[cctalk] Re: Z80 vs other microprocessors of the time.
On Mon, Apr 22, 2024 at 2:30 PM Paul Koning via cctalk wrote: > Anyway, I would think such a small microprocessor could emulate a PDP-11 just > fine, and probably fast enough. The issue isn't so much the instruction set > emulation but rather the electrical interface. That's what would be needed > to be a drop-in replacement. Ignoring the voltage levels, there's the matter > of implementing whatever the bus protocols are. Emulating an F-11 chip or a J-11 chip is certainly possible with a modern MCU, just need TTL-friendly I/O. F-11 is 40-pins (and can have additional instructions added by adding microcode ROMs next to the CPU) and the J-11 is 64 pins on a fat chip carrier. > Possibly an RP2040 (the engine in the Raspberry Pico) would serve for this, > with the PIO engines providing help with the low level signaling. Sounds > like a fun exercise for the student. Could be a good start but would still need level shifters. J-11 runs at 15-18Mhz for an idea on how fast the bus implementation has to be. -ethan
[cctalk] Re: PDP-11 thingy. What is it?
On Wed, Apr 10, 2024 at 8:07 PM W2HX via cctalk wrote: > 1. I have read that the card and the drives were compatible with the dec rx02 > drives. Why would the CRDS even bother to redesign a card where DEC had > perfectly good working ones? Anyone know if there is any value in keeping the > FC-202 or just keep with the DEC cards? The easy first answer is DEC's drives were expensive so there was room for competition to bring in a less expensive product and then _they_ would get the profits. The second answer is that DEC's implementation was basic - read and write single-sided floppies and that's it - no media (re)formatting. Third parties could add features to extend what DEC had. The DEC implementation relied on a custom processor board inside the disk drive and a unique/proprietary way to have the controller tell the drives what to do. By the late 80s. Shugart interface drives were plentiful and processors like the Z-80 were totally capable so there were several RX01 and RX02 imitators. I have at least one Qbus card that just has a Shugart interface and was connected to a standard floppy drive mechanism (and it can low-level format disks). In order to work with existing drivers, though, the third party cards did have to emulate them at the I/O register level but as long as it's registers on one end and 8" media on the other, they were free to reimplement the middle part. -ethan
[cctalk] Re: Drum memory on pdp11's? Wikipedia thinks so....
On Mon, Apr 15, 2024 at 12:53 AM Christopher Zach via cctalk wrote: > Was reading the Wikipedia article on Drum memories: > > https://en.wikipedia.org/wiki/Drum_memory#External_links > > And came across this tidbit. > > As late as 1980, PDP-11/45 machines using magnetic core main memory > and drums for swapping were still in use at many of the original UNIX > sites. > > Any thoughts on what they are talking about? I could see running the > RS03/RS04 on a 11/45 with the dual Unibus configured so the RS03's talk > to memory directly instead of the Unibus, but that's not quite the same > as true drum memory. Yep. > Closest thing I remember was the DF32 on a pdp8 which could be addressed > by word as opposed to track/sector. Yes. And the RF series (RF08 and RF11). UNIX on the PDP-11 in 1972 required an RF11 for swap. As mentioned in other replies, the media isn't cylindrical but it behaves logically like a drum. -ethan
[cctalk] Re: Voyager spacecraft computer
On Fri, Mar 15, 2024 at 6:49 PM Charles Dickman via cctalk wrote: > Voyager 1 is in the news recently because of communications problems and > possible solutions. Is there an online source for documentation on the > Voyager systems, especially the computers and navigation systems? > > I have enjoyed reviewing the Apollo systems documentation on the Virtual > AGS Home Page and wondered if there were similar documents available for > Voyager. "NASA Contractor Report 182505 Computers in Spaceflight: The NASA Experience" More of a top-level tour of a number of platforms, it covers, in quite some detail, systems from Gemini to the Space Shuttle and mentions the RCA 1802 numerous times. Samples of some NASA DSLs (HAL/S and GOAL). Extensive citations and bibilography. Voyager and Galileo are covered in Chapter 6. Public domain. PDF link at: https://ntrs.nasa.gov/citations/19880069935 Excellent stuff in there. -ethan
[cctalk] WTB: x68000 keyboard and mouse
USA here, anyone have a Sharp x68000 keyboard and mouse to sell? The one that I've repaired and am trying to complete is the desktop version, black, mini-din connector. -- : Ethan O'Toole
[cctalk] Re: VCF SoCal
I had someone very seriously questioning me, over on Fesse Bouc, if I was serious when I said that the ZX Spectrum could remotely be considered a more significant machine than (one model of) TRS-80, and he was incredulous when I absolutely maintained the point. We had the Timex version of the Spectrum in the USA, but it wasn't much of a machine. That probably ruined it so we never got the 2+ or 3+. Virginia USA reporting in, and so far I have the Spectrum 2+ (boxed) and 3+. They are cool machines but I think the Atari and Commodore beat it sound wise. But I *REALLY* dig the fact that you had cassette distribution of software at what looks like pretty low prices? That is really cool. I imagine game tapes in supermarket checkout lines everywhere. Remember when these machines were on the market in the 80s everyone relied on magazines for information, and those magazines relied on advertising dollars. No WWW. So it's not a big wonder that that Americans didn't know about these machines since marketing money wasn't spent here. Thanks to another cclist member I have purchased an A4000 Acorn via facebook marketplace, and am excited to finally get my first Archimedes machine. Hope the repairs needed aren't too bad! After that will be a BBC micro but really the A4000 seems like a killer machine. At some point I might try to find an A3010 as well, but the 4000 checks the boxes for me. It's pretty hard buying machines from over there, local collection only! - Ethan O'Toole
[cctalk] Re: Anyone have a D1 deck?
I have 3/4" unatic, svhs, super beta, DAT, minidv, digital 8, adat. never got into betacam, d1 or any of those monster formats as tape was expensive as a geek. The sony tape machines for the big digital pro formats are s beautiful though!!! At this point Im going to have to get the superbeta and svhs machines overhauled and fearing the cost. I've been really surprised how much news that made. I've seen it get asked a few times in a few retro places. I would think lots of tv stations, colleges, and audiophiles would have one but maybe it really is that obscure. Given, I've never heard of the format so maybe I'm being naive. On 12/30/23 22:26, Jim Brain via cctalk wrote: https://entertainment.slashdot.org/story/23/12/30/0151241/documentarians-secure-original-reboot-master-tapes-but-need-help-to-play-them -- : Ethan O'Toole
[cctalk] Re: programming the IBM PC synchronous serial boards (Northstar Advantage project)
On Fri, Dec 22, 2023 at 10:20 PM Chuck Guzis via cctalk wrote: > Sync (Bisync, SDLC/HDLC) was fairly popular back in the day for linking > with mainframes. (Think, for example, IBM HASP). On PCs and the like, > the Intel 8251 was used a lot, but even the Signetics 2651 has the sync > mode, with the ability to recognize a double-byte sync. The COMBOARD line of Bisync and SNA protocol engines came out of the HASPBOX product, which was 100% DEC hardware, so we started with a COM5025 (same as at least one of DEC's sync seral boards) and we later moved to the Zilog Z8530 (but only ever used its second port as a local async debug port) > The protocol for any of the above higher-level protocols is fairly > complex and there are manuals for that Yeah, implementing Bisync from scratch on a new platform would be quite an effort. There are a few poorly-documented "gotchas" to work through/around. -ethan
