cute gotcha I hit this week: - Have a running Windows 8.1 machine with PS/2 keyboard. - Shut it down, start up with only USB keyboard. - Shut down and boot again with PS/2 keyboard atached. - Windows ignores it (although BIOS flashes lights normally, etc). - Registry change (found by google) reboot brings it back to life. Can't imagine how many good keyboards were dumpster'd over that one. Working in the GPS industry, I became all too familiar with how Windows can't tell the difference between a Microsoft Serial BallPoint and a 4800 baud NMEA stream. -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: Documation card readers for sale
On Jun 17, 2015, at 16:14 , John Ball ball.of.j...@gmail.com wrote: About six months ago I struck a deal with a place down in California for four Documation M1000's that I've been able to tell so far they all work but I really don't have space for more than one. I've been trying to sell them at a loss for months now over on the Vintage Computer Forums and Nekochan (if you got here you'll find pictures) but no bites. I swear there were people out there that were looking. Where did you folks go? Might anyone here be interested? I absolutely refuse to put them on the curb. Where are they located? I'm known for my poor self-control when it comes to acquiring vintage computer gear, but shipping one of those heavy beasts to southern California might be more than I'd like to spend. :/ -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: Documation card readers for sale
On Jun 17, 2015, at 19:48, Chris Osborn fozzt...@fozztexx.com wrote: On Jun 17, 2015, at 7:43 PM, Mark J. Blair n...@nf6x.net wrote: Are the readers in question these ones in Canada? When you drive up there to get them, you can stop by my house on your way home and drop one off. I’m in Sacramento so I’m right on the way. I’ll let you play some air hockey while you’re here! :-P I sincerely thank you for the offer, but I won't be driving up there. I don't like driving long distances (despite commuting about 20,000 miles per year), and I don't particularly like traveling in general, either. Nope, I'm totally a stay-near-home type, with my one concession being a drive up to San Luis Obispo once a year for a military radio collectors meeting and one or more steaks at Jocko's. -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: Documation card readers for sale
On Jun 17, 2015, at 16:14, John Ball ball.of.j...@gmail.com wrote: About six months ago I struck a deal with a place down in California for four Documation M1000's that I've been able to tell so far they all work but I really don't have space for more than one. I've been trying to sell them at a loss for months now over on the Vintage Computer Forums and Nekochan (if you got here you'll find pictures) but no bites. I swear there were people out there that were looking. Where did you folks go? Might anyone here be interested? I absolutely refuse to put them on the curb. Are the readers in question these ones in Canada? http://www.vintage-computer.com/vcforum/showthread.php?45888-FS-Documation-M1000-Card-Readers If so, the presumed cost of shipping is the main thing that has kept me from adopting one of them. Well, that and being in debt at the moment from other recent acquisitions. And not having a clear space to set one down. And not having a keypunch, let alone room for a keypunch in my tiny little packed-full house. But I do think they look quite cool! And if I find solutions to all of those impediments before you find loving homes for all of those readers, I may yet adopt one of them. I was born just late enough to miss using punched cards, so I think that experiencing them would be fun since I've never learned otherwise by needing to use them in anger. -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: First VAX-11/730 VMS Boot! Now about VMS distros
On Jun 12, 2015, at 08:48, Richard Loken richar...@admin.athabascau.ca wrote: On Thu, 11 Jun 2015, Mark J. Blair wrote: Eventually, I'd like to run an older version of VMS than 7.3 on it. Preferably, something contemporary to when the 11/730 was still sold, or Gday Mark, it has been a long time since Rodondo Beach. Great to hear from you again! Still have those ARS33 teletypes? I must say, when I decided I needed to be an ASR33 owner again a year or so ago, it was a lot more expensive than those two that I got off the junkpile outside the EE stockroom in the Steele building at CIT! :) I seem to recall that you procured them for a PDP-8 restoration, but I don't recall which model (and it wouldn't have meant much to me at the time, anyway). Our VAX-11/780 came with VAX/VMS Version 2 on it and the documentation had that quaint early Digital quality that looked like it had been printed on a Teletype Model 35. Our VAX 8600 came with VAX/VMS version 4.X - this leads me to suggest that you do not want a version contemporary to the VAX-11/730 (probably v2 or 3). We ran VAX/VMS version 5.5-1 for many many years on our massive great VAX 8820, VAX 4000 model 500s, some VAX 2000s, and my VAX 3100/30. Later releases of VMS 5.X are IMHO a good version. I'd like something contemporary-ish. So I'll experiment with 3.x if I can find installation media/images, but perhaps compromise on 5.x for something not too new, but not too primitive. Maybe I'll think about some sort of drive emulation to let me easily swap OSes, and to save wear and tear on the R80? My cage is full already with the ethernet card in there, so maybe it should grow a Unibus extension? There's an unused spot in the TU80's cabinet that might fit a chassis. I have in my possession a Digital VAX/VMS software and documentation distribution on CDrom circa 1995 which includes VMS version 6.2. This is the complete standard distro from the time and came in two boxes measuring maybe 10 x 15 by 1 inch. I can send this to you for the postage if it is of any use. I also have a much larger complete OpenVMS VAX 7.0 distro on two TK50 cartridges (who knew?) and 10 pounds of paper docs in its original carton. Anybody want it? I think it survived because somebody thought it was an Alpha distro. Shipping of that would be a bit more money. I would be interested in procuring both of those in order to put them on my hopefully scan/image and send to Bitsavers and Archive.org before I die pile. There's already some stuff from this system in that pile, including a 11/730 hardware user's guide. -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: First VAX-11/730 VMS Boot! (was: Re: VAX-11/730 %BOOT-F-Unexpected Machine Check)
I'm having trouble with the password reset procedure (but will resolve it by the end of this message). When I run AUTHORIZE, I get this: $ run authorize run authorize %DCL-W-ACTIMAGE, error activating image SECURESHRP -CLI-E-IMGNAME, image file PIKE$DQA0:[SYS0.SYSCOMMON.][SYSLIB]SECURESHRP.EXE;2 -SYSTEM-F-PROTINSTALL, protected images must be installed I tried installing my new OpenVMS license pak to see if that would influence it, but it didn't seem to help. Took about an hour for my terminal emulator to slowly type in that 2400 line license file! Ok, let's try rebooting with the new license pak installed... Nope! @DQ0GEN I D/P/L F26200 86 D/P/L F2620C D/P/L F26200 6 D/G/L 0 00A80003 D/G/L 1 3 D/G/L 2 3FB86 D/G/L 3 0 D/G/L 4 0 D/G/L 5 1 E SP G 000E 0200 L/P/S:@ VMB.EXE S @ SYSBOOT SET VAXCLUSTER 0 SYSBOOT SET /STARTUP OPA0: SYSBOOT SET WRITESYSPARAMS 0 SYSBOOT CONTINUE %SYSBOOT-I-SYSBOOT Mapping the SYSDUMP.DMP on the System Disk %SYSBOOT-I-SYSBOOT SYSDUMP.DMP on System Disk successfully mapped %SYSBOOT-I-SYSBOOT Mapping PAGEFILE.SYS on the System Disk %SYSBOOT-I-SYSBOOT SAVEDUMP parameter not set to protect the PAGEFILE.SYS OpenVMS (TM) VAX Version V7.3 Major version id = 1 Minor version id = 0 %WBM-I-WBMINFO Write Bitmap has successfully completed initialization. $ set noon set noon $ spawn /nowait sys$system:startup.com spawn /nowait sys$system:startup.com %DCL-S-SPAWNED, process SYSTEM_1 spawned $ %DCL-W-NOLBLS, label ignored - use only within command procedures \SYS$SYSTEM:\ %DCL-W-PARMDEL, invalid parameter delimiter - check use of special characters \.COM\ $ set default sys$system set default sys$system $ run authorize run authorize %DCL-W-ACTIMAGE, error activating image SECURESHRP -CLI-E-IMGNAME, image file PIKE$DQA0:[SYS0.SYSCOMMON.][SYSLIB]SECURESHRP.EXE;2 -SYSTEM-F-PROTINSTALL, protected images must be installed $ Ok, now let's try the slightly different procedure at http://labs.hoffmanlabs.com/node/204 http://labs.hoffmanlabs.com/node/204 with the vaxcluster stuff spliced in... Much better! Much longer boot time, lots of complaining about terminated licenses (previous attempt to install them must not have worked), but I was able to reset the password. I'm not sure what was different about the other proceduer (maybe the /nowait flag?), and some of the lines don't even look applicable to a non-workstation. Now running the license pak script again, and the output looks a lot more promising. Forward progress continues! -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: using new technology on old machines. Was: PDP-12 Restoration at the RICM
