Re: PDP-12 Restoration at the RICM

If you haven't yet found one, I have spares for the switch cover - I have an entire console and the backplanes (with the cards) whose machine was disassembled out from underneath them. JRJ On 5/10/2015 9:45 AM, Michael Thompson wrote: Sorry, I sent the message before I was finished. The CRT

Re: RLV11 Debugging

BR level is the bus request level for an Interrupt. BR 4 is typical. The RLV11 apparently asserts BIRQ L, pin AL2 - which on the 11/23 would be BIRQ4 L. I don't think the RLV11 offers any other choice. The RLV11 print set (bitsavers) has the switch settings on page 4 of the PDF. The RLV11

Re: test equipment / Re: Z80 / Z84C Swap (Doh!)

You might check EEVBLOG on Youtube. The guy's a blast and covers what you are asking about. He indicates 8 bits is really not to his liking at all, to go for more. He also goes over the sampling rate of some of the USB DSO's out there. EEVBlog #13: https://www.youtube.com/watch?v=JTG6jWL0ZqA

Re: Shugart 800-8 media centering problem

On 8/15/2015 1:55 PM, tony duell wrote: Certainly one of my thoughts along the way. But, the spindle cone does not rock or anything like that. And, I switched the clamping part out with another drive - neither was affected by the swap. It strikes me that there are 3 main subassemblies

Re: Shugart 800-8 media centering problem

On 8/15/2015 3:13 PM, Jay Jaeger wrote: To make matters worse, that test with the first SA 801 managed to smoke the 24V power supply on this system, so now I have to pull it all apart, and pull out the regulator transistor which is mounted from the reverse side through to the board

Re: Shugart 800-8 media centering problem

On 8/15/2015 8:31 PM, Jon Elson wrote: On 08/14/2015 02:58 PM, Jay Jaeger wrote: No, I didn't write any of what was quoted. ;) If one is going to remove the entire message quoted, then it probably makes sense to delete the wrote line as well. ;) The way most of the old 8 floppies work

Re: Shugart 800 spindle bearings (Re: Shugart 800-8 media centering problem)

- they allow a tiny bit more rock. JRJ On 8/17/2015 4:22 PM, Jay Jaeger wrote: Well, in the process of repairing the Altos power supply I managed to break the center lead off of the TIP31A that feeds the 2N3055 series pass transistor. This time, I need to order parts. In the meantime, I swapped

Re: RLV11 Debugging

On 8/18/2015 7:46 AM, Paul Koning wrote: On Aug 17, 2015, at 10:48 PM, Jay Jaeger cu...@charter.net wrote: BR level is the bus request level for an Interrupt. BR 4 is typical. On Unibus machines, more of the BR levels were used. The rule of thumb was BR4 for slow devices (like

Re: PDP-12 Restoration at the RICM

On 8/17/2015 1:51 PM, Rich Alderson wrote: From: Jay Jaeger Sent: Sunday, August 16, 2015 3:18 PM On 8/16/2015 9:00 AM, Michael Thompson wrote: We did a lot more debugging on the TC12 LINCtape controller. Second gut hunch is that it would be hard to see how the drive could cause

Re: test equipment / Re: Z80 / Z84C Swap (Doh!)

nutcase, lol - but he does seem to get some good info across, in between the audible glamour. On Mon, Aug 17, 2015 at 9:54 PM, Jay Jaeger cu...@charter.net wrote: You might check EEVBLOG on Youtube. The guy's a blast and covers what you are asking about. He indicates 8 bits is really not to his

Re: QIC-24 data analysis

On 8/16/2015 11:19 AM, Chuck Guzis wrote: On 08/16/2015 08:24 AM, dwight wrote: I left a note there about using CRCs to do data correction. It is a simpler method for software than normally use. I posted a link on VCF about using GNU CRC RevEng--a great little utility to aid in

Re: Shugart 800 spindle bearings (Re: Shugart 800-8 media centering problem)

On 8/17/2015 11:14 PM, tony duell wrote: Well, in the process of repairing the Altos power supply I managed to break the center lead off of the TIP31A that feeds the 2N3055 series pass transistor. This time, I need to order parts. Do you? The centre lead (collector) is connected to the