[cctalk] Re: Intel 4004
On Mon, Nov 27, 2023 at 5:32 PM Rick Bensene via cctalk wrote: > Steve Lewis wrote: > > then like the 4004, we're struggling to find evidence of actual products > > that > > made use of them. Wasn't the 4004 used in some cash registers, street > > lights, or > > some weighing machines? (I don't have any specific references, just > > recollections > from past reading) Over the years, I've found a 4004 in two commercial products - a 1970s non-UPC barcode scanner, and a commercial kitchen scale. I still have the PCBs for the scale (with the accessory chips). The barcode scanner was utterly dismantled 35 years ago. -ethan
[cctalk] Re: PDP11 and Ultrix 11
On Fri, Oct 20, 2023 at 1:46 PM Henry Bent wrote: > I have a SIMH installation of Ultrix-11 3.1 on RL02 drives. Two RL02s is > enough for a base system and four (which would be what the DQ614 provides, if > it worked) would be more than enough for sources and work, etc. Yes. 40MB should be plenty of room. 10MB was definitely not enough for 2.9BSD, but at the time, I only had one RL02 drive. > The Ultrix-11 RL driver does fancy things with overlapped seeks that I'm sure > works on real hardware but on the DQ614, not so much. Ah... I can see that. It wouldn't surprise me if the DQ614 got most of its development and testing with RT-11 in mind, and possibly some RSX-11. I remember that the DEC RL controller (at least for PDP-11, not as sure about the RL8A) did support some pretty handy things for a multi-user OS, like overlapping seek, but I think in all the years I worked with DEC gear, only a few machines had multiple RL drives. Mostly I saw them as data transfer devices or for primary storage on small (single-user) systems. We did have one larger system, an 11/24 with four RL02, running RSTS/E and whatever we were using for accounting software. I didn't work on the machine myself except to physically disconnect and pack and move it from one site to another when we consolidated our operations back into one building. -ethan
[cctalk] Re: PDP11 and Ultrix 11
On Wed, Oct 18, 2023 at 10:21 AM Henry Bent via cctalk wrote: > Interesting. My Dilog DQ614 (ST506 emulating RL02s) specifically does not > work with Ultrix, but does work with 2.xBSD and v7, so I would not > necessarily assume that a third-party board was going to work with > Ultrix-11's drivers. I have personally installed 2.9BSD on an 11/24 with RL11 and RL02 so I _know_ that works (and I would expect the DQ614 to work there too). I have a DQ614 but the Rodime drive that came with it was toast and I only recently got the RT11 utility to fiddle drives so I haven't ever tried to use mine. I may end up tossing an ST225 or ST241 on my DQ614 when I get around to trying it. I do not know what drives Ultrix-11 supports but it wouldn't be shocking to find that you can't use an RL02 as the root install device. An RL02 was only big enough for the base install of 2.9BSD and not big enough for base+sources so I was never able to rebuild my kernel (it all worked fine on an RK07 at work). In the past, I never did anything with 2.11BSD or Ultrix-11 because I didn't have a new enough setup (most of my gear came from the 70s and early 80s - no J-11 anywhere until recently). As mentioned, if it's a well-implemented MSCP SCSI controller (UC07, CQD220...), it should "just work" on any system there are MSCP drivers for. Cheers, -ethan
[cctalk] Re: 11/15, 11/20 systems and parts, more
On Fri, Oct 20, 2023 at 12:11 PM Jon Elson via cctalk wrote: > On 10/20/23 03:59, Michael Thompson via cctalk wrote: > > The RICM has an empty 11/20 chassis and the power supply. All it needs is > > the processor backplanes. Is there any chance you have a set of backplanes > > available? > > > I have a DD11-PK backplane (Part No. 70-11523) with a few > bent pins. None are bent so badly they can't be > straightened. From 11/04 or 11/34. Free if you pay shipping. DD11-PK is for 11/34 (top two slots for CPU). PDP-11/04 uses standard DD11-DK (single-board CPU, doesn't need special slots). The 11/20 is entirely different. It has three 4-slot backplanes for CPU boards with "random" wiring and Unibus out on AB of final slot. It would be unusual but not impossible to see the 11/20 CPU backplane assembly outside of a BA11-C cabinet. If one had 12 DEC backplane blocks, one could make a replacement but it would be quite an undertaking. Might be easier to make a PCB-based replacement with modern connectors. Could also upgrade power input scheme while at it. -ethan
[cctalk] Re: Tadpole/RDI UltraBooks - UNIX notebooks - species needs rescue...
Awesome! Didn't realize MAME ws limited to 32-Bit SPARC. But the emulators can definitely be handy, or at least get you partly there! - Ethan Hi Ethan, thanks for suggesting MAME - did some research and somehow I do not think it emulates UltraSparc but only 32bit Sarc. But saw, that QEMU has a UltraSparc emulation and they... https://www.qemu.org/docs/master/system/target-sparc64.html ...explicitly claim that a NVRAM is emulated, although they are doing a M48T59 there is at least some chance that the memory address can be found in the QEMU sources. Will take a look in the next weeks ;-) -- : Ethan O'Toole
[cctalk] Re: Tadpole/RDI UltraBooks - UNIX notebooks - species needs rescue...
Interesting - did you youse some modern technology for doing that? I already thought to attach a logic analyzer to the NVRAM to see which bytes are read first (e.g. for dtermining the hardware configuration). Late to the convo, but it's interesting. You might be able to dump the ROMs and find someone who knows Sparc assembly to run it through a debugger/emulator and trace it? Hard part would probably be knowing where the NVRAM lives in memory space (memory map.) Maybe the MAME people would have an idea? Some of the old arcade games suffer from the exact same issue - they store variables in the ST Microelectronics Timekeepers and once it dies game won't boot due to a byte or two. MAME has SPARC emulation. Other thing is people with a working Tadpoles needs to dump their NVRAMS ASAP because it sounds like all of them are about to quit working? -- : Ethan O'Toole
[cctalk] Re: Any leads on Fairlight sampler that needs repair?
That's why I said broken! A boy can dream! - Ethan They are a fairly high demand item when they come up for sale, and are very expensive. Sellam
[cctalk] Any leads on Fairlight sampler that needs repair?
Anyone have any leads in USA on a Fairlight CMI or similar that needs repair? S-100 based sampler from the 80s. Would be fun to restore one. - Ethan
[cctalk] Anyone in Sheffield uk?
Anyone in Sheffield UK? There is an Acorn Archemedies computer I am interested in buying but the guy is collection only. I am in the USA, but interested in buying and repairing the system. - Ethan
[cctalk] Re: PDP-8/L $15,000
I hate what epay is doing to our hobby.
I prefer to sell and trade between our selves as reasonable prices
understanding that a lot of what we do is sweat equity.
If you think the hobby is bad, you should see what happened to housing.
"I know what I got!"
I have a lot of different geeky hobbies and what happened to vintage
computing is idential to what happened to video games (way bigger market)
and music equipment (Synths, guitar stuff.) Same with aracade games and
especially pinball machines. What was a $1000 C title pinball is now $5000
with some gaudy mods taped to them.
I could the be the eternal pessimist, but I think things are weakening? I
have some synthesizers I rebuilt up for sale and notice the market is much
slower than it was. I wish I could get a read on the video game markets
which of course spill into some classic computers. I assume people are
going to pull back spending at some point, but with 40% more money added
to the US economy in the last few years there are people sitting on a
lt of cash. Be it stock wins or PPP loan freebies or crypto or
hoomer gains.
If it could only dip on the stuff I want but rise on the stuff I have.