On Jun 15, 2015, at 21:28, tony duell a...@p850ug1.demon.co.uk wrote: As am I. I've learnt a heck of a lot since I started (there is a common myth that there is something magic about a processor. This hobby has taught me to understand quite a few at the gate level). And the day I stop learning is the day I am in a pine box. In my opinion, the magic is inside the transistor. Once you bottle enough magic to make a good transistor, the rest is pretty straightforward. :) As an aside, I am not overly enamoured by the RPi. I think there are possibly better alternatives like the Beagleboards (?) which I need to investigte. Shockingly, I agree with you! The RPi is neat for what it is, but I have a mental hangup on openness, which the Beaglebone Black has more of (i.e., I think I could buy the main chip on it from DigiKey, unlike the Broadcom chip on the RPi. Not that I'm eager to route my own SDRAM bus... that's actually kind of hard, particularly with the open-source PCB tools I use for home projects). The BeagleBone also has lots more delicious IOs. This is one of my main dislikes with USB. It is so complicated that you have to use a microcontroller. Unlike any of the more sane interfaces that you can implement with simple logic if you want to. I have a love/hate relationship with USB. I liked moving away from having to figure out which way the danged plugs were wired at both ends for any given pair of devices. But on the other hand, a UART is dirt simple to implement, and I still use them for debug ports even on vastly complex FPGA-based stuff. I don't see async serial dying off any time soon. -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: using new technology on old machines
On Jun 15, 2015, at 21:40, tony duell a...@p850ug1.demon.co.uk wrote: Exactly. I don't do firearms at all (we have various IMHO ridiculous laws in the UK, but I do not want to start that debate) Sorry I even brought it up; I was just using it as an example of the different specializations that each person might wallow in. Guns, religion, politics and text editor preference are often too contentious to discuss in polite company. :) But if you are going to repair/restore something then IMHO it makes a lot of sense to have common spares around. Agreed! But you generally tend to accumulate those spares *after* you have been involved in that particular area for a while. Coming into it from scratch, you might not even know which parts you're most likely to need. And buying every common-ish part that you might need is an expensive proposition. But common TTL parts, transistors, etc are used in many machines, and if you are going to restore the real hardware you are (a) going to need them and (b) are going to need to now how they work so you can trace faults. Right. So coming in from scratch, you might buy a tube of 74LS00 instead of just the one that you need to fix one board, and so on for many other common parts. One method that works for me is that if you are buying a fairly cheap part, buy 10 of them and put the rest in stock. Or more than 10 if it is something really common. Agreed again! For example, the first time I had a Rifa paper-dielectric EMI filtering cap go incandescent on me (happened to be in a Tandy Model 12), I figured out the three or four kinds of much better poly film EMI filtering caps I'd need to replace them on sight in the Astec supplies that Tandy stuck in everything, and I bought lots of extras. But I don't have a single 2N3904 in my junk box, because I don't think I've had to replace one in the last 30 years, just based on the kinds of things I've been working on. So it's not my go-to part. Now, 10k resistors and 0.1uF ceramic caps... those things I use a lot. :) -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: Serial UNIBUS Repeater?
On Jun 15, 2015, at 21:20, tony duell a...@p850ug1.demon.co.uk wrote: Mine did start out as the 'packaged' system in the half-rack, and I intend to keep it in that cabinet. Obviously I will keep the CPU and R80, but I am not sure if the tape drive is the most useful third unit at this stage. In mine, an RL02 drive is the third unit of the rack containing the CPU cabinet, and the TU80 tape drive is too tall for that slot (though one of the later front-loaders would probably fit). If you don't need an RL02 drive, then i think the hole it would leave behind is just the right size for an expansion chassis. Hmm, if it's the same rack that originally had the RL02 in it, then there should be no top panel, as the top-mounted RL02 was meant to be opened without sliding it out. With an expansion chassis in its place, you should be able to get full top access to the expansion chassis without sliding anything in or out. That seems like it would be super awesome since you want easy access for swapping cards. And no need to run a BC11A cable between racks, either. I've played with the idea of making a top cover for my main rack that rests on the cabinet sides, straddling the RL02. If I unscrew the shipping bracket at the back of the RL02 then I could slide it out for pack changes, and leave other stuff like a terminal sitting on top. I usually seem to have stuff sitting on top of the RL02 and/or TU80 anyway, and then I need to shuffle the stuff around whenever I need to open one or the other. Ok, that's enough enthusiastic agreement for now. Off to the other thread for some more enthusiastic disagreement! :) -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: using new technology on old machines. Was: PDP-12 Restoration at the RICM
On Jun 15, 2015, at 21:59, tony duell a...@p850ug1.demon.co.uk wrote: Even though there are at least 4 different USB connectors Ok, you got me there! When I was working for a GPS startup, I used mini-B on everything I designed with USB (always devices, never hosts, and no need for USB OTG). Then we got bought by a cell phone company and now everything's a godawful mix of mini-B and micro-B, with OTG thrown in there, too. Grrr! IMHO USB got round the problem of null-modem cables by making them impossible. Which to me is not an improvement. I guess USB is OK when it works (like plugging in a memory stick) but a right pain to debug when it doesn't. And having read the standard there is much I dislike about it. Maybe this isn't the best time or place for this particular rant, but in my opinion, Windows' implementation of USB is fundamentally broken. It's a mouse, you stupid computer! You shouldn't need to spend a minute or more installing a new device driver for it! And you shouldn't need to install the driver yet again if I poke it in a different hole than I did last time! Every other *** OS on the planet is smart enough to say Oh, a mouse! I know how to use those! within a handful of milliseconds! (Take deep, cleansing breaths, Mark.) Ok, I feel better now. :) -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: using new technology on old machines. Was: PDP-12 Restoration at the RICM
On Jun 15, 2015, at 09:53 , tony duell a...@p850ug1.demon.co.uk wrote: I also think it is in the spirit of the computer - using what is available to fix a problem at hand. I think the arduino was overkill when an attiny (smaller, easier to hide) would probably serve just as well. Would you put plastic handles on a piecc of antique furniture? Would you make the seatboard for an antique longcase clock from MDF? Both are easily reversable, BTW. Sure! Temporarily and reversibly, of course, and I'd hope to replace them with proper stuff when possible. But to bring up an old computer system right now, I'll kludge in what I have available to get it running. In that respect, an Arduino-based baud rate generator could be considered test equipment rather than a component. If you have the ttl logic bits lying around and know how to use them, fine. Still would probably need debugging. FWIW I have made programmable dividers on a couple of occasions recently (one was a 100/120 flash-per-second stroboscope, the other was the transmitter half of a modem to talk to TDDs). Both of them worked first time. I guess it's just what I am used to. Exactly. And for somebody who doesn't already have a full stock of TTL parts on hand, a different solution may present itself. I play with gear from WWII military radios up through thoroughly modern electronics. When I work on a WWII radio, it might be considered cheating to poke at it with my Fluke multimeter, Tek DSO, HP spectrum analyzer or HP synthesized signal generator (the latter two of which are slaved to my GPS-disciplined frequency standard), but those are the tools I have on hand, so those are the tools that I use. -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: Serial UNIBUS Repeater?