Re: RLV11 Debugging

On 8/18/2015 11:33 AM, Johnny Billquist wrote: On 2015-08-18 15:09, Jay Jaeger wrote: On 8/18/2015 7:46 AM, Paul Koning wrote: On Aug 17, 2015, at 10:48 PM, Jay Jaeger cu...@charter.net wrote: BR level is the bus request level for an Interrupt. BR 4 is typical. On Unibus machines, more

Re: DEC Fiche EP-M8436-MA-A

MA == Module Assembly. These fiche have BLUE tops. I have one that is slightly newer: EP-M8436-MA-B . In my case, it is part of the VTERM Fiche set. (Mine is VTERM-000171). M8436 - VT278 CPU, Revs A, C M8437 - COMM Adapter, Revs A, C and D M8439 - RL01/RL01 Disk Controller, Revs A, B and C

Re: More on manuals plus rescue

On 8/18/2015 8:35 PM, Shoppa, Tim wrote: IA saturates the channel. Jason and IA are deliberately working to redirect all search traffic to IA from the original mirrors by constantly creating useless 'new' content that Google thinks is real. I have watched over time as the volume of

Re: Vintage Software Copyright

On 8/21/2015 10:27 AM, Johnny Billquist wrote: And I don't know much about anything for non-DEC stuff. So while I hope there are copies of stuff around, think some before redistributing it. Johnny Some other licenses (or lack thereof) that make software readily available that I am

Re: De-yellowing

So, how does one de-yellow something? I have a VT-100 and some other gear that could use that process. JRJ On 8/21/2015 1:15 PM, Evan Koblentz wrote: Going to be de-yellowing a //e Platinum this weekend. Check out this picture of the top cover. You can see the non-yellowed part on bottom.

Re: Vintage Software Copyright

On 8/21/2015 4:34 PM, Fred Cisin wrote: Where would MICROS~1 be if Gary Kildall were to have been litigious? How so? Digital Research spurned IBM, and would have had to take IBM on as well as Microsoft. Litigious or not, it would have been a seriously uphill battle. JRJ

Update on SA-800 Problem

Well, the Altos ACS-8000-2 power supply is all back together and working again, in reasonable health. And, as I posted a few days back, I swapped out the bearings. Unfortunately, that does not seem to have helped. Now that the problem child is the second drive, though, I was able to put a

Re: Update on SA-800 Problem

On 8/22/2015 12:20 AM, Chuck Guzis wrote: On 08/21/2015 06:46 PM, Jay Jaeger wrote: One other thing I have noticed is that sometimes after a read problem on the bad drive the FD 1791 floppy controller chip seems to get into a snit that even a reset does not cure - I have to cycle power

Re: Sign magnitude, one's complement, two's complement

Univac 1100 series - one's complement. On 8/22/2015 4:23 PM, Sean Conner wrote: For my own morbid curiosity, and because it came up on another mailing list I'm on [1], what machines commercially avaialble were sign magnitude and one's complement? Every machine I've encountered was two's

Re: A tale of woe, including carelessness, stupidity and laziness....

On 8/22/2015 4:11 PM, Eric Smith wrote: In my mostly misspent youth, I once had the opportunity to visit a facility where a now obscure supercomputer was developed. The product manager was showing me around. That wasn't Astronautics' ZS, by any chance? I ask, because I know some folks

Re: A tale of woe, including carelessness, stupidity and laziness....

On 8/22/2015 12:55 PM, Tapley, Mark wrote: Jay, this is a really great post. I feel really bad for you - having the same piece of equipment go bang/flash more than once would have been totally demoralizing to me - but I really admire both your tenacity and your willingness to share

Reversed Electrolytics redux

On 8/22/2015 2:41 PM, Jay Jaeger wrote: Unfortunately, bearings did not help the floppy drive, so now I am busy taking the floppy power supply I got with my FD 100-8, making sure it is up to spec to use with the Shugart (and correcting that if needs be), and making it safer (mains fuse

A tale of woe, including carelessness, stupidity and laziness....