- Ethan
[cctalk] Re: PDP-8/L $15,000
However, epay does charge an insertion fee so they will have to pay even when it doesn't sell. Eh, you get a lot of free listings these days. They take a huge chunk though. - Ethan
[cctalk] Re: Apple 1
On Thu, Aug 17, 2023 at 2:34 PM Bill Degnan via cctalk wrote: > On Thu, Aug 17, 2023 at 2:28 PM Ethan Dicks via cctalk < > I should add that part of the fun is to locate parts for free or cheap from > dead or unimportant period electronics, cards, etc. In that way slowly > building up what is needed to complete parts of the Apple I replica one > piece at a time. I am not in a rush. I am totally doing that, but outside of early-70s dumb terminals and maybe some early electronic sound effect devices, there aren't a lot of places to encounter massive PMOS shift registers. RAM and generic logic are easy enough to find with patience. Closed TI sockets are also findable, but they were awful then and haven't improved one bit with age. -ethan
[cctalk] Re: Apple 1
On Sat, Aug 5, 2023 at 6:11 PM Cameron Kaiser via cctalk wrote: > I have an IMSAI as well, but for me my favourite computer of that era is the > KIM-1, and that's such a simple design there are tons of implementations I only recently got a KIM-1 (at VCF East). It's been on my list for a while and I was able to get it in a swap not eBay prices so I'm twice as happy. > (though I prefer the original since some of them apparently have edge-case > incompatibilities). I've had a replica for a while and for running code it's an adequate match, but, yes, there are some quirks that do matter. One of the biggest implementation differences from 1976 to today totally matters to me - I have an old TVT 6-5/8 Cheap Video board I got as a kid that needs the "upstream tap" to present different memory contents to the CPU and to the video board, and that in turn depends on how and where the bus is buffered. Most of the simple replicas are either total hardware emulation (KIM Uno) or are so small that they just don't have the same bus buffer arrangement so that would have to be hacked in. Now that I _have_ a KIM-1, I can look at how bad the hackery is and finally see this board in action. -ethan
[cctalk] Re: Apple 1
On Sat, Aug 5, 2023 at 4:08 PM Bill Degnan via cctalk wrote: > But...because the apple I is so valuable people have been motivated to > produce really nice replica motherboards. The replicas give many the > chance to experience the Apple I at a reasonable price I have a bare replica PCB. It's proving difficult to stuff without spending a wad. > It's fun to find original parts and sockets to try to get > a replica as close as possible to an original. You can do that for less than buying an original but it's still $$$ in part because of the rarity of the oddball shift registers, etc., and in part because of the demand for specific package types and date codes to achieve the closest match to an original. Just the ICs alone are hundreds of dollars, the large caps are tens of dollars and even that exact heat sink isn't exactly cheap. My classic interests are wide and varied (as demonstrated by what I bring to VCF) and totally encompass all sorts of 6502 systems. The specific interest the Apple 1 has for me is how screwy the video implementation is (cheap in its time but an evolutionary dead end) and how much it can do with 256 bytes of ROM and 8K of RAM. I would like to be able to build up my board just to watch it run, but outside of that, a non-exact replica (typically using a modern microcontroller to implement the stages of shift registers) still gets the job done for hacking raw 6502 code. I certainly believe in running old systems (I use machines from the 60s and 70s all the time) but in the case of a computer that costs more than my house, I'd probably lock it up in a vault and only take it out for special occasions too. -ethan
[cctalk] Re: Old Professional/350 software, any of this out there
On Thu, Jul 27, 2023 at 11:28 AM Mattis Lind via cctalk wrote: > Perhaps it would be a good idea to upload de-interleaved images along with > the .IMD, .DSK and a quick document that explains the situation. Otherwise > we will have this coming up every now and then and people will scratch > their heads until Paul explains the details. I concur. I have had this exact topic come up multiple times over the past 18 months. It's "documented" but not so plainly that most new users will ever find it. Mostly I hear "I converted IMD files to BIN but Simh can't mount them", over and over. -ethan
[cctalk] Re: Death of Mitnick
Too bad, but on the other hand, John Draper turned 80 this year. Probably a better role model. --Chuck Hah! Funny! - Ethan
[cctalk] Re: VCF and System Source Computer Museum swap meet this weekend
I'll be there. Hello Ethan. Bring some good stuff for me to buy. jk. -andy Years ago there was an auction of an Internet Kiosk company in Newport News Virginia. I decided to go. It was well advertised and run by a big company (probably Rasmus but I don't remember.) I get there. The crowd seemed to be a random bunch but it was well attended. Crowd was a mix of the flipper types, estate sales types maybe and a few geeks. I run into some people I knew from the BBS scene in my childhood. They could be troublemakers, but they tended to be funny. You know the type. We had separated ways years before and ran in different geek circles, but here they were. Kind of good seeing them again, but also obvious not much had changed. They were running a computer repair store, and purchased things like the filing cabinet full of customer records so they could market to them. They left test copies on all the copiers of ads for their adult website(s). I remember the auctioneer picking up the face down full coverage 8x11 paper ads in the output tray a little shocked on the mic "Looks like it works well..." Well one guy bids on this maxwell house can of screws. The hex head things that hold on the covers to your standard beige PC and the smaller ones that hold in the CD-ROMs and floppies. But not the hard drives, those use the case sized ones. Sold for $20 or whatever it was. I mean, it was pretty full but I thought it was a strange purchase. Some loud lady proclaims "Who on earth would pay $20 for a can of screws?" Everyone is watching, Geoff just shrugs. Doesn't say anything. She bids on this beige tower PC. Wins. Goes to pick it up and the cover slides right off. A lot of people see this. Kind of mortified she looks over at Geoff who is sitting on some furniture running his fingers through his $20 can of screws. He loudly says "Hey, I've got screws for sale a dollar each" once she looks over. Some are amused some confused. The auctioneer chuckles.
[cctalk] Re: VCF and System Source Computer Museum swap meet this weekend
Hi,
I am curious if anyone here might be planning on attending.
https://museum.syssrc.com/artifact/events/3000/
I am heading up there with friends Friday night so we can get there early
Saturday.
Bringing some stuff to sell, nothing too crazy just odds and ends. PICMG
Pentium rackmount machine and odds and ends for micros.
Only system on my "to get" list is Acorn Archemedies.
Looking forward to it, and I think System Source might be the #1
collection in the world. Very cool place.
Say hi if you see me and are on this list.
- Ethan
--
: Ethan O'Toole
[cctalk] Re: Restoring Ultrix-32m 1.2 Floppies
On Mon, Jul 17, 2023 at 1:05 PM Paul Koning via cctalk
wrote:
> > On Jul 17, 2023, at 12:51 PM, Ethan Dicks via cctalk
> > wrote:
> >
> > On Mon, Jul 17, 2023 at 12:48 PM Ethan Dicks wrote:
> >> From: http://www.chdickman.com/pdp11/pro380.txt
> >>
> >> "The RX50 floppy starts at track 1. Track 0 is logically placed after
> >> track 79. The sectors are...
> >
> > It should be "... interleaved 1, 3, 5, 7, 9, 0, 2, 4, 6, 8..." There
> > is no "sector 10" when counting from 0.
> >
> > -ethan
>
> I don't know what to make of that web page's description, it certainly
> doesn't have much connection to reality. Are those numbers supposed to
> represent the placement of logical sector numbers onto the physical track?
> If so, they show 5:1 interleave rather than 2:1 interleave. Or do they
> represent the physical sector numbers for consecutive logical sectors? If
> so, it seems to be backwards.
It looks like it represents how to go from a physical track to get
things back in the logical order that one would see from a PDP-11 or
VAX on real hardware - i.e., the boot block (if any) is the very first
thing you encounter.
I agree, it's not a 2:1 interleave in any classic sense.
> The actual algorithm is what I wrote in my previous email, which you can also
> find in my RSTSFLX tools. That has been tested against real world RX50
> floppies, and against the source code of the RT11 RX50 driver.
Chuck Dickman's algorithm is in lbn2rx50.c
#define RX50_TRACKS 80
#define RX50_SECTORS 10
int interleave[] = { 0, 2, 4, 6, 8, 1, 3, 5, 7, 9 };
track = lbn/RX50_SECTORS;
track = (track + 1)%RX50_TRACKS;
sector = lbn%RX50_SECTORS;
sector = (interleave[sector] + 2*(track - 1) + RX50_SECTORS)%RX50_SECTORS;
-ethan
[cctalk] Re: Restoring Ultrix-32m 1.2 Floppies
On Mon, Jul 17, 2023 at 12:48 PM Ethan Dicks wrote: > On Mon, Jul 17, 2023 at 12:28 PM Henry Bent via cctalk > > I'm almost thoroughly unfamiliar with IMD - is there some obvious > > extraction/conversion option that I am missing here? As mentioned previously, yes. There's an additional step that has to happen to any direct imaging of RX50 disks. John Wilson's PUTR happens to do this convolution internally. If you desire is to snapshot physical media for rewriting later, IMD is excellent. If you want logical-block-order files for simh, you need one more step (keep reading). > Were these disks actually imaged correctly? I would appreciate any > suggestions. Yes they were. > From: http://www.chdickman.com/pdp11/pro380.txt > > "The RX50 floppy starts at track 1. Track 0 is logically placed after > track 79. The sectors are interleaved 1, 3, 5, 7, 9, 0, 2, 4, 6, 8, > 10. The track shift and interleave must be taken into account when > moving disks between real PDP-11 and emulators." I have had good luck with a secfor convolver from the same page as this comment: http://www.chdickman.com/pdp11/lbn2rx50.c It will go both ways, to and from physical block order and logical block order. Cheers, -ethan
[cctalk] Re: Restoring Ultrix-32m 1.2 Floppies
On Mon, Jul 17, 2023 at 12:48 PM Ethan Dicks wrote: > From: http://www.chdickman.com/pdp11/pro380.txt > > "The RX50 floppy starts at track 1. Track 0 is logically placed after > track 79. The sectors are interleaved 1, 3, 5, 7, 9, 0, 2, 4, 6, 8, > 10. The track shift and interleave must be taken into account when > moving disks between real PDP-11 and emulators." Let me point out that this webpage quote accidentally lists too many sectors for an RX50. It should be "... interleaved 1, 3, 5, 7, 9, 0, 2, 4, 6, 8..." There is no "sector 10" when counting from 0. -ethan
[cctalk] Re: Restoring Ultrix-32m 1.2 Floppies
On Mon, Jul 17, 2023 at 12:28 PM Henry Bent via cctalk wrote: > I just noticed that images of a full RX50 floppy set for Ultrix-32m 1.2 was > posted on Bitsavers ( > http://bitsavers.trailing-edge.com/bits/DEC/vax/ultrix/1.2/ULTRIX-32M_V1.2_RX50_1986.zip > ). I am having difficulty parsing these images into a usable raw format > for SIMH. You are not the first to encounter this. > Oddly though, in the "raw" dump the bootloader doesn't > start until 0x1400, and a number of the other disks I looked at appear to > have odd holes/zeroes in them. IMD format dumps of the 1.2 disks are > provided but when I converted the IMD format to a raw image I got the same > issue. Yes. IMD->raw just decompresses the IMD format back into the exact number of bytes, in the same order, of the original media. Keep reading for why this is not sufficient... > I'm almost thoroughly unfamiliar with IMD - is there some obvious > extraction/conversion option that I am missing here? Were these disks > actually imaged correctly? I would appreciate any suggestions. This is not an IMD issue. IMD files are numbered as they come off the media and can be written back out, as is, to make physical media, which was the primary purpose. For nearly all cases, this also happens to match sequential sector order so that the same data can be used for emulators (simh and others). The one case where the two situations don't match is the RX50. What DEC did was to put a software-defined sector interleave and track shifting into their RX50 controllers (RQDX1 et al). In addition to the sectors on the disk not being in "logical filesystem order", track 0 gets moved to the end of the list From: http://www.chdickman.com/pdp11/pro380.txt "The RX50 floppy starts at track 1. Track 0 is logically placed after track 79. The sectors are interleaved 1, 3, 5, 7, 9, 0, 2, 4, 6, 8, 10. The track shift and interleave must be taken into account when moving disks between real PDP-11 and emulators."