On Jun 15, 2015, at 10:11 , tony duell a...@p850ug1.demon.co.uk wrote: I'm not specifically familiar with the 11/730, but what's wrong with just cabling up an expansion box the old fashioned way using BC11A cable? Nothing electtically... The problem is that the 11/730 mouting box (BA11-Z??) is a bit odd. The boards go in from the left. Cables end up going downwards (either straight down or over the top of the card cage, then down between the backplane and PSU). Then into a removeable tray on the bottom of the mouting box, round a flexible plastic sheet and to another tray fixed in the rack. The idea is to make the cables route nicely when yout slide the box in and out (something you have to do on the 11/730 to change the microcode tape or get to the main circuit breaker). That's a much better description of the 730's mechanical peculiarities than I came up with. I was more concerned with cable management between the two racks, since I have them in a tiny room where I need to roll them around to get access to the back (it's literally a tiny bedroom in a manufactured home... basically a doublewide trailer that's been fastened to a foundation after having the axles and drawbar cut off!). It's already tricky to roll the racks back into place without running over the power cables, tape drive cables, serial lines and power controller cable. But managing the cables in the cable tray area is another thing that needs to be done right. I am not sure how a BC11A cable would like being folded back and forth like that. The official way was, I think a board in the Unibus out slot of the 11/730 that had 3 40 pin Berg headers on it. This took 3 normal 40 way ribbon cables which went round the cable routing thing and to a similar board in the Unibus in slot of the expansion box. I think there were even bulkhead panels to route the cables to another rack cabinet. Three narrower cables sound like they would be easier to manage than one wide one. Based on the hardware user's guide that I have (and which I do plan to scan and share), I gather that UNIBUS expansion cabinets would generally be used in a configuration that's in a larger rack and has both TU58 slots on the front panel. I haven't seen one of those in person before. My system is the configuration that's in one or two short racks. The main one is completely filled by the RL02, VAX-11/730 and R80 drives, from top to bottom. The other rack contains the optional TU80, with an unused bay below it. I haven't measured the size of that unused bay yet, but it looks like it may be tall enough for a UNIBUS chassis. Maybe I could adapt one of my empty PDP-11/44 chassis boxes for use as an expansion chassis? Or another possible use for that slot could be for my Kennedy 9610 tape drive. The TU80 looks like it probably has a Pertec interface, so I should be able to add the Kennedy drive to the chain to get more BPI options in the system. Now that I have a computer with a Pertec interface running, buying/building a Pertec adapter for my Mac or Sun doesn't seem so important. Assuming I can bring up networking on the VAX that is, and that I can figure out how to do block-level stuff under VMS. -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: First VAX-11/730 VMS Boot! (was: Re: VAX-11/730 %BOOT-F-Unexpected Machine Check)
On Jun 15, 2015, at 09:50 , Richard Loken richar...@admin.athabascau.ca wrote: You need to read a little tome entitled Mastering VMS by David W. Byron or maybe The VMS User's Manual that came with VAX/VMS Version 5. I'll look for those. Thanks! ANd the /NOASSIST switch worked for me. I didn't even need to pre-initialize the tapes. I'll probably look into doing things the more traditional batch way once I have multiple terminals and/or networking set up, but for now it's a single-user/single-terminal system. -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: Reviving a VAX-11/750
On Jun 15, 2015, at 11:06 , Mattis Lind mattisl...@gmail.com wrote: Well. I am probably working on to much simultaneously. I am very guilty of that, too! :) Then I compiled your fork of tu58em on github. And it worked perfect. I didn't need to use the special vax mode that you have implemented though. Maýbe it is required only by 11/730? You could probably use Don's original tu58em, then. The 730 appears to have one 20ms timeout in a critical part of the drive initialization routine (which is entered repeatedly in normal operation, not just at power-up), and stock tu58em has a delay in that spot that is problematic. Maybe the 750 console code either lacks the timeout check or has a longer timeout period? The bad thing with the 11/750 is that is has so many socketed TTL gate array chips. Sockets are bad. And gate arrays are bad. In that sense I think the 11/730 is better since it is AFAIK based on mostly standard off the shelf chips. Mostly, if I'm not mistaken (I haven't gotten too deeply involved with the PCBs yet). There are a number of PROMs. -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: Updates
I hope that you and your wife are doing better now! -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: FPGA tricks - Re: using new technology on old machines. Was: PDP-12 Restoration at the RICM
On Jun 15, 2015, at 09:18, ben bfranc...@jetnet.ab.ca wrote: But alas the software does *not* support the older chips. You want to make a mod 5 years down the road, sorry we do not support that model any more. TTL needs to be stock piled now for the next +50 years. Good point. Just as TTL needs to be stockpiled, I think we should be in a habit of archiving virtual machines containing development software installed in a compatible operating system, so the software can still hopefully be used long after the original machines are obsolete. Much like we often use SIMH now for maintenance tasks to help bring up old machines that no longer live in an ecosystem of similar machines. -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: Reviving a VAX-11/750
On Jun 15, 2015, at 11:59 , tony duell a...@p850ug1.demon.co.uk wrote: I also may dump the console firmware PROMs at some point. I've already done some preliminary disassembly of the TU58 firmware. I am pretty sure I dumped all the PROMs and PALs in the CPU of my 11/730 (but not the ones in the R80) long before there was a bitsavers. I can see if I can find the dumps. What I don't have is the Remote Diagnostic ROMs (this was another pair of 2K*4 ROMs that plug into sockets on the WCS board and which run on the 8085). So no dumps of that. I have three WCS cards, including the one in my machine, but none of them have the remote diagnostic option. -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: using new technology on old machines. Was: PDP-12 Restoration at the RICM
On Jun 15, 2015, at 11:54 , tony duell a...@p850ug1.demon.co.uk wrote: Why not do it properly first time? What is the rush in bringing up a classic computer? And for a test, use the TTL pulse generator you have on your bench. I don't have one. I have a lot of test equipment, but mostly for RF work. If I needed to generate TTL pulses, I'd probably pull out a microcontroller development board of some sort, because that's what I have sitting around. Or even an NE555 astable (yes, with a decent capacitor it is stable enough for a baud rate generator, I've used it). Heck, I've worked on machines that used a 2 transistor astable multivibrator for the baud clock. Surely you have 2N3904s in the spares box? No, I have neither 2N3904s nor NE555s in my spares. I could replace an M1 Carbine trigger spring on the spot, or a HMMWV taillamp housing, or most of the tubes in a 1950s US military vehicular radio, or an AR15 recoil buffer, or an Enfield Mk. 2 firing pin, or countless other things. I could test a diesel engine injector for pop-off pressure and slobber, or pull diagnostic codes from an M923's antilock air brake system, or check a transmitter for spurs up to 2.9 GHz, or measure a TTL clock frequency to within 50 parts per trillion absolute accuracy. But I don't have a TTL signal generator. Not everybody has the same junkbox, background, interests, equipment or capabilities, so not everybody will do things the same way that you do. Should I criticize you for not having SAE grade 8 hardware on hand, or Bristo wrenches for working on a Collins PTO, or spare Packard connectors for a post-Korean vintage US military vehicle, or the right kind of grease for an M1 Garand bolt, or the special screwdriver for the tiny little center-drilled screws in a telephone patch plug, or an M1 carbine gas piston plug wrench, all of which I have on hand? (No, I shouldn't, and I wouldn't.) Incidentally, if certain horologists heard you would use MDF in an antique clock, you would be going home with a pendulum rod shoved where the sun don't shine ;-) Well, maybe I'd educate them that Underwood and Remington Rand didn't just make typewriters before they got that pendulum rod in very far. ;) -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: using new technology on old machines. Was: PDP-12 Restoration at the RICM