What follows is a tale of carelessness, stupidity and laziness. So far, I haven't found an excuse to add ignorance to the list. ;) As you may recall, I was testing an 8 floppy drive that was reading inconsistently on an Altos 8000 system, when, while testing with a replacement drive, the 24V

Re: Larry Niven's Altair

On 8/20/2015 9:47 AM, Paul Koning wrote: On Aug 20, 2015, at 10:30 AM, Jay Jaeger cu...@charter.net wrote: On 8/20/2015 3:32 AM, Randy Dawson wrote: Who picked this up - I may have some cash for the buyer to mate it with my new ASR33, on its way via crate and freight. Anybody got

Re: HP 5480A, or, obscure HP instruments / was Re: More on manuals plus rescue

At least, under Google and eBay, one can add exclusionary terms: hp 9100 -printer -scanner Seems to do pretty well under Google. Under eBay I had to add a lot more exclusions, and ran out of room. JRJ On 8/20/2015 7:11 AM, tony duell wrote: They reuse numbers for what I call marketing

Re: Power supply connector pin crimping, and 8-inch FDD power connectors (another chapter in the Quay 900 saga)

On 8/20/2015 10:16 PM, Eric Smith wrote: It turns out that even though this bizarre variant of the 9406 uses the Shugart pinout for the data connector instead of the MPI pinout, and uses the same DC power connector as the Shugart, instead of the header used in normal MPI 9406 drives, the DC

Re: Shugart 800 spindle bearings (Re: Shugart 800-8 media centering problem)

On 8/18/2015 4:11 PM, tony duell wrote: Yeah, but the TIP31A part is cheap, and is free air mounted on its leads - it isn't screwed down. I'd rather do the repair nicely. Anyway, it Sure... What I would do is bolt a tag + wire onto the tab of the old transistor (don't tell me you

Re: QIC-24 data analysis

On 8/16/2015 6:29 PM, Chuck Guzis wrote: On 08/16/2015 03:20 PM, Jay Jaeger wrote: One issue with the capstan idea, though, would be direction. Capstans really want to pull. Not very good a pushing. ;) So if you did that, and you wanted to direction operation (required if you can't

Re: PDP-12 Restoration at the RICM

On 8/16/2015 9:00 AM, Michael Thompson wrote: We did a lot more debugging on the TC12 LINCtape controller. We saw a 500ns glitch in the LMU MOTION signal that corresponded to a short slowdown in tape speed. We will investigate this next week. We entered the LINC instruction to check a

Re: Probs w. M3119 CXY08 MUX on VAX VMS 7.3

On 8/17/2015 1:18 PM, Holm Tiffe wrote: Johnny Billquist wrote: [..] Since I'm a total VMS Noob I now have some Questions: .. have I missed something? .. is the CXY08 bad? .. what could I try next? ...is there some diagnosting software for the CXY08 existing for VMS and if yes,

SA-800/801 saga continues / schematic request

Anyone out there have: 1) The Schematic for the newer SA-800/SA-701 board part number 25229.1 ? (It might also go by 25228 or 27121). The SA-800 maintenance manual on bitsavers from Feb 78 describes the original discrete board (such as I have on my Altos in the SA-800s) and an LSI-based board

Re: 9-Track 1/2 Tape Drive Recommendations?

On 8/22/2015 5:32 AM, Brent Hilpert wrote: On 2015-Aug-21, at 10:20 PM, Ali wrote: A brief conceptual overview: Vacuum-column and spring-arm drives comprise 3 servo systems: - each reel motor is in a closed servo loop with position sensors in its associated vacuum column or spring

RE: RM 380Z Special Control Unit (?)

SOME of the later S100 systems had regulated supplies and then ditched the board regulators, usually leaving a place to put a regulator with just a jumper wire in place of the regulator. tony duell a...@p850ug1.demon.co.uk wrote: ... Which also may well not be RML original. The 380Z has a

Re: diagnosing an Intel Series II MDS monitor failure

Sounds just like the supply on my Altos. What a pain. Eric Smith space...@gmail.com wrote: I previously wrote about the monitor of my Intel Series II MDS going out, which was because the +15V DC supply tripped the crowbar. The voltage adjust was all the way to the minimum, and the voltage was

RE: Microsoft multiuser Basic for the Altair 8800

-boun...@classiccmp.org] On Behalf Of Jay Jaeger Sent: Thursday, July 16, 2015 9:39 AM To: cctalk@classiccmp.org Subject: Re: Microsoft multiuser Basic for the Altair 8800 First of all, safety first when working around these power supplies. You have mains voltage exposed all over the place

Re: Reforming capacitors (technical description, not politics)