[cctalk] Re: Don Lancaster has passed away at 83
On Thu, Jul 6, 2023 at 6:26 PM Bill Degnan via cctalk wrote: > I am going throw out a Jim Butterfield too I never got to meet him or correspond with him directly, but through his articles and his work with TORPUG, he absolutely had a huge indirect influence on my early years. I did learn plenty from Don Lancaster too, but it was more general knowledge than anything. I don't think I ever read something of his that I didn't learn something from. -ethan
[cctalk] Re: Bob Applegate passed away
On Sun, Jun 18, 2023 at 7:56 PM Cameron Kaiser via cctalk wrote: > > Just letting everyone know that Bob Applegate passed away a few days ago. > > He had been battling cancer for some time. He was involved with vintage > > computing for some time. Here is his website: http://www.corshamtech.com/ > > > > This is the website for his memorial: > > https://everloved.com/life-of/robert-applegate/ > > Bob made great stuff. I bought a few KIM boards off him a few weeks back. He > said the treatment wasn't going well, and it didn't seem like it would be > long. Yeah. I saw his update from Memorial Day weekend where he said he wasn't feeling well. On top of everything else, sounded like it was close, and it was. Since I got a KIM-1 at VCF East and since Bob wasn't there, I made a point of ordering some accessories from Bob back in April. Doubly glad I did. > I'm glad he's at peace. Indeed. -ethan
[cctalk] Re: Did Bill Gates Really Say That?
On Fri, Jun 16, 2023 at 10:26 PM Tomasz Rola via cctalk wrote: > I guess we are all prisoners of our own mental frame. I recall that > Ken Olsen (DEC founder), once quipped "There is no reason for any > individual to have a computer in his home." - that was in 1977, > according to wikiquote: > > https://en.wikiquote.org/wiki/Ken_Olsen One version of that story is he told it to David Ahl who was trying to pitch a <$2000 PDP-8 for the home market (IIRC a configuration like a 4-slot box with a KK8A, some basic I/O and a smallish MOS RAM card - too small to compete with a "real" PDP-8 system). Ken's reaction was an element of what led to David going off to found Creative Computing, as the story goes. -ethan
[cctalk] Re: Did Bill Gates Really Say That?
On Wed, Jun 14, 2023 at 12:21 PM Sellam Abraham via cctalk wrote: > Based on other videos of Dave's that I've watched he doesn't really know > what he's talking about so I wouldn't lend much credence to his apocrypha > either. Agreed. Some months back, Dave put out one of his videos with a click-bait headline that was, well, false. He did not respond well to that being pointed out. His "insider knowledge" hasn't impressed me. > > So I had always heard the quote "640KB is enough memory" being attributed > > to Bill Gates > > > > And apparently the man himself has denied it as well but it just will not > > go away... > > > > https://abcnews.go.com/Technology/PCWorld/story?id=5214635 It's entirely possible, even probable, BG didn't say exactly those words no matter what people think they remember. OTOH, I do remember, back in the day, that he _did_ make a similar statement, *but* unlike the myth, it wasn't to belittle PC users, but whatever he _did_ say was a caution to application programmers that the max available memory space _ought to_ be enough to write reasonable programs for the PC market, that there were ways to write programs that _would_ fit in 640K and you should be doing that. So I'm not gonna swear he said those words, I do remember something along those lines was said ~40 years ago. -ethan
[cctalk] Re: Getting floppy images to/from real floppy disks.
On Fri, Jun 2, 2023 at 4:38 PM Sellam Abraham via cctalk wrote: > On Fri, Jun 2, 2023 at 8:24 AM Ethan Dicks via cctalk > wrote: > > > I did see an actual 1970s station wagon loaded with RL02 cartridges > > once, pulled up at the dock of Baker Systems, the large Computer > > Science building at Ohio State (I suspect they were cleaning out a > > machine room and someone wanted the packs) > > It might've just been an enactment of the old adage for a video project. > Maybe they dumped the carts afterwards? :( This was in the late 80s when packs and such were still somewhat desirable. I did not see any cameras on the dock. -ethan
[cctalk] Re: Getting floppy images to/from real floppy disks.
On Thu, Jun 1, 2023 at 4:45 PM Alexander Schreiber via cctalk wrote: > On Wed, May 31, 2023 at 05:01:34PM -0700, Fred Cisin via cctalk wrote: > > What is the bandwidth of a station wagon full of 1TB Mcro-SD cards hurtling > > down the highway? > > $BIGNUM. I did see an actual 1970s station wagon loaded with RL02 cartridges once, pulled up at the dock of Baker Systems, the large Computer Science building at Ohio State (I suspect they were cleaning out a machine room and someone wanted the packs. Obviously I didn't know the right person that day). At Pole, we saved all the raw sensor data from AMANDA and later Ice Cube to DLT-format tapes (increasing the media/drive density over time) once a year, and it quickly grew to the point that we were stuffing several hundred TB of tape into an LC-130 to ship back to Wisconsin. It took 3-4 months to read last year's data once it arrived. So maybe not a 747 full of magtape, but still, a couple of cubic meters of DLT tape going 850 miles in 3.5 hours (Pole to McMurdo) is pretty decent bandwidth. The MCM->NZ leg was on a jet (C-17) so it upped the bandwidth, but on a larger plane so the effective capacity utilization dropped. -ethan
[cctalk] Re: ST-251 Data Recovery for Glenside Color Computer Club (GCCC)
On Tue, May 16, 2023 at 4:05 PM Dennis Boone via cctalk wrote: > > At the most recent CoCoFEST!, I brought home the old Glenside Club > > Computer Hard Drive. The mechanism is an ST-251... < > The best way to approach this, given the interchange issues with MFM > disk controllers, is probably to use one of Dave Gesswein's MFM Emulator > devices. It'll give you a flux image that can then be decode. I have an MDM Emulator and it's nice, on those occasions you are trying to read a supported drive (it supports a _lot_ of encodings, but not every single platform). Two layers - fortunately in this case, the low-level format is known (WD1002A-WX1) and that's good. I'd totally expect an MFM Emulator to be able to pull bytes off the drive. I am not a CoCo person so I have no idea what tools can be used to pull files from a raw pile of disk blocks there. -ethan
[cctalk] Re: The World Wide Web
FidoNet is still a thing too. So is USENET. Julf And bigger than ever (storage size wise.) - Ethan -- : Ethan O'Toole
[cctalk] Re: DEC RL device
On Sun, Apr 30, 2023 at 8:47 PM W2HX via cctalk wrote: > Can anyone tell me what I picked up at a NH hamfest this weekend for $20? I > see it says RL01/RL02. I have two RL02 drives and some platters. None of > which I have gotten around to trying. Other than a copious amount of pine > needles, what can this be used for? Or maybe the right question is, should I > not use it for fear of destroying an RL platter? > > https://w2hx.com/?prefix=x/VintageComp/Platter-Device/ Wow! Pretty neat - looks like a pack inspector for RK05, RL01/02, and RK06/07 based on the (blurry) instructions. Runout, at least, and certainly a few other measurements - would probably identify a pack that had been dropped hard enough to bend something (before you stuff it in a drive and ruin both). It doesn't look like a cleaner - I've seen an RK05 cleaner and it's a bit different - more about running a Texpad over the surface while slowly rotating than measuring anything. Cool find! -ethan
[cctalk] Re: One of Paul Allen's Museums
One oddity about LCM was that they seemed to be into non-disclosure agreements. It's rather bizarre for a museum to recruit people for a technical advisory group to help them with understanding old hardware, and then require them to sign an NDA for the privilege of helping them. paul I assume with the immense wealth PA had that anyone and everyone connected to him were sought out by people looking to try to pitch ideas, get grants, try to sell thing things, etc. Maybe NDA helped reduce that noise to the org. - Ethan
[cctalk] Re: One of Paul Allen's Museums
Question, were Paul Allen’s museums non-profits? Zane I am sure, tax writeoff. -- : Ethan O'Toole
[cctalk] Re: VCF East 2023 photos
It shouldn't be "part of the experience". It's poor planning and poor
management of the consignment area on the part of the organizers. This
same thing happened at VCF "West" last year and it was a catastrophe.