On Jun 15, 2015, at 12:15 , tony duell a...@p850ug1.demon.co.uk wrote: I am very worried that people would rather use a microcontroller than change a couple of passives. Can't anyone read a schematic and think The exact same argument could be made for somebody using an NE555 instead of discrete transistors to blink an LED, or discrete transistors instead of vacuum tubes to blink a neon glow lamp. For that matter, I might call somebody a slacker for blinking an LED with an NE555 instead of an LM3909. But LM3909s are no longer manufacturer or stocked. An NE555 only costs $.50 vs. about $1 for an ATtiny, but these days, folks under the age of 40 are a lot more likely to have an ATtiny (or more likely, an ATmega on an Arduino board) sitting on their desktop. -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: Serial UNIBUS Repeater?
On Jun 15, 2015, at 11:41 , tony duell a...@p850ug1.demon.co.uk wrote: My 11/730 was totally decabled to get it to me. I think I have most of the original cables, and most of the metalwork. I've read the descriptions in the hardware manual on bitsavers and I am not looking forward to routing all those cables... Oh well Sorry to hear that it's been decabled. Take your time to route those cables through the bottom pan properly, and based on my experience so far, I do not recommend trying to route anything but flat cables through the pan area. Route anything round up over the top and along the folding support arm (what I've been calling a gantry, but not necessarily correctly). For anything temporary, might as well leave the cabinet slid out and let the cable dangle. The 730 is nicely made for sliding in and out easily, but really not optimized for frequent hardware configuration changes. It's a nice idea for a system that is not going to change, but adding or removing cables for a particular peripheral option is going to be painful. Yup, you're exactly right about that. That's why I am thinking of adding a BA11K or something on top. That makes sense to me, particularly if you will not be constrained by the original rack configuration like I am. The 730 has limited UNIBUS slots anyway, so might as well use an expansion rack for anything you might change frequently. -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: Serial UNIBUS Repeater?
On Jun 15, 2015, at 21:55, tony duell a...@p850ug1.demon.co.uk wrote: [11/730] for that slot (though one of the later front-loaders would probably fit). If you don't need an RL02 drive, then i That's what they did. There was a third (later) packaged system with the CPU, an R80 under it and a front loading (Cipher F880) magtape on top. That is what mine started out as. Aha! I didn't know that. Makes a lot of sense, and takes up half the floor space compared to having a TU80 in a second rack. I think the documentation I have predates that configuration option. I am not sure if I got the top panel but if I did it is no longer on the rack... If you do have it, I wonder if it would be hard to add hinges for easy access to a top expansion chassis? -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: First VAX-11/730 VMS Boot! (was: Re: VAX-11/730 %BOOT-F-Unexpected Machine Check)
On Jun 12, 2015, at 07:57, Antonio Carlini arcarl...@iee.org wrote: Doesn't control-P on the console halt the machine on a VAX-11/730? It brings up the console prompt, but the (H)alt command just prints the PC rather than triggering a halt on the 725/730. Next time I work on the system (Tonight? Or maybe tomorrow... depends on how cool it is in the evening, as that box pumps out enough BTUs that I need to open windows!) I will try a password reset as described here: http://labs.hoffmanlabs.com/node/204 Oh yeah, I forgot to comment on this earlier: On Jun 12, 2015, at 04:01, Peter Coghlan cct...@beyondthepale.ie wrote: Once you get logged in to VMS, I think it should be possible to use EXCHANGE to poke around the console tape images on the file level. It might be possible to find the reason for the problem that way? I can poke around at the file level with my RT11 filesystem tool: https://github.com/NF6X/pyRT11 In fact, the image I've used to boot the system isn't exactly the one that you fixed for me, but rather a new one I created using its files and bootblocks, with several scripts added to try booting different root directories. On the 730, I don't think I can modify R5 in the boot command. Rather, I would need to either manually type in the whole boot sequence manually, or create a new boot script off-system. I chose the latter, and made a bunch of them to try probing different root dirs on both the R80 and RL02 drives. BTW, standalone backup was not helpfully installed on E on my R80, so once I crowbar my way in, I'll try running a backup under the full OS. And new replies have arrive while I was typing: On Jun 12, 2015, at 08:00, Peter Coghlan cct...@beyondthepale.ie wrote: You can get a free hobbyist license if you join whatever DECUS is called now. I joined a while back, but haven't requested license yet since I didn't have my system serial number handy. I'll pull the rack out and jot down the number before I leave for work this morning. [and an alternate set of password reset instructions] Thanks! This is very helpful, as I am a real VMS noob. My previous experience with it was just using it briefly in one or two classes, and running a canned script to perform backups as a graveyard shift operator (Great pay for a student! And a key to the machine room! And a staff account with no quotas, rather than buying limited time or fighting with everybody else for CPU cycles on a class-account cesspit server! Do homework on a Sun workstation instead of a Wyse terminal! Heck, run a sim on the C240 supercomputer! Giggle!). I can still hear that TU77 howling in my mind. Hmm, I wouldn't mind having one, with a matching 11/780... :) Back in the day, I really hated VMS for no other reason than I liked UNIX and embraced it with the natural snobbishness of a youth growing up in the computer environment of the 80s, where our computer was the best even though the other guy's crappy computer used the same 6502 running at the same clock speed (but mine really was the best, because it used a 6809 :) ). But now I want to learn about VMS and appreciate it for what it is. On Jun 12, 2015, at 08:11, Johnny Billquist b...@update.uu.se wrote: Avoid V5, though. I remember at the time that people was having serious issues with that version. V6 improved things again. I think DEC spent a fair amount of time to improve performance because of all the complaints about V5. V4 would also be good in some ways, but it's old and might feel limited if you want some modern software running... Modern software running on a 730... I don't know if I'll live long enough to wait for it to launch! :) -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: First VAX-11/730 VMS Boot! (was: Re: VAX-11/730 %BOOT-F-Unexpected Machine Check)
On Jun 12, 2015, at 04:01, Peter Coghlan cct...@beyondthepale.ie wrote: If the machine just sits there indefinately after loading the MSCP disk server, you probably don't have enough cluster votes to proceed and the best thing to do is perform a conversational boot which usually involves setting the least significant bit of register R5 to 1 before booting. How exactly to do this varies from processor to processor and I don't know how to do it for an 11/730. When you manage to do this and try booting again, you should get a SYSBOOT prompt and you could: SHOW VAXCLUSTER SHOW VOTES SHOW EXPECTED_VOTES SET VAXCLUSTER 0 SET WRITESYSPARAMS 0 CONTINUE to confirm that the issue is with cluster votes, turn off clustering and proceed with the boot process. Thanks, that works! I also turned off write lock, which makes it happier. Wow, that boot sure takes forever. What the heck is it *doing* for all of that time? :) And at the moment, it's still booting, as I sip my morning coffee. Just started printing like heck and beeping... Ah, it's printing all of the licenses that have terminated. Maybe I should have lied about the date? Looks like the hostname is PIKE. Sure glad my iPhone boots more quietly. VMS use not authorized on this node. I sure hope it won't enforce that before I can try a backup! Finally! A login prompt! And no clue about the passwords. Uh, how can I shut this beast down without a valid login? !? Great. :) -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: using new technology on old machines