Better explanation than mine. Eric Smith space...@gmail.com wrote: Some people seem to think that reforming an aluminum electrolytic capacitor is some kind of cheat, akin to zapping NiCd cells or rejuvenating CRTs. Actually reforming is the same electrochemical process that the manufacturer uses

Re: Booting an IBM MP 3000 S/390 System

Until that console processor fails with no backups. I seem to recall having 4 or 5 backups (aka operators). ;) On 8/6/2015 2:07 PM, Fred Cisin wrote: On Thu, 6 Aug 2015, Jay Jaeger wrote: Acch. All this modern/complicated stuff. Once you powered on an IBM 1410 (2 seconds), you could have

Re: Booting an IBM MP 3000 S/390 System

to spin up, which was about 10 seconds. The actual booting of the system is about 0.3 seconds. Add 5 seconds if you had to manually enter the bootstrap. Johnny On 2015-08-06 20:43, Jay Jaeger wrote: Acch. All this modern/complicated stuff. Once you powered on an IBM 1410 (2 seconds

Re: Booting an IBM MP 3000 S/390 System

blaming the console processor which was not the problem. Turned out to be a recently added power supply - which I had pointed out to them was something that changed, and something we could do without as a test. Sigh. On 8/6/2015 7:13 PM, Jon Elson wrote: On 08/06/2015 04:01 PM, Jay Jaeger wrote

Re: OT: Slow booting, was re: Booting an IBM MP 3000 S/390 System

Aside from memory tests, in my experience, sometimes slowness can be caused by a disk controller ROM (often on a SCSI controller) that gets invoked during the POST that slows things down - particularly if it also enumerates what is on the SCSI bus. On 8/6/2015 7:35 PM, Chuck Guzis wrote: On the

Re: Wanted: Pertec Tape Controller

I would love to see that Verilog, as I have a Digilent Nexys2 (Xilinx Spartan 3E) and a Pertec drive I could play with. On 8/6/2015 11:19 AM, Chuck Guzis wrote: On 08/06/2015 08:35 AM, Al Kossow wrote: Formatted Pertec is a fairly simple interface. Chuck has talked in the past of designing

Re: Booting an IBM MP 3000 S/390 System

Backing up your console: Clonezilla is your friend. On 8/6/2015 10:54 PM, Guy Sotomayor wrote: I *really* have to figure out a backup solution for this so that I don't get stuck but that supposes that I have a way to re-create the OS/2 image that's already there if I do have to do a full

Re: More DEC boards

On Wed, Aug 12, 2015 at 11:58 PM, jwsmobile j...@jwsss.com wrote: On 8/12/2015 8:26 PM, Paul Anderson wrote: Thanks Jay, I was afraid i messed in up On Wed, Aug 12, 2015 at 10:25 PM, Jay Jaeger cu...@charter.net wrote: When I visited this link, I ended up with a blank, white page

Re: SCSI Tape to TAP utility

=0B2v4WRwISEQRfi1TWnlKU1hqUXphWVhpZ1FKOGFoVjRPVnppX1F2aUMwTUw0QkxSNEsyMjgusp=sharing They are anything but elegant, but have gotten the job done for me. JRU On 8/9/2015 11:57 PM, Marc Verdiell wrote: Hey, I'll take the offer, I am interested in both. Marc Jay Jaeger wrote: If anyone

Re: SCSI Tape to TAP utility

On 8/9/2015 12:36 PM, Chuck Guzis wrote: Good OS-es allowed an operator to mount tapes for his next few jobs, without paying attention to paper labels and have the OS automatically locate and assign tapes to the proper job. Can UNIX do that? --Chuck Seems dangerous to me: duplicate

Re: Apollo DN series HP root account

Hmmm. Not that I recall. Seems to me that one could boot with the boot switch in service mode (so it doesn't boot right through to DOMAIN/OS, though, and you could get a shell, allowing one to use a command-line editor to edit out the offending password. If you are still stuck in a couple of

Re: SCSI Tape to TAP utility

Glad to help. On 8/10/2015 6:14 PM, Rich Alderson wrote: From: Jay Jaeger Sent: Monday, August 10, 2015 8:56 AM The link below is to a Google Drive folder with three files that I will leave up for a while: awstape.c - Read a SCSI tape, output in AWS format (Linux) awstoraw.c - Read