There was a line snaking down the hallway at least a fifty people deep and
they were waiting for 2-3 HOURS before it actually started moving. That
was 2-3 hours that attendees weren't in the exhibit/speaker hall engaging
with the exhibitors and their exhibits, and listening to the speakers. I'm
really disappointed to hear that, despite their prior experience, it seems
like they have not done anything to address this completely unacceptable
and entirely avoidable scenario.
Every bit of space that is currently available at InfoAge was used for the
event. Attendence jumped over prior years and the demand was
unpredictable. The weather in that area can be cold and rainy so outdoors
use is limited in planning. I figured there would be blowout attendence at
the 3pm streamer panel in Saturday, but crowd wasn't an issue. Meanwhile
at the dedicated swap meets at InfoAge attendence wasn't that crazy at the
last one. Maybe it's because it's tax return time?
If VCF could raise enough money to finish off their new space at InfoAge
and get a CO that would help a ton next year. But that is quite a bit of
money intertwined with government legal red tape.
Trust me there will be big discussions about how to try to fix it for the
future.
Also the event could use more volunteers for next year as well.
- Ethan
[cctalk] Re: 3.5' 1.44 & 720K compatible Read/Write FDDs
Is there a list of floppy disk drives which could read and write both 3.5"
1.44mb and 720k diskettes?
Replace any SMD electrolytic caps on the drive pcb if there are any.
- Ethan
--
: Ethan O'Toole
[cctalk] Re: Knockoffs, was: Low cost logic analyzer
I once heard a story from someone* who was told by a journalist that while said journalist was interviewing Richard Stallman he was [WARNING: GRAPHIC CONTENT COMMENCES HERE] picking the jam from between his toes and eating it. Oh, that's a thing of legend. Fear not, for there is video. https://www.youtube.com/watch?v=I25UeVXrEHQ - Ethan
[cctalk] Re: mainframe vs mini
On Thu, Mar 9, 2023 at 5:05 PM Cameron Kaiser via cctalk wrote: > This has been around the block: > > You can lose a screw in a micro. > You can lose a screwdriver in a mini. > You can get lost in a mainframe. We had an Amdahl in the middle of a multi-thousand-square-foot computer room (one of several) at work 25 years ago. I do not know/remember the model number but it was made of up several cabinets not in a line. It had such a convoluted layout that you could literally stand in the "middle" of it and not see outside. If you stood in exactly the right spot, the blank panels lined up and made the visual appearance of a box with no exits. You _could_ get lost in that one, as long as you didn't take half a step away. -ethan
[cctalk] Re: Knockoffs, was: Low cost logic analyzer
If you posted your design as Open Source, someone else producing it isn't a knockoff, it's the system working as intended. -- Chris I remember a talk by LadyADA of Adafruit at HOPE about starting a company making open source hardware and success and all that. It's easy if you have the marketing and big revenue stream, but eventually people will copy the designs. Also there are cases where multiple people have the same idea, I have projects that I started and didn't finish but I bet if I look around someone else has made the same thing and filled in the gaps. The first XT-IDE I ever came across was on I think a Chinese site called Seed Studio. From memory it was a single CPLD (I think?) and EPROM, it was a pretty sexy design but I've never seen them in the wild. I reached out to them and they said they would produce them. Later I found out about other ones and own some of the Glitchworks ones and have bought a few of the TexElec ones for special laptops (Tandy 1400FD / Yamaha C1.) Also, big HP versus USB logic analyzer. I had one of those old HP logic analyzers a while ago and it was really slow. Way easier to use the USB ones when it comes to portability and software speed. Plus easier to store captures, share data without a GPIB plotter, etc. I have one of the DSLogic ones and it does what I need, and as I recally there is a hack where you can solder in a SMD DRAM IC and expand the memory (upgrading it DIY to a higher model) if one cares to. Don't know if it's a clone, didn't research it that hard. Sold the HP years ago, never up-paid for the Rigol with the logic analyzer functions since the USB ones were so much cheaper in comparison. -- : Ethan O'Toole
[cctalk] Re: Visiting the computer history museum (chm)
The Silicon Valley of old is basically dead. The magic is gone. The two suplus stores are gone (Halted and Weird Stuff Warehouse.) Only thing I can think of that I would recommend is the Musee Mechanique over in San Fran. https://en.wikipedia.org/wiki/Mus%C3%A9e_M%C3%A9canique For suplus parts I guess you gotta go to Shenzhen these days. -- : Ethan O'Toole
[cctalk] Re: Why the Floppy Disk Just Won't Die
The mylar substrate would probably be the easiest. I don't know if anyone's still making audio tape, but the coating equipment might be the same. I don't know how to find the proper stuff for the goo, however. ATR Magnetics (www.atrtape.com) and others still produce audio tape. They have normal consumer-style stuff up to the 2" reels. Not sure if the 2" stuff they sell will work on digital machines like the Sony DASH machines. Cassette tapes are kind of back a little as well and apparently there are duplication houses for them again. -- : Ethan O'Toole
[cctalk] Re: on the origin of home computers
On Wed, Mar 8, 2023 at 3:59 PM Bill Gunshannon via cctalk wrote: > I had some good sized iron in my home in the early 80's. We (my family - I put up 1/3, my mother covered the other 2/3) got a PET in 1979. I came home from my first Dayton Hamvention in 1982 with a PDP-8. If a high school kid can scrounge a PDP-8 by the early 80s, I'm sure an adult with a real job could have done it a lot earlier. -ethan P.S. - 90% of what ran on that PET was games - commercial ones bought from Creative Computing and Instant Software and others, as well as lots of games typed in from books and magazines (Creative Computing, BYTE, Micro, etc). We didn't have a printer and the only storage was cassette tape, so word processing and other "serious" applications were off the table. I did have some utility firmware - an improved machine language monitor (NMON), which I used to write better games (hand port of Scott Adams' engine from BASIC to 6502 machine code), BASIC Toolkit, and BASIC Aid, used for writing better programs in BASIC. Yes, Bill, arcade games were better, but they cost $0.25 a play and I could play what games we had for hours on the PET. We didn't have an Atari or other home video game console. I also typed in and played several text adventures, something that was not available on a console or in an arcade. I'm not saying that nobody did "engineering work" on a home computer, but by 1980, we sure were playing a lot of games on home computers.
[cctalk] Re: Tadpole RISC laptop RAM modules
I don't think it's the connector, but it's junk if it isn't anyway, so I might see. These things screw in place and the fit was tight getting it out so it would boot again, so I don't think it wiggled. Still, would be nice to know a source for spares because it seems like others on this list have had similar problems with theirs. It might be possible to transplant DRAM ICs from other SIMMS onto the Tadpole memory modules to refurbish them. - Ethan -- : Ethan O'Toole
[cctalk] Re: Tadpole RISC laptop RAM modules
Well, this is the second Tadpole laptop RAM module I've had go bad on me (one
in my PA-RISC PrecisionBook and now one in my SPARC UltraBook IIi). These are
the maroon-red 256MB or 512MB screw-in modules marked "Huxley Only" using a
custom friction fit connector, not regular SO-DIMMs. I can't find an obvious
part number on them and searching for Tadpole RAM modules just finds the
rinkydink 8MB parts for the earlier SPARCbooks.
Can you tell if it's one of the DRAM ICs or if it's the connector? Deoxit
on the connector then reseat?