On Jun 15, 2015, at 15:07 , Noel Chiappa j...@mercury.lcs.mit.edu wrote: One wonders why some manufacturer didn't realize there was money to be made in smaller cards (now less competition, but still enough demand to drive the prices up) and keep making them. Because the chip fab equipment that was used to make the dies in the spaller parts has probably already been retired in favor for equipment suitable for smaller process geometries, and there's no point in making dies with storage capacity smaller than what fits in the minimum die size dictated by the pad ring necessary for the I/O. There actually is a lower limit to memory capacity, beyond which the cost cannot be reduced and the die cannot be shrunk. We call such chips pad limited, as in the I/O pads dictate a minimum die size, and the die will cost almost exactly the same (save for minor yield variations) whether the middle is filled with gates or not. I don't think that the hangups of a very few people justify ignoring the economics of semiconductor manufacturing. -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: using new technology on old machines. Was: PDP-12 Restoration at the RICM
On Jun 15, 2015, at 14:56 , Dave G4UGM dave.g4...@gmail.com wrote: A friend of mine refused to buy modern SD Cards because there was no way he was going to fill them. Trouble is that although smaller SD cards were available they were way more expensive (being discontinued and therefore rare and valuable).. He struggled with buying a larger card only to waste most of it, or buy a smaller one and waste his money I had that same mental hangup when thinking about how I might design an SD card based TU58 emulator in the same form factor as a TU58 cartridge (still on my to-do list, by the way). How was I going to implement the user interface? It's not like there's much room for an LCD or buttons on the edge of a TU58 cartridge. Then it finally hit me: SD cards are cheaper than TU58 cartridges ever were. So why not just use the first 256k, ignore the rest of the card, and swap cards exactly the way one would swap TU58 cartridges, with one image on each card? Yeah, 99% of the card is wasted, but they're presently cheap and plentiful enough to ignore that. Ok, I might actually have the emulator read a file from a DOS filesystem rather than using the first 256k of raw blocks. But it'll probably just be a fixed filename with no controls to select a different one, and the expectation that an entire (cheap, plentiful) SD card will be devoted to each tape image. At least this way, other things can also be on the card, so it doesn't need to be wasted if not needed. Your friend should understand that the larger card that he would be wasting probably has less silicon in it than the older one with less capacity. The cheapest card that is reliable, fast enough and large enough for his task is the best one to get, even if it's much larger than he needs. Just one of the weird parts of the Moore's Law curve! Hmm, this reminds me that back in the day, floppy disks were expensive. We have it easy with cheap and plentiful SD cards nowadays. But maybe my perspective is different as an employed adult rather than a teenager with limited funds? Anyway, SD cards seem to be cheap enough to be nearly disposable nowadays. -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: using new technology on old machines
On Jun 15, 2015, at 14:19 , Noel Chiappa j...@mercury.lcs.mit.edu wrote: I think Tony's point was that someone who's into vintage computers ought to have a stock of suitable parts for them. Yes, that'll likely be true once they have been in the hobby for a while. But for somebody who has gotten into it recently, and otherwise hasn't had reason to touch a DIP packaged part since the early 1990s (even while being a full-time electrical engineer and full-time electronics/etc. hobbyist), it can't be taken for granted that they have a parts drawer full of misc. 74LS parts. I have a vast junkbox, and I regularly order electronic components both professionally and for my hobby... and I still don't have a lot of TTL parts on hand. -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: Serial UNIBUS Repeater?
On Jun 15, 2015, at 16:26 , Mike Ross tmfdm...@gmail.com wrote: Strobe Data make something like half of what you need: http://www.strobedata.com/home/unibusfw.html Unfortunately IIRC it's an 'if you have to ask the price you can't afford it' kind of deal... Interesting! Thanks for sharing! I could probably make one cheaper, but I couldn't make one cheap. :) Another approach would be to build a BC11A-equivalent cable using multiple narrower ribbon cables (as previously mentioned in this thread), and use the round-jacketed-shielded ribbon cable. The stuff isn't cheap, though, and a couple of round-jacketed 40-conductor cables probably aren't any more flexible than the Pertec tape drive cables I already have snaking about between the racks. -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: First VAX-11/730 VMS Boot! (was: Re: VAX-11/730 %BOOT-F-Unexpected Machine Check)
On Jun 13, 2015, at 14:29, Peter Coghlan cct...@beyondthepale.ie wrote: Did I say that? I meant: $ spawn /nowait @sys$system:startup.com (sorry) Aha! Now I understand. Ok, I have the SYSTEM password reset, and the license pak installed. Next task is to perform backups. First attempt to do that has presented my next learning opportunity: How do I respond to tape mount requests on the same console where I'm running BACKUP? When I get the request asking whether to create a new tape volume, it doesn't seem to respond to terminal input. -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: using new technology on old machines. Was: PDP-12 Restoration at the RICM
On Jun 15, 2015, at 14:27 , Robert Jarratt robert.jarr...@ntlworld.com wrote: This particular thread has all the hallmarks of one that *could* descend into a flame war. Thank you for avoiding that! I think we're doing ok. The same folks having a spirited debate in this thread are carrying on just fine together in other threads at the same time, so I don't think the fangs are being exposed. :) -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: 8-bit Computer TV Channel Use
I just noticed that the Si2137 and Si2177 tuners are now marked as factory special order and Mouser, where they were previously just marked New at Mouser. So my guess that those parts are a leftover tray with questionable future availability might be unpleasantly accurate. I'm still interested in pursuing a cheap tuner design to see if it goes anywhere. Even if it turns out that some existing composite to HDMI converter satisfies everybody, I think there would be interest in a small, inexpensive standalone RF demod to get composite video out of vintage home machines without internal mods, and Crazy Cat Lady could morph into that. Maybe it would involve custom hardware, maybe it would be a TV tuner dongle operated in SDR mode plugged into a Beaglebone with custom software, maybe it would be a general purpose SDR design that happens to be well-suited for video demod... figuring that out is the fun part for me. -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: 8-bit Computer TV Channel Use
On Jun 1, 2015, at 17:43, Chris Osborn fozzt...@fozztexx.com wrote: The color on the hi-res screens looks pretty good, but the vertical lines through the blocks on the lo-res screens isn’t quite right. The bottom 4 lines of text having color bleeding is normal, even on an Apple color composite monitor. The monochrome 80 column screen looks pretty good too. Well, you're right! The text looks like crap on an analog CRT, too. I updated my blog post with a few more pictures. Now I'm even more curious about the reports I've heard about having trouble with video conversion, since the first cheap converter I tried seemed to work OK with an Apple //c. Of course, it still lacks a tuner for the TV-connected computers, but I got the impression that the Apple II series was especially picky about its video converters. Maybe there's a different program I should try running that does weird stuff with video modes, like some game with particularly interesting graphics? I'm also interested in seeing what the converter will do with composite video tapped out from a Color Computer's innards. I seem to recall that it had some screwy video modes that required the user to keep hitting the reset button until the colors weren't swapped. -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: 8-bit Computer TV Channel Use