Re: Shugart 800-8 media centering problem

On 8/14/2015 2:01 PM, Fred Cisin wrote: On Fri, 14 Aug 2015, Jay Jaeger wrote: I have a Shugart 800-8 with a media centering problem. I know it is definitely that and not something else (say, electronics, TRK00 position, etc.), because I can see the wobble in the signal coming from

Shugart 800-8 media centering problem

I have a Shugart 800-8 with a media centering problem. I know it is definitely that and not something else (say, electronics, TRK00 position, etc.), because I can see the wobble in the signal coming from the heads on a 'scope. Depending on how I load the floppy, the attenuation can be from

Re: Shugart 800-8 media centering problem

On 8/15/2015 11:51 AM, tony duell wrote: In every 8 (and 5.25) drive that I've seen the spindle (the bit driven, maybe indirectly, by the motor) has a female cone on the end. There is then the clamping cone, often plastic which fits into it through the hole in the disk. Not so on these

Re: Shugart 800-8 media centering problem

On 8/15/2015 1:35 PM, tony duell wrote: Not so on these drives. On the Shugart SA-800 series, the spindle (driven by a belt from a motor) has a MALE cone on the end, and the clamp, from above goes around it (female if you like). I have just pulled the case on one of my HP9885s, which

Re: Shugart 800-8 media centering problem

On 8/14/2015 11:56 PM, tony duell wrote: There is no play in the spindle at all. Certainly not 1/2 track worth. Can't wiggle it at all, no visible wobble, etc. Not necessarily play. Anyway, half a track width is just over 10 thou and I am not sure I could notice that amount of runout by

Re: Shugart 800-8 media centering problem

Certainly this thing is old enough. But I don't see how it would ever work if that were the case. When the media is on center, it works flawlessly, including interchange with another drive. One thing I am going to try today is to manually center the media with the AC power disconnected (not

Re: Shugart 800-8 media centering problem

On 8/14/2015 11:56 PM, tony duell wrote: There is no play in the spindle at all. Certainly not 1/2 track worth. Can't wiggle it at all, no visible wobble, etc. Not necessarily play. Anyway, half a track width is just over 10 thou and I am not sure I could notice that amount of runout by

Re: Writing 8 floppies with SuperCard Pro

the controller to change the timing of the write pulses. The correspondent should probably check with the SuperCard Pro folks to make sure BOTH have been implemented. It is quite possible neither have. On 8/12/2015 4:05 AM, Christian Corti wrote: On Tue, 11 Aug 2015, Jay Jaeger wrote: Aside from

Re: Classic programming

On 8/8/2015 5:47 PM, Chuck Guzis wrote: On 08/08/2015 12:13 PM, Jay Jaeger wrote: I have always felt that the language name is SNOBOL, with multiple versions, kind of like FORTRAN II (which is what the 1410 had), FORTRAN IV, FORTRAN V, etc., but Griswold seems to think otherwise. ;) I

Re: SCSI Tape to TAP utility

If anyone is interested, I have code for a Linux SCSI tape to AWSTAPE program, and a program that translates aws format to a raw byte stream. Not sure if I have one that translates to the SimH .tap format, though. GNU C. JRJ On 8/8/2015 7:57 PM, Chuck Guzis wrote: A couple of weeks ago, I

Re: Booting an IBM MP 3000 S/390 System

Lots of machines have had console processors that were required for the machine to run. The PDP-10 had a PDP-11 console processor. The Amdahl 470 had a DG Nova for a console processor, etc. etc. On 8/6/2015 8:16 AM, geneb wrote: On Thu, 6 Aug 2015, Marc Verdiell wrote: Wow. I'll never

Re: Wanted: Pertec Tape Controller

I wouldn't mind one as well -- I have a handful of Pertec drives that it would be nice to be able to talk to. One that handles multiple interface speeds would be a plus. I suppose I could always design one ;) On 8/6/2015 8:49 AM, Tom Moss wrote: Hi all, I'm looking for a pertec

Re: Mysterious S100 SRAM card

That does sound like a MITS serial no. The K is for Kit as opposed to factory assembled. drlegendre . drlegen...@gmail.com wrote: What's the significance of 3462K, as is hand-written on the 8080 CPU board? Is that a serial? On Sat, Jul 25, 2015 at 1:29 PM, Brent Hilpert hilp...@cs.ubc.ca