- Ethan
--
: Ethan O'Toole
[cctalk] Re: WTB: Acorn A3010 or A4000
Looking for an Acorn A3010 or A4000 + KB/Mouse, happy to repair it. Also Sinclair +3 with some disks Also BBC Micro Also Amstrad CPC 6128 color. Could forgo monitor and build my own PSU. - Ethan Still looking (though I might have line on the +3) -- : Ethan O'Toole
[cctalk] Re: Store with "vintage" computers and parts
I would be interested in knowing some of those options. Thanks, Will Brave Search / Brave Browser is one. Yandex is a Russian search engine that can come in useful sometimes. Trying to find ISO CD images of discs for music hardware (Samplers) it feels like the internet through google is way smaller than it used to be. The bad thing is there is a ton of knowledge on facebook that isn't indexed to the public web. -- : Ethan O'Toole
[cctalk] Re: WTB: Acorn A3010 or A4000
Hi, Ethan, Whereabouts are you? I'm in York, UK, and I have more than one spare BBC Micro. I don't have an A3010 but I do have an A3020 (red function keys) if that's of interest. Private email sent! The A3020 and BBC Micro are of interest! Thanks! - Ethan -- : Ethan O'Toole
[cctalk] Re: Store with "vintage" computers and parts
In this case, "bryanipad.com" appears to be available. But... my name is Ethan and my old tablet is Android :-( -- : Ethan O'Toole
[cctalk] WTB: Acorn A3010 or A4000
Looking for an Acorn A3010 or A4000 + KB/Mouse, happy to repair it. Also Sinclair +3 with some disks Also BBC Micro Also Amstrad CPC 6128 color. Could forgo monitor and build my own PSU. - Ethan
[cctalk] Re: Store with "vintage" computers and parts
The address is very suspicious, as it does not seem like a very good website name, and ends in .shop, which valid shops in our hobby rarely if ever use. Problem is all the .com addresses are squatted on now, so people are slowly starting to move to alternative things. - Ethan
[cctalk] Re: Computer Museum uses GreaseWeazle to help exonerate Maryland Man
What do you guys think of the "archive-ness" of current solid state
devices? M.2, NVMe, SSD, or even USB thumb sticks? A friend proposed
that when one of those starts to go bad, any kind of partial data recovery
becomes difficult - but any more difficult than the old traditional
magnetic media?
I thought Flash could only hold the data in them X amount of years until
the junctions discharge or whatever? It's less permanent than decent
quality optical or pro magnetic media?
You have to plug them in every so often to refresh I believe.
- Ethan
--
: Ethan O'Toole
[cctalk] Re: Excellent CHM Article on Apple Lisa Software (Apple Archive)
Companies don't care about history. It does not affect the next quarter's sales. I had serial number 1 of a Radio Shack shortwave receiver and offered it to them. A CEO I know of a company who's products I use has commented that he is always thinking forward, doesn't dwell in the past. Otherwise there would be layoffs. - Ethan
[cctalk] Re: Computer of Thesus
On Mon, Jan 23, 2023 at 6:09 PM Sellam Abraham via cctalk wrote: > I submit that the //gs isn't even really an Apple ][ properly. > It's more like a quasi-Macintosh with really good (not perfect) built-in > emulation of an Enhanced //e. That totally makes sense. I never got into the //gs and that kind of frames it: I'd rather just use a //e (which is still late for me) or a ][+ but that's because I first used them back in the Integer BASIC days (and watched friends do the DOS 3.2->3.3 conversion) then used them heavily in 1984. It's just where my experience falls. -ethan > Sellam
[cctalk] Re: in need of 2.5" disks
I saw it at Comdex, and then never again. Nintendo Famicom disk system uses some kind of odd sized not swure disk. -- : Ethan O'Toole
[cctalk] Re: 2 sets of IRIX, 2 Indys and I1
Question is are these versions of Irix suitable. Or couldnI do better. And on account of SGIs licensing scheme, which attaches a specific os version to a maxhine (or vice versa), does that entitle me to obtain and install those specific versions. Put anotjer way if I obtained images from somewhere, installed the correct versions of Irix, would thoae machines then be legit? Or am I supposed to pay through the nose for a subscription or whatever? Depends on what software you want to run and if it needs the last version of IRIX. I know there are people that have ported Yum (I think) to IRIX and have been producing modern compiles of software but not sure how beefy the machine needs to be. You can find tons of IRIX CDs right here: https://archive.org/search?query=irix=3 Notice that is page 2 and it's so full of IRIX software and CDs it's crazy. Hats off to the archive on this one. - Ethan
[cctalk] Re: [SPAM] Re: what is on topic?
On Sun, Jan 8, 2023 at 11:52 AM Liam Proven via cctalk wrote: > > Win95/Win98 would be happy with a PC/AT 286, with appropriate RAM > > Nope. 32-bit only. 386DX or later. I tried it and benchmarked it at > the time of release. And it beat WfWg 3.11 by a significant margin, to > everyone's amazement. I have a memory of installing Windows 95 on a monochrome 386SX laptop w/4MB of RAM in August, 1995 at McMurdo because that's the equipment we had on hand when Win95 arrived on the continent. It was unpleasantly slow but it did run. Way better on a 486 w/8MB. -ethan
[cctalk] Re: Diablo series 30 or Dec RK03
On Sun, Jan 8, 2023 at 1:50 PM Chris Zach via cctalk wrote: > That will be complex. I had an RK8 disk controller (the 6 foot cabinet > that was it) along with a pair of the RK03 disk drives and it was (a) > insane, (b) heavy beyond belief, and (c) finicky. I think I've only ever seen pictures. I know I haven't seen one up close. > It also required Data break which is not built into the stock pdp8/L. That's just a few common modules, fortunately. > You would need a BM08 box, and as I'm looking for one myself they will > be tough to get :-) Absolutely. Not a lot of benefit having storage without memory extension. > You might be better off getting your 8/L working and trying things like > FOCAL on paper tape and other simple paper tape/serial based stuff. > Running OS/8 will require either a pdp8/I (with the extra memory, data > break, and helpful things like the EAE) or as I mentioned a BM08. FOCAL is absolutely a good starting point for making a 4K PDP-8/L do _something_ interesting. I haven't ever tried doing assembly using the paper tape tools (it's several passes and uses quite a bit of tape) but I have assembled small programs by hand and toggled them directly into the front panel. Obviously that's no fun for anything over a few dozen instructions. -ethan
[cctalk] Re: Diablo series 30 or Dec RK03
On Sun, Jan 8, 2023 at 6:40 AM jos via cctalk wrote: > On 08.01.23 01:51, jake utley via cctalk wrote: > > Hello everyone I’m a young collector (18) of 60s and 70s minicomputers and > > micros. I have been restoring a PDP-8L and would love to find ether a > > Diablo series 30 or Dec RK03 removable cartridge drive to go with this > > system. > > Is it even possible to add a diskdrive to a PDP8/L ? My 1970 "Small computer > handbook" only mentions TU55/TC01 and DF32 as mass-storage options for the > 8/L. Both are essentially unobtainable. Indeed. I have had a PDP-8/L since I was in High School (eons ago). I have never come up with mass storage for mine and it's long been a goal to be able to do more than paper tape programs on it. Dry so far. Posibus storage devices were, IME, less common than Negibus devices (which would then require a DW08 and by the time you bought all of that, why didn't you get a PDP-8-i in the first place? (especially since you were memory-limited on the -8/L) > Maybe sell the 8/L and get yourself an 8/E or /F ? Much more flexible. I do get wanting to max out an 8/L. It was my first and I'd love to get it doing more things, and it's really cool that you can easily see what's happening at the gate level (possible but less convenient with an Omnibus machine), but there's only so much you can do with _any_ 4K PDP-8, and memory expansion boxes for the 8/L may be rarer than Posibus storage devices. It's a lot easier to bring an Omnibus machine up to 32K and there are lots of vintage storage options. Recreating these things with modern components is always a possibility, of course, but I've only ever seen a couple of one-off devices ever come out (like a Posibus DF32D emulator implemented in TTL that happens to need a now-hard-to-find 128Kx16 NVRAM) Personally I'd love to see some Posibus devices get recreated but after this long, I'm totally willing to see if I could get SerialDisk working with an add-on serial port on an -8/L or unexpanded -8/i. My own (perpetual) goal is to run OS/8 on a pre-Omnibus machine. Haven't pulled all the resources together for that yet. -ethan
[cctalk] Re: SGI vs. Mac
I thought the end of SGI hinged on two things: banking on the Itanium and giving up on MIPS, and their Graphics experts went off to found a company called Nvidia... the rest was inevitable. Founder of SGI wrote a book and in it he said he wanted to get into the PC Graphics card market and thought the writing was on the wall but the gravy train from the gov buyers was too good. Until it wasn't. I remember (in the workplace) when we started seeing PC clusters take the place of the big SGI boxes. For a while there was a claim that the graphics output on SGI was more accurate and the PC stuff fudged it (important in sims I guess) but we see where it all ended up. Really without the US government as a customer I wonder how many of these companies could have made it on industry alone. - Ethan
[cctalk] Re: SGI vs. Mac
Don"t know what an Elan is. I do seem to recall suddenly an Indy with no
graphics output, intended to be used as a headless server.
The SGI Challenge S is an Indy sized machine that is meant as a server.
They get rid of the graphics and replace it with a board that adds a 2nd
network interface and two additional differental SCSI interfaces.
- Ethan
[cctalk] Re: what is on topic?