On Jun 1, 2015, at 17:43, Chris Osborn fozzt...@fozztexx.com wrote: Do you happen to have an old CRT TV around with composite input that you can hook up and compare to, just for yourself? I’ve got an Amdek Color I and Apple IIc Color Composite here that I’ll try to take some sample pictures of. Hmm, I should be able to try it out with a Commodore 1080 monitor. -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: 8-bit Computer TV Channel Use
On Jun 1, 2015, at 19:31, Chris Osborn fozzt...@fozztexx.com wrote: This one looks exactly like yours, but it’s even cheaper! I wonder if it’s the same? http://www.amazon.com/dp/B009A6PJKQ When you get it, we can compare pictures of their innards. Mine has a PCB with blue soldermask. Most of the functionality appears to be in a single QFP, probably with a central ground/heat slug based on the vias on the bottom side of the board. The top of the chip appears to have been sanded to remove the markings. -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: 8-bit Computer TV Channel Use
On May 23, 2015, at 10:28, Steven Hirsch snhir...@gmail.com wrote: On Sat, 23 May 2015, Chris Osborn wrote: On May 23, 2015, at 8:24 AM, Mark J. Blair n...@nf6x.net wrote: In the middle will be some FPGA to perform any necessary magic. I've been looking at a prohibitively expensive ($115) one that has enough dual-port RAM blocks to support a frame buffer. Getting an acceptable combination of crisp 80-column text and proper color aliasing from a converter is decidedly non-trivial. Even back in the day, I believe it involved swapping the cable between a monochrome monitor and a color one. I expect that this universal converter idea will require a way for the user to tell it whether they want color or monochrome video at the moment (and might as well let them choose what color phosphor to emulate). That way, an Apple II user who wishes to use modern displays could switch between 80 column mono mode for text or color mode for graphics, without swapping cables or displays. I own one of just about every commercially available (and hobby) converters and precisely none of them provides a universal solution. Some give great displays from an Amiga and suck for anything else. Of my two (pricey) CVP CM-345S converters, only one provides useable display from an Apple IIGS. My GBBS-8220 can occasionally be coaxed into giving a solid display from a Color Computer 3. The list goes on... Aha! I've heard Nth-hand accounts of trouble getting vintage computers to play with video converters, but you sound like one of the folks with firsthand experience. If transparent, tweak-free emulation of a classic CRT display were easily doable, it would have been done by now. Agreed! I envision that the converter should have some sort of smarts to help it figure out what sort of input it sees, but even in the ideal case it'll probably need some capability for user tweaking or mode switching for corner cases. On May 23, 2015, at 10:41, tony duell a...@p850ug1.demon.co.uk wrote: Problem with TINY parts is soldering them :-). The SAW filters I used (with a conventional tuner module) were round metal cans about 0.5 in diameter with 8 pins on IIRC a 0.1 spacing. Very easy to handle. If you are designing something for others to build (even in principle, i.e. you are making it an open design) then using impossible to handle parts is a bad thing if there are alternatives. The SAW filters I used are small enough that my 46-year-old eyes have trouble seeing them without a magnifying glass. :) I do almost all of my soldering under a stereo microscope any more. But I can solder down to 0201 discretes that way, although I don't like going smaller than 0402. I don't have a lot of experience with hot air soldering yet, but it has become quite available to hobbyists, with hot air systems now available for around $100. The Maker movement has done a lot of good in the area of making surface mount soldering more approachable by Joe Random Hobbyist. Now, one of the engineering problems I'd need to solve would be how FEW PCB layers I could get away with using that FPGA. 16+ layers is not uncommon for full die escape, but layer counts like that are far too expensive at the volumes this thing might sell in. Cell phones have high layer counts, but only because they sell in huge volumes. I favor Xilinx FPGAs since they're what I use in my day job, and those are all BGAs. I would not offer this device as a kit in any case; I've helped Ian out doing rework for US FreHD customers, and even good old through-hole soldering can be hard for folks without a lot of experience. I'd rather design for automated assembly than spend a lot of time on tech support for kit builders who had trouble. With a BGA on it, the board's going through a reflow oven anyway. And IIRC US NTSC uses AM sound (Europe uses FM). I think you can forget about stereo sound, since I doubt any home computer had a stereo RF modulator. No, I think it's FM. I recall listening to TV audio on my US FM tactical mil radios whose frequency coverage extended over the bottom 2-3 VHF TV channels, back before they turned off the analog broadcasts. I agree that stereo support isn't needed, as stereo TV post-dates the computers in question if I'm not mistaken. But if I do the final demod digitally in an FPGA, then adding AM support wouldn't be a big deal if needed. Be warned that there are many versions of PAL. That sounds like a deep rabbit hole to fall down! It might result in a case of if you want me to add support for the computers from your country, send me one so I can develop with it. But this is also a point in favor of using an FPGA: Fairly major architectural changes just look like firmware upgrades to the end user, who can remain blissfully ignorant of my development pain. :) If I use one of the Zynq chips (which I'm currently favoring), then upgrades can probably be as simple as swapping
Re: 8-bit Computer TV Channel Use
On May 26, 2015, at 14:07 , Chris Elmquist chr...@pobox.com wrote: If you do end up building a custom solution, I have a feature request :-) It would nice if the device was also a frame grabber that could, under command, snap one or more frames of the legacy video and export it over USB perhaps. That was already on my possible-feature list! ;) If I do end up using a Zynq FPGA, then hanging things like Ethernet and/or USB OTG would be cheap to add. Those wouldn't be my first priorities to implement in firmware, but I should at least include stuff options for the connectors and PHYs on the PCB. I'm not sure yet whether I'd start with a dev board or go straight to a custom board. The Zybo board is cheap and has the cheaper Zynq chip that I'd like to target, but it lacks good physical connections for a couple of relatively high-speed DACs, and it only supports 720p HDMI output because it lacks a dedicated HDMI PHY. I could get 1080p and an FMC connector out of the much more expensive Zed Board, but it uses a larger Zynq chip that would be prohibitively expensive for this project, and if I had to build a board with an FMC connector for my analog front end then I'd already be making a board that's too advanced for me to solder up at home, so I might as well thrown down the FPGA, too, rather than spending $500 on a not-quite-right dev board. Sigh... This would allow us to document operation of legacy software with high quality frame grabs since persumably you'd have access to the image in a relatively good quality domain before you turned it into DVI/HDMI or whatever. Agreed! Grabbing some live video might also be an option, but I think that would be a smaller incremental value add than getting high quality single frame grabs. BTW, every good project deserves a good project name. I'm tentatively calling this one Crazy Cat Lady. It has a nice ring to it. -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: Unusual stuff inside computers
On Aug 2, 2015, at 19:10, William Donzelli wdonze...@gmail.com wrote: And some 1950s military radio manufacturers, who screen printed schematic diagrams onto cloth and stashed them inside the radios. If you are thinking about that early GRC stuff, that was silk! Oh wow, I thought it was something like Rayon. -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: RS-232 Tx / Rx monitoring LEDs?