Re: IBM RT memory boards

I have an RT and may be interested. Mike Stein mhs.st...@gmail.com wrote: I've got 4 4Mx32 memory boards here from an old RT (AFAIR) in case anybody has a use for them. Each board has 8 512Kx40 (32 bits + 8 ECC) modules (20 pcs. 4x256). Edge connector is DS 42+49 m

Re: using new technology on old machines. Was: PDP-12 Restoration at the RICM

Not all EE's have the same education with regard to how semiconductors function. When I was in school I took a class in semiconductor physics - an entire semester on how the wee beasties function - more than most EEs. The prof., Henry Guckel, told an interesting story about an advanced IBM

Re: Reproducing old machines with newer technology (Re: PDP-12 at the RICM)

Discussion: On-Topic Posts Subject: Re: Reproducing old machines with newer technology (Re: PDP-12 at the RICM) On Jul 13, 2015, at 8:35 AM, Jay Jaeger cu...@charter.net wrote: Another alternative would be to build a machine up from a Field Programmable Gate Array (e.g., the Digilent Nexys2 FPGA

Re: Reproducing old machines with newer technology (Re: PDP-12 at the RICM)

This brings up a good point: just because a D Flip Flop is clocked by something other than a system-wide (or subsystem-wide) clock does not turn it into a latch. Flip flops can clocked by combinatorial inputs. This can be a problematic thing of course, as they can cause glitch problems - had a

Re: Reproducing old machines with newer technology (Re: PDP-12 at the RICM)

the tapes *analog* using a 7 track drive, and then post-processes the results to de-skew and recover the data. JRJ On 7/15/2015 7:12 PM, Chuck Guzis wrote: On 07/15/2015 04:05 PM, Jay Jaeger wrote: Paul adapted PUFFT (Purdue University Fast FORTRAN Translator) to do RS-232 bit serial I/O through

Re: Microsoft multiuser Basic for the Altair 8800

First of all, safety first when working around these power supplies. You have mains voltage exposed all over the place, including the front panel switch. What I typically do is take it all the boards out and disconnect the power supply, and pull it out. I then re-form the capacitors by taking

Re: Reproducing old machines with newer technology (Re: PDP-12 at the RICM)

On 7/14/2015 11:27 AM, Paul Koning wrote: On Jul 14, 2015, at 11:46 AM, Jay Jaeger cu...@charter.net wrote: ... Using the structural / gate level techniques, one does run into some issues, most of which have (or will probably have) solutions: 1) R/S latches composed of gates

Re: Reproducing old machines with newer technology (Re: PDP-12 at the RICM)

On 7/14/2015 11:16 AM, ben wrote: Here is the link you have been waiting for, IBM 1130 in FPGA and in the FLESH. http://ibm1130.blogspot.ca/ Ben. Thanks for that link. It looks very interesting after a quick glance. I am sure that I will run into many of the same issues with the SMS

Re: Reproducing old machines with newer technology

Almost sounds like the CPU was kind of an attached processor - similar to the way vector processors have been implemented by IBM and others. On 7/14/2015 5:28 PM, Chuck Guzis wrote: On 07/14/2015 02:53 PM, William Donzelli wrote: Again, you're missing the point. This was a fairly specific CDC

Re: Reproducing old machines with newer technology (Re: PDP-12 at the RICM)

The 12-bit computer that I translated originally had *independent* 1 micro-second clocks in each of four racks. The processor derived a 3 micro-second clock from that, but also a second clock that was out of phase with the CPU master clock, used to sync. signals coming in from the other racks

Re: Reproducing old machines with newer technology

I wonder if there is anywhere near enough information available to do a Stretch. JRJ On 7/14/2015 6:53 AM, Noel Chiappa wrote: From: Jay Jaeger I am going to attempt to do the same for IBM's 1410 computer - a really big effort. Now, the IBM machine you (or someone) should

Re: Reproducing old machines with newer technology (Re: PDP-12 at the RICM)

Sometimes it is fun to be a relative expert on an obscure branch of knowledge that few people are even aware of. I worked on one when I was a student, as an operator, programmer and systems programmer. Tweaked its FORTRAN compiler to spit out text error messages instead of just error codes. The

Re: Reproducing old machines with newer technology (Re: PDP-12 at the RICM)