On Tue, Dec 20, 2022 at 5:35 PM Bill Degnan via cctalk wrote: > We used to shun anything newer than and including the IBM PC but > time.marches on. You're safe if you discuss systems produced before 1990. > After that put an OT in the front of your subject so as not to offend the > purists. Personally I think anything built after 1995 is too new for > cctalk, but thats just me. As mentioned elsewhere, the old "10 year" rule is long irrelevant. I think 1995 is a good general cut-off for a strictly time-based threshold, but it's not a hard boundary - PPC Macs I would think should still be in bounds. A softer rule would probably be "(nearly) anything goes except nearly-current Windows PCs". If a machine can run WinXP, it's too new. Also as mentioned, there are plenty of lists about modern PCs. -ethan
[cctalk] A UK Vintage Computer exchange buddy?
Hello, I have looked at vintage UK computers on Facebook Marketplace and the like. The people usually will not post, especially to me in the USA. They are normally looking for local collection. Anyone in the UK want to be a vintage computer swap friend? Looking to get some systems from there and could help get systems from here in return. I am in the USA. Private message if interested! - Ethan -- : Ethan O'Toole
[cctalk] Re: Inline Serial Device?
On Sat, Nov 12, 2022 at 8:23 PM Sellam Abraham via cctalk wrote: > I recommend the DEADBEEF dish. FEED FACE DEAD BEEF -ethan
[cctalk] Re: Inline Serial Device?
On Sat, Nov 12, 2022 at 12:18 PM Chuck Guzis via cctalk wrote: > On 11/12/22 02:28, Tony Duell via cctalk wrote: > > ... This is the sort of > > thing I'd do with a couple of transistors or an NE555 depending on > > which turned up in the junk box first. > > One thing that a small MCU has over a 555 is that it can be programmed > once and you can be assured of its frequency stability. No fooling with > pots and caps to get the thing to work the way you'd like. Yes, that, plus since many products have a hardware team and a firmware/software team, the hardware can be designed to general requirements and sent out for manufacture while the software team has time to write the firmware (and make changes long after the hardware is set). One of the first times I encountered this was stripping some old emergency exit lights for parts c. 2008. The switching supply had an 8-pin PIC for the oscillator instead of a 555. Yes, a 555 could have done it, but the PIC didn't need any external components to set the frequency, components that can drift with age, and components that take up board space. Even if the 555 and MCU were identical in cost for the IC, the MCU was cheaper because of the smaller footprint. Additionally, the designers had some flexibility. To change the frequency with a 555 after manufacture is an expensive proposition. With an MCU, if it's flashable in-circuit (clip or possibly programming pads near/at the MCU), then one can change the behavior without melting any metal or purchasing components. While one may never need to change the frequency of a SMPSU oscillator after initial design, there are plenty of products where it's handy that the hardware guys can say "here's an output that can go from 1/10Hz to 20Khz - what do you want it to be?" and not worry about design limitations, just set the frequency in the firmware and it does that. You can build some generic hardware (X inputs, Y outputs with Z mA current drive) and fine tune things later, or have variations on what the inputs mean and not have to change the PCB. Yeah, the 555 is extremely simple and is well known and is fairly cheap, simple MCUs are simple (and cheap) even if they aren't 100% deterministic like a chip with 20-30 transistors. There's economic advantage in flexibility. -ethan
[cctalk] Re: 14 DZ11's for sale/whatever
On Tue, Nov 1, 2022 at 12:01 PM Paul Koning via cctalk wrote: > > On Oct 30, 2022, at 2:49 PM, Wayne S via cctalk > > wrote: > > > > The difference between dz and dh interfaces is that the dh used dma instead > > of interrupts to get characters to the cpu... > > No, it doesn't. I was confused about this but was recently corrected. > > The DH11 does DMA output, but not DMA input. I don't know any DEC serial > port devices that have DMA input; it would make very little sense to do that > since input generally is one character at a time. Yes. I was going to mention this in my previous reply but got sidetracked. The big benefit for DH11 and DMF32 and 3rd-party DH11 work-alikes (Emulex CS-21...) is that since under normal workflow, many times more chars go out than come in so DMA-out saves a lot of overhead when blasting screens of stuff (like refreshing your page in EDT...) and people don't type all that fast by comparison. Where we used to have problems is having multiple Kermit sessions on our serial ports. Those hammer both ways. Fortunately, I wasn't trying to support PDP-11s with split baud rates like 1200/150 that were used to _really_ reduce input interrupt frequency. Our machines kept up at 9600/9600. -ethan
[cctalk] Re: 14 DZ11's for sale/whatever
On Sun, Oct 30, 2022 at 2:49 PM Wayne S via cctalk wrote: > The difference between dz and dh interfaces is that the dh used dma instead > of interrupts to get characters to the cpu. It would be transparent to any > software. > I did a write up on them 40 years ago justifying the replacement of a dz with > dh saying that decreasing interrupts would increase performance on my VAX > 780. It did, but just a bit. To make a big difference, you’d have to have a > LOT of people banging away on serial terminals and rs-232 connected printers. When I ran Unibus VAXen in the 80s every day at work, our small machines had 5-9 serial ports for 1-4 users and our largest machine had 57 serial ports (multiple Emulex CS/21 and at least one DEC DMF32 plus the console) and several dozen users. We never moved to terminal servers or other external connection management. It was all individual serial connections routed to offices and workrooms. I think our peak usage was 50-60 active users but at that point, the 8MB of physical memory started to be a constraint. I don't think the 11/750 could have handled that many users on DZ-11s. -ethan
[cctalk] Re: Large private collections
I have seen system source both the museum part and the warehouse in the back. The rhode island.museum and warehouse is probably larger. Not that system source is not substantial. Bill Ohhh yea, you might of visited System Source before the expansion. Did you see the Cray 1? There is the Cray room now with the raised floor. Also Xerox Altos systems and all that. Tons of other systems with that haul (800+?) - Ethan -- : Ethan O'Toole
[cctalk] Re: Great Vintage Computer Heist of 2012
Don't be pedantic. You know what I mean. Anyway, in the US, there are *significant* barriers to cross for people taking your land. And for the younger crowd it's very expensive now. Not like the old days (assuming you live near a job center.) - Ethan
[cctalk] Re: Large private collections
I suspect Jim Austin has one of the largest collections that's publicly documented... https://www.computermuseum.org.uk/ .. but many are very private about what they own Dave Indeed! Looking down their list it's quite impressive but I think System Source has them beat. I don't see a list of systems on the system source website though so I have to go from memory and what I know. Not sure how big the collections are behind the scenes at Living Computer Museum, CHM or that place down in Georgia. And who knows how many other Computer Reset Warehouses are out there that we don't know about. -- : Ethan O'Toole
[cctalk] Re: Great Vintage Computer Heist of 2012
Own your land. Museum or individual. You never own your land. They can always take it. - Ethan
[cctalk] Re: Large private collections
However you define it, who has the largest private collections? Is there anyone who claims to have the largest private collection? I hypothesize that there is a terminal size where it becomes unmanageable. Bill Largest one I know of would by System Source in Maryland? And an awesome one at that. - Ethan
[cctalk] Re: Seattle Computer Products!
Yes. I have a description of my recreation of the Gazelle on my web site, as
well as notes on restoring the one for
VCFe.
Rich
Very interesting! Reading through it all now. I notice you use Tarbell
disk controller... difficult to use the SCP DiskMaster? I don't find many
references to systems running it. It supports SD/DD 5.25/8... I had
planned to go 5.25"
- Ethan
[cctalk] Re: PDP 8a front panel hardware
On Wed, Oct 12, 2022 at 11:36 AM Paul Koning wrote: > > The clip nut is 10-32... > > That's the same clip nut used on H-960 racks. I saw some at the local > hardware store recently. An unusually well stocked hardware store, > admittedly, but clearly they are still current items. It's the same threading but not the same style. The H960 clip nuts I have a real "nut" wrapped in a thin metal frame that wraps around the rail. This clip nut is a bit of plate steel with a machined and threaded "dimple" in the middle, and a small tang to latch into a thin metal carrier that looks spot welded to the bracket. You could probably use a rack clip nut in this application but I think the hole in the bracket would have to be a tad larger for a standard clip nut to engage, and then the cast metal front panel would be resting on the face of that clip nut clip instead of directly on the metal bracket with this design. It would probably affect a tight seat, and might lead to scoring on the inner face of the casting. Probably wouldn't matter much in practice, but a design and UX engineer might not like the difference. -ethan
[cctalk] Seattle Computer Products!