Those little RS232 testers with LEDs built into a double DB25 connector box are usually just made of LEDs and resistors connected to each signal line. They can load signals enough to cause problems at high speeds, with weak drivers, or with long cables, but usually they don't cause problems. If you're concerned, you could always include jumpers or switches to disconnect the LEDs when they're not needed. Of course, buffering the TTL signals eliminate any such problems. But on the other hand, using two LEDs connected with opposite polarities on each RS232 level signal lets your discriminate between driven positive, driven negative, and open. That can come in handy when debugging things where the other end may or may not be driving properly, or may be mis-wired. For an example, feel free to take a look at this little modular jack RS232 tester that I made: https://github.com/NF6X/YostTester/blob/master/YostTester.pdf The red/green LED pairs show whether each line is high, low or open. Resistor values may vary depending on the LEDs that you choose. -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: RS-232 Tx / Rx monitoring LEDs?
On Aug 20, 2015, at 09:54 , Paul Koning paulkon...@comcast.net wrote: Ok, but when you refer to drive strength I assumed you were talking about current, not voltage. By that measure totem pole outputs are pretty much symmetrical. Again, CMOS totem pole outputs are pretty much symmetrical, but TTL totem pole outputs aren't even close. Looking at a Fairchild 74LS04 datasheet, I see a 20x difference in recommended drive-high current (Ioh = 0.4mA) vs. recommended drive-low current (Iol = 8mA). And the voltages are correspondingly different, too: at rated drive current of 0.4mA, Voh = 2.7V (min) to 3.4V (typ) with a 5V supply, while Vol is 0.35V (typ) to 0.5V (max) at 8mA drive current. So that's 1.6V drop from Vcc while sourcing a mere 0.4mA, vs. 0.5V rise from GND while sinking 8mA. Totem pole outputs just mean that the output driver actively drives both up and down, with two stacked drive transistors. It does not imply that the drive strengths are even close to being equal, particularly when we're talking about TTL logic in a vintage computer. Incidentally, TTL inputs also present asymmetric loads for high vs. low inputs at about the same ratio (18x input current ratio in the 74LS04 example when driven at the input thresholds), and have asymmetrical input threshold voltages. So unloaded TTL output voltages aren't relevant if we assume that the output is driving a TTL input of the same logic family. Even if a TTL output appears to drive all the way up to Vcc with no load, it won't once it's driving a typical load. So you might think of those TTL totem pole drivers as being symmetrical when they're strictly driving TTL inputs of the same family, since the TTL inputs and TTL outputs are designed to work together. But they're very strongly asymmetrical when driving things other than TTL inputs, such as the LEDs in question here. -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: Indianapolis: More classic computing equipment than I can shake a stick at.
On Aug 23, 2015, at 13:52, Maxx Wood max...@gmail.com wrote: Amiga 2000HD (boots, but I don't have a keyboard or mouse, and the floppy drives continuously seek) If you're referring to a 1-track click each second, then that's normal for an Amiga. It's part of the disk change detection routine. There were lots of noclick utilities that patched the code to seek in one direction rather than back and forth, so that the clicking would stop once the heads reached the track 0 sensor. -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: RS-232 Tx / Rx monitoring LEDs?
On Aug 20, 2015, at 06:27, Paul Koning paulkon...@comcast.net wrote: Totem pole outputs have comparable drive strength in both directions, that's precisely their purpose (to provide symmetric rise/fall times when driving capacitive loads). That's true for CMOS outputs. TTL outputs pull down much more strongly than they pull up, which is why older designers are still in the habit of driving LEDs with active low outputs even though active high outputs work just fine with modern CMOS logic. Look at nearly any TTL datasheet, and note that VOL is much closer to ground than VOH is to VCC. -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: Where to get a Vax or microvax
On Jun 29, 2015, at 10:23 , Guy Sotomayor g...@shiresoft.com wrote: You *know* you have too much stuff and it's packed too tightly when you can lose a VAX 11/780! This reminds me of when I was exploring a surplus yard, and found a *fire truck* buried in a pile. Walked right by it a few times before I noticed it. I also lusted after an 11/780 as my first VAX, but compromised on a much smaller and slower, but much more practical 11/730 system when one happened to turn up. -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: Where to get a Vax or microvax
I still think I would enjoy acquiring an 11/780 series machine someday, when my wallet recharges and I've had time to excavate enough room out in my barn. But for now, I'm pretty stoked just to have my little 11/730. -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: Where to get a Vax or microvax
On Jun 29, 2015, at 01:22 , devin davison lyokob...@gmail.com wrote: My main place for looking for hardware has been ebay, although most of what im seeing is untested and expensive. Is there a better place to find older machines like this? Back to the original topic: By posting your interest in joining the VAX club here, you've already taken the first step towards getting one. As I got into retrocomputing a couple of years ago, I found that things started finding their way to me once the established collectors learned that I was looking for them. Keep your eyes open and be patient, and good hunting to you! -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: Unusual stuff inside computers
On Aug 1, 2015, at 21:22 , drlegendre . drlegen...@gmail.com wrote: That's an old joke. Some (newb) asks How do you switch it on, i want to play Spacewar (or whatever), cagey user says You put a dollar in one of these slots... ;-) I guarantee it. That's my number one theory, followed by some kid just absentmindedly poking the dollar bill in the hole, then losing his grip. -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: Unusual stuff inside computers
I found a dollar bill inside an Apple Monitor II. It appeared to have been folded into quarters and then pushed through one of the cooling slots on top of the monitor. The monitor and matching IIe computer look like they came from a school based on the property numbers engraved onto them. I've made up all sorts of theories about how some kid lost his or her dollar bill in that monitor! -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: Unusual stuff inside computers
On Aug 3, 2015, at 14:51 , ben bfranc...@jetnet.ab.ca wrote: Written on the drive, is a lot different than paper floating around inside The bad blocks were written on the drive in the sense that they were written or printed on a paper label stuck to the top of the drive, not stored digitally on the drive platter(s). I may be mistaken, but I have a memory rattling around in my head of the bad block list even being printed on greenbar paper at final test, which was then cut with scissors and Scotch taped to the top of the drive. So, they were very literally written on the drive in layman's terms. -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: This Hobby Is Actually Useful!