Guzis wrote: On 07/14/2015 04:49 PM, Jay Jaeger wrote: Not necessarily. For example, it is impossible to find an IBM 1410, as far as I know. But there ARE 1415 consoles I knew of a while back, and there are certainly 729s and 1403 printers and 1402 card read/punch units up and running

Re: Reproducing old machines with newer technology (Re: PDP-12 at the RICM)

1410 - reproduce the actual machine logic. Compare/contrast what you referred to to the documents at: http://bitsavers.informatik.uni-stuttgart.de/pdf/ibm/1410/drawings/ On 7/15/2015 12:10 AM, Chuck Guzis wrote: On 07/14/2015 09:16 PM, Jay Jaeger wrote: Other than clones and the like (e.g

Re: Reproducing old machines with newer technology (Re: PDP-12 at the RICM)

I remember when U Wisconsin ECE got their PDP-11/20 and I saw DOS FORTRAN get stuck for the very first time. I told the more senior student who was responsible for getting things going, preparing documentation, etc. that the machine was in a loop, and never coming out. He laughed at me, claiming

Re: Time to dig out some of my DEC XX2247 keys

Holy cow. On 7/15/2015 3:49 PM, Al Kossow wrote: http://www.ebay.com/itm/281749697289

Re: Reproducing old machines with newer technology (Re: PDP-12 at the RICM)

1440s and 1460s were architecturally 1401s (much as the 7010 is architecturally a 1410 - software compatible). I have not heard of a 1450 anywhere, but seem to recall hearing about at least one 1460 and see photos of them online. On 7/15/2015 12:26 AM, William Donzelli wrote: In the 7000

Re: Reproducing old machines with newer technology (Re: PDP-12 at the RICM)

conserving memory. On 7/15/2015 1:14 PM, Chuck Guzis wrote: On 07/15/2015 10:48 AM, Jay Jaeger wrote: Lots of machines supported variable length operands (like the machine you reference in the link, IBM S/360, Burroughs, etc. etc. However, machines with variable length instructions not split into any

Re: Reproducing old machines with newer technology (Re: PDP-12 at the RICM)

of variable length. Again, while that was true from the perspective of variable length data fields, it wasn't from the perspective of variable length instructions. On 7/15/2015 2:42 PM, Chuck Guzis wrote: On 07/15/2015 11:29 AM, Jay Jaeger wrote: Sigh. Again, the difference is between how OPERANDS

ALTOS 8000-2 Boot ROM Questions

OK, so I got my nice shiny Z80-A CTC chip in the mail today, stuck it into the ALTOS, and I now get the expected % prompt. So, one problem fixed. So, not having a real floppy with the diagnostics or CP/M image on it, I ran the Single Sided, Single Density diagnostic image on

Re: PDP 11 gear finally moved

It is generally a good idea to re-form electrolytic capacitors in power supplies, and to bench check the power supplies (under some kind of load) before actually applying power to the whole unit. JRJ On 7/17/2015 11:49 AM, devin davison wrote: Devin here, I had asked for advice on how to move a

Re: PDP 11 gear finally moved

What I am wondering about, though, is the extra current they draw while they are forming up while the power supply is running. The capacitor might survive it (not get so hot that it fails), but the things supply the higher than ordinary current to it might not. Killed a bridge rectifier on a

Re: PDP 11 gear finally moved

That might be a little different -- much more recent - presumably in the ear of flat screens and PCs where there have been times when manufacturers got fed bad capacitors for their boards - which then failed later. IBM replaced a whole series of motherboards in one organization that I worked at

Re: PDP 11 gear finally moved

I tend to agree with your hunch. On 7/17/2015 1:55 PM, Todd Killingsworth wrote: I suspect part of the swap'em ALL out mentality comes from the 90's when some botched industrial espionage had some of the bottom-tier cap manufacturers using a dodgy electrolytic formula for their caps. These

Re: PDP 11 gear finally moved

U - his PDP-11/34 most certainly does use switching power regulators. ;) On 7/17/2015 4:06 PM, John Robertson wrote: On 07/17/2015 11:53 AM, Mouse wrote: I do find this witch-hunt against capacitors to be curious, given how few I've found to have failed. I suspect a lot of it comes from

Re: PDP 11 gear finally moved

Replace - no, I don't agree - especially not for those of us who don't have the kind of budget that your organization has. In my experience, for equipment of this quality and vintage, 95% or more of the time an hour to a few hours of re-forming is all that is necessary - and as Tony has pointed