Once I tried my first Metcal MX-500 series iron, I never went back. With proper tip selection and technique, the same pencil iron will work for anything from 0201 components to PL-259 connectors. And it heats up and stabilizes in under 30 seconds from a cold start after a tip swap. I've spent a lot of hours swapping 0201 and 0402 inductors and caps with a pair of Metcal irons and a microscope while tuning up GPS receiver front ends in my day job. -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: Unusual stuff inside computers
On Aug 2, 2015, at 12:15, William Donzelli wdonze...@gmail.com wrote: Turning this discussion on its head, I wonder if I'm the only one to stash manuals and setup CDs in the cases of my systems. Has anyone ever picked up an old system and found system documentation inside? Just wondering if I'm the exception... Just you and IBM. And some 1950s military radio manufacturers, who screen printed schematic diagrams onto cloth and stashed them inside the radios. The schematics were secured to the inside of the radio with a length of cloth ribbon, then folded up tightly and stuffed into a metal tube secured to the radio chassis. -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: Time to dig out some of my DEC XX2247 keys
On Jul 15, 2015, at 18:03 , Chuck Guzis ccl...@sydex.com wrote: But it sounds as if these XX2247 keys aren't particularly rare, nor are they beyond the possibility of duplication. Heck, I could crank out at least 40 of them tonight with tools and supplies already on hand (an XX2247 to copy, a tubular key copying machine, a box of blanks, and a metal stamp set). But I closed my eBay account, so I guess I'll just need to pass on that extra $4000 of income. :D -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: PDP 11 gear finally moved
If I may go back to the original post topic for a moment, what model is that line printer that is pictured? I'm on the lookout for a DEC LP32 to go with my 11/730. Now on the topic of capacitors: The only component type that I replace on sight at this point are the Rifa paper-dielectric EMI suppression caps. Had one go incendiary on me so far, and I do a replace-on-sight routine on them because my hypothesis of the failure mechanism(*) leads me to believe that they're all likely to burn up once the plastic shell has developed any cracks. They're easy to recognize: Rectangular, with transparent yellow plastic housings, which are usually crazed with fine cracks. Different caps which should not be subject to the same failure mechanism are easily available. (*) Paper dielectric is said to absorb moisture from the atmosphere if not sealed. So, I presume that once the yellow plastic shell cracks from old age, moisture gets in, and then the caps break down under power. I replace these with poly film safety-rated caps with suitable ratings, since the poly film shouldn't absorb significant moisture even if the housing seal fails. -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: PDP 11 gear finally moved
On Jul 20, 2015, at 18:02 , Tothwolf tothw...@concentric.net wrote: I replace wax paper types with polyester (mylar), polystyrene or ceramic discs, depending on how they are used in the circuit (note however that for wound foil types, modern replacement parts do not mark the outside foil, which needs to be at ground potential in many tube circuits, otherwise the circuit can pick up noise and hum). Funny that you mentioned that! I just watched a YouTube video today about how to experimentally determine which lead is connected to the outer foil for applications where that's important. Modern film caps may have a stripe on one end, but it doesn't appear to reliably indicate which lead goes to the outer foil. -- Mark J. Blair, NF6X n...@nf6x.net http://www.nf6x.net/
Re: Common Maxtor MFM drive failure mode -- any ideas?
> On Oct 24, 2015, at 14:22, Al Kossow <a...@bitsavers.org> wrote: > > On 10/24/15 11:40 AM, tony duell wrote: > >> Most likely those ICs are head switch/preamp devices and the servo head >> preamplifier. They are very likely to be custom. >> > > Silicon Systems was a common supplier in the 80s to mid-90s, which is why > their > Storage Products data books have been scanned. Just thought I'd mention that my first "real" job was at Silicon Systems. Started as an applications engineer for motor drivers, then moved into chip design for interface controllers. I don't think I have any old databooks any more. Glad to hear that they're being preserved. -- Mark J. Blair, NF6X <n...@nf6x.net> http://www.nf6x.net/
Re: IBM System/32 available
> On Nov 10, 2015, at 07:55, Paul Berger <phb@gmail.com> wrote: > > For the burn in on the CRT, only half of the CRT is used so you can rotate it > 180 degrees if that has not already been done. That also works for 3741 key > to diskette machine, same display unit. I only noticed burn-in on the lower half of the CRT, so this unit probably has another lifetime left in its display. > On the disk drive there is a head lock back top left should be locked when > moving and I believe there is also a spindle lock. The head lock lever was "OFF" as I found the unit, so I rotated it to the "ON" position. If there's a spindle lock, it wasn't obvious enough for me to notice it. -- Mark J. Blair, NF6X <n...@nf6x.net> http://www.nf6x.net/
Re: PDP 11/03
> On Nov 10, 2015, at 05:56, Noel Chiappa <j...@mercury.lcs.mit.edu> wrote: > > (Actually, although there are only 10 pins, it looks like the connector > housings will hold 14-pin shells, so it you want to not have to carefully > align the cable before plugging it in, go for 14's. Haven't tried this > personally - yet - so take that one with a grain of salt!) That's precisely what I did for my little DLV11 to modular adapter. I'll share a picture later this morning. The DLV11 housing is wide, presumably to allow for wider ribbon cable connectors. I used a 14 pin housing to make it easier to line the connector up in the back of a dark equipment rack. For my discrete wire cables, I've been using 10 pin housings with the keying pin blocked off, but 14 pin housings should also work. I keep a supply of the crimp pins on hand along with 1, 2, 3 and 10 pin housings to cover DLV11 cables plus the common varieties of jumpers I often need to cobble together. I can share part numbers if anybody would like me to. -- Mark J. Blair, NF6X <n...@nf6x.net> http://www.nf6x.net/
Re: IBM System/32 available
The seller emailed me some pictures. It does look pretty good, aside from some peeling paint on the front of the floppy drive compartment (I think) sheet metal panel, and the expected yellowing of the keyboard surround plastic.. This model has the keyswitch option, which is the only recognizable variation I identified based on a quick skimming of the manuals the other day. I can't tell whether it has the band printer or dot matrix option, but that should be easy to determine once I open the top cover. I should be seeing it in person in a couple of hours, and I'll try to dig up more details. I've emailed Mike about whether he wishes to claim it, but I haven't heard back yet. But whether I help a buyer out, buy it myself (must resist temptation!) or just take pictures of Mike's new computer to share, it'll be fun. I'll share the seller's pictures later this evening, too, if he doesn't mind. -- Mark J. Blair, NF6X <n...@nf6x.net> http://www.nf6x.net/
Re: IBM System/32 available
> On Nov 9, 2015, at 19:12, Mike Ross <tmfdm...@gmail.com> wrote: > > Sorry for being out of touch: in transit from NZ to NY and crazy busy. No > news my end but plan to speak to seller and visit system towards end of > week. I know at least a couple of you have emailed me privately; sorry for > not responding but will update ASAP. I'd *like* to claim it for the > Corestore but there are shipping costs and logistics issues. Shipping something like that to NZ must cost a fortune! I was surprised how much it cost me to ship a Timex-Sinclair TS-2068 back to its owner in Canada today, and it's just a bit smaller. ;) Anyway, after looking at it, I'd say that it's worthy of your attention if you would like to add another one to your fantastic collection. It looks to me like it'll clean up nicely. Let me know if you would like to meet for a cup of coffee while you're in the area. I might have to be in the office in Irvine, but there's a good chance that I'll be available this week. -- Mark J. Blair, NF6X <n...@nf6x.net> http://www.nf6x.net/