Re: PDP 11 gear finally moved

. Of course reforming a bad capacitor, whatever the failure mode, is going to be useless. Tothwolf tothw...@concentric.net wrote: On Fri, 17 Jul 2015, Jay Jaeger wrote: On 7/17/2015 1:33 PM, Rich Alderson wrote: It is generally a good idea to re-form electrolytic capacitors in power supplies

Re: Reproducing old machines with newer technology (Re: PDP-12 at the RICM)

/2015 10:10 PM, Chuck Guzis wrote: On 07/14/2015 06:55 PM, Jay Jaeger wrote: Architecturally, it was pretty much the last of its kind: the last of the BCD decimal arithmetic machines, which also makes it interesting. It has also become much more obscure than the 1401, which it followed

Re: Speaking of reproductions..

On 10/24/2015 2:21 AM, Brad wrote: > I was checking out the Altair 8800 kit online (really cool). But I am > hoping to one day find a kit or plans to build a Mark-8 replica, since I'm > so deep into Radio Electronics features. I know there was a kit out there > (Obtronix?). Was it any good? Do

RF08/RS08 photos and panel measurements (Re: RK11-C Panel)

Looking at the document at: http://dustyoldcomputers.com/pdp-common/reference/drawings/peripherals/docs/DEC-08-HIEA-DA_RF08_Jun70.pdf The picture, though extremely fuzzy, matches my panel in the organization of legends and breaks in line. Since I have what I think is a complete RF08, and pieces

Re: Retro Reproduction 2

On 10/23/2015 6:43 PM, Mike Ross wrote: > 1. A replacement perspex for a pdp-12; damaged in shipping :-( If you mean the plexiglass for the console, I might be able to help with that. I thought at one point I was going to get an entire PDP-12 from U. Wisconsin Comm. Arts, but when I showed up

Re: Retro Reproduction 2

On 10/23/2015 10:37 PM, Jay Jaeger wrote: > On 10/23/2015 6:43 PM, Mike Ross wrote: > >> 1. A replacement perspex for a pdp-12; damaged in shipping :-( > > If you mean the plexiglass for the console, I might be able to help with > that. I thought at one point I was going to

Re: The Internet & our hobby

On 10/22/2015 7:54 PM, Murray McCullough wrote: > 43 years ago around this time the Internet we use to communicate with > was probably made possible because of TCP/IP, or Transmission Control > Protocol/Internet Protocol created at Stanford University. Today 3 > billion people are on the net but

Re: The Internet & our hobby

On 10/23/2015 3:29 PM, Ethan Dicks wrote: > On Fri, 23 Oct 2015, Bill Sudbrink wrote: > > I'd expect wide-eyed stares from a vi user... ;-) > > > Q: What goes "beep beep beep"? > > A: A Little Nash Rambler... and a vi novice. > > -ethan > ROTFL. JRJ

MAINDEC-11-DZQKC-E-D listing posted (Re: Deciphering PDP-11/05 ZQKC (Instruction Exerciser) MAINDEC failures...)

On 11/9/2015 3:42 PM, Josh Dersch wrote: > On Mon, Nov 9, 2015 at 12:37 PM, Jay Jaeger <cu...@charter.net> wrote: > >> On 11/8/2015 11:50 AM, Josh Dersch wrote: >> >>> >>> Anyone have any experience with this particular diagnostic? >>> >

Re: Todays Topic from Panelman

On 11/17/2015 2:34 AM, rod wrote: > > Now to the slide switches themselves. > > They are mounted by the screw hole lugs having been slid into a groove > in two aluminum bars which in turn are attached to the PCB by pillars > and screws. > There are six connection pins on the bottom of each

Re: IBM z890

On 11/2/2015 9:15 PM, Mike Ross wrote: > On Tue, Nov 3, 2015 at 4:03 PM, Connor Krukosky > wrote: >> I recently won an IBM z890 via auction for $237. > > Congratulations! Mainframes are fun! > >> It was a very interesting adventure to retrieve this machine since it

Re: Micro-Altair tape interface

On 11/2/2015 11:54 PM, d...@661.org wrote: > > As I finally complete my Micro-Altair kit from Briel Computers, my > thoughts turn to the question of how I can get an audio tape interface > working on this machine. > > I understand that the MITS tape controller is essentially a serial port > with

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