At this point I have achieved the SCP CPU card, a CPU support card and a Disk Master card. So hopefully all I need is some kind of 16 bit RAM board and a 4 slot S100 backplane and I can boot 86-DOS. I have started to read through the documentation on the hardware. Has anyone else been down this road and built a system to run this? - Ethan -- : Ethan O'Toole
[cctalk] Re: PDP 8a front panel hardware
On Tue, Oct 11, 2022 at 7:21 PM Vincent Slyngstad via cctalk wrote: > Bob Armstrong sent some pictures from Jack, which helped my find the > photos I knew were online somewhere: > https://forum.vcfed.org/index.php?threads/adding-a-programmers-console-to-a-pdp-8-a.75942/#post-921828 That's exactly what I have. -ethan
[cctalk] Re: PDP 8a front panel hardware
On Tue, Oct 11, 2022 at 1:17 PM Vincent Slyngstad via cctalk wrote: > On 10/11/2022 10:08 AM, Tony Duell wrote: > > On Tue, Oct 11, 2022 at 6:04 PM Vincent Slyngstad via cctalk > > wrote: > > > >> Those are the ones. The 3D printed parts are essentially triangular > >> blocks that mount to the rack and have a drilled and tapped hole for the > >> recessed Allen screw. As a 3D Printed part, looks good. > > Why on earth would you 3D print something like that? Machining it from > > a metal block would be a lot stronger. Strength isn't the only parameter here. A plastic block is plenty strong enough unless you routinely pull down on your front panel when you are standing up. I _am_ a fan of small machine shops, but even though I have access to a very nice one at our Makerspace, it doesn't take me that long to download a part file and press "print". > The DEC part is essentially bent bar stock, with a nut press-fit into > it. Also easy to to do if you have the tooling. Yep. I have mine right here. My micrometer is elsewhere, but looks like it's made from 1/8" steel flat stock (with anti-corrosion plating), and has 3 bends (apex and two ends), a clip-nut for the machine screw in the cast face, and two mounting holes. Not hard to make with a mill (or a file) and a break. The clip nut is 10-32, BTW. I just checked. No more difficult to source tooling than 6-32 If you made it from metal. you could skip the clip nut and tap the bracket itself, but if you removed the face often, I could see that eventually stripping-out. > I know a lot more folks with a 3D printer than I do the folks with metalwork > experience. Agreed. I know lots of people with 3D Printers that cost $300 USD or less, and they are much easier to learn to use than learning how to run a mill (safely). There's absolutely nothing about this part that you couldn't make on a 10-year-old tiny hobby 3D Printer. It's not detailed and can easily be made from ABS or PLA (the most common plastics). If you printed it on its side (with the notch facing "up"), with unbroken filament going around the perimeter, it would be a lot stronger than printing it "point up" in layers. Your mounting holes might be a little more ragged but they are covered up anyway. I haven't printed Vince's parts but on the surface, they look good. One possible improvement could be to design in a pocket for a 10-32 nut. There are ways to print parts and pause the printing to install metal hardware and overprint for retention. It's not a beginner's technique, and heat-staked inserts are easier to apply, but a captured nut can be made to float. -ethan
[cctalk] Re: 8" floppy diskette storage cases
I have contacted the seller, and kindly asked as a gentlemanly as I possibly
could.
I'll see what happens
Don Resor
If the seller will use PirateShip that can knock down the price of
shipping quite a bit, UPS and USPS only. Good news is it, unlike so many
others, can actually give you a PDF that is 4" x 6" for a thermal label
printer without hassle.
Charging fees on shipping is eBay's way of stopping people from listing
items for $1 with $49 shipping to get around paying ebay fees.
- Ethan
[cctalk] Re: z9 (s390x) mainframe up for grabs in Melbourne, FL
Will the damage from Hurricane Ian cause problems for anyone trying to retrieve it, and any idea if the Storage Unit suffered storm damage? Zane Melbourne Florida is near Cape Canaveral, it's on the East Coast and probably protected by the cape. Shouldn't be any water damage. Cool surplus place there MRAM Surplus or something. One of the employees had stuff like full rack Onyx and all that. - Ethan -- : Ethan O'Toole
[cctalk] Re: Data Systems Designs floppy interface cross-compatibility?
On Sun, Sep 18, 2022 at 2:30 AM jim stephens via cctalk wrote: > I'm getting ready to move to KC and my pile of DSD is back there. Hi, Jim, Cool. > I have both PDP8 varieties and PDP11. One complete system from Sellam > which hopefully contain data, etc. Dual booted for a friend he helped > maintain it. I have boxes of floppies that were the residue from a rescue in Champaign where Jack Rubin (who was closer) got first pick, and I got the things he didn't want/didn't fit in his car. From the directory slips and markings on the box, I suspect many of these floppies are double-sided and were used on DSD drives. Mix of PDP-8 and PDP-11 contents. > A guy in West Wendove NV had a number of subsystems and > I have all of them. We'll have to make a date to do a prisoner > exchange, and I'll loan / trade you what I've got, and hopefully come up with > working systems. Sounds like a plan. I'm not in a massive hurry, I just wanted to see if I had all the parts on hand to do _something_ > I've got two of the units with the SA-1000 drives as well. I've read the docs but haven't seen those in person. Kind of handy for a smallish PDP-11 setup. > Will take a bit of sorting, will have it on the list to get some stuff and > visit you later this year, but probably next year. Since it's already late September, I will just expect next year, but if something on your end changes, just say the word. I do have some "blackout dates" for various weekends through the end of the year - travel between here and NYC or here and Chicago, etc. > Glad you're looking into this. I don't think I've got enough > to run much on DEC disk hardware. I have an abundance of PDP-11 and PDP-8 gear. I'm trying to see what (still) works and fix what does not. So far, I have been entirely unable to even so much as read an 8" DEC floppy this year. I keep taking different stabs at it. Part of the problem is that I have mostly older (70s/80s) gear and the newer stuff (90s) doesn't work with old peripherals. Case in point, my DSD 8838 card has written in sharpie on the bag "does not work with PDP-11/73". That's not unusual. There are a lot of older Qbus cards that don't work with "MicroPDP systems" (usually meaning J-11). > I think among a pile of 8/As I got from sellam there are > DSD cards, but it was all unsorted. Hand over money load and drive > with a pile is the state of that lot. Right. > I have makings of 6 or 8 8/A's would like a couple, but DSD again > would be nice. I have three hex-wide Omnibus boxes, I'd like to keep 2 and sell 1 to someone, and I have two quad-wide Omnibus boxes -8/e and -8m) and I may want to get both of them running. I have an assortment of drives and peripheral cards, enough to load up all the machines, if they are all functional. Where the DSD drive comes into play is that it can format RX01 media (I have boxes of blank-blanks for CP/M machines) and mine (DSD480) can do double-sided media, which is only important to me for reading double-sided media. I wouldn't want to depend on a working double-sided drive for an operational setup. For real DEC drives, I have a number of RX01 and RX02 drive units and a box of spare parts (motors, belts, door latches, etc). Let me know when any of your plans crystalize. Most of my travel plans involve events like VCF so I can't haul lots of things because I already have a load of event-related materials. I also don't usually get out past Chicago going West. I haven't driven to St. Louis in well over 20 years. -ethan
[cctalk] Data Systems Designs floppy interface cross-compatibility?
Greetings, all, While getting ready for VCF Midwest etc, I have been spending a lot of hobby time in the past year digging out various DEC minicomputer items and testing/repairing them. To that end, I've been staring at a DSD480 on top of a PDP-8 rack. It's one of the ones with the DSD 26-pin interface. My question is that since there are several different devices with that connector, are any of them compatible with each other? Specifically, here are the DSD interfaces with a 26-pin connector: 802130 DSD210 PDP-11 Interface (26 pin) (2130) 802131 DSD440 DSD210 PDP-8 Interface (26 pin) (2131) 802132 DSD210 LSI-11 Interface (26 pin) (2132) 804430 DSD440 PDP-11 PDP-11 Interface (26 pin) (4430) 804432 DSD440 LSI-11 LSI-11 Interface (26 pin) (4432) 808830 DSD880 (SA850/SA1004) PDP11 Interface Card (26 pin) (8830) 808832 DSD880 (SA850/SA1004) LSI-11 Interface Card (26 pin) (8832) 808836 DSD880/20/30 (SA850/Q240) LSI-11 Interface Card (26 pin) (8836) It looks like the 2131 board is Omnibus and works with either the DSD440 or DSD210, but on the PDP-11, can the 883x interfaces work with older drives or do they only work with the DSD880 floppy/hard drive box? I remember where/when I got this DSD480, so it seems likely to me that I have a PDP-11/34 with an 4430 board in it. I could probably use an 2131 board just so I have an Omnibus interface. I also have an 808836 board but do _not_ have a DSD880. I've found the prints on bitsavers that cover the DSD440/480 interface so I know what signals are there, but I haven't found the equivalent docs for the DSS880, just user guides. Anyone here know enough about DSD products to shed some light? Thanks, -ethan
[cctalk] Re: Test Message
I see it (and I observed the same thing - just rejoined after having subscription problems stretching back to May, and didn't see any traffic). -ethan On Fri, Sep 16, 2022 at 12:09 PM Kevin McQuiggin via cctalk wrote: > > Pardon the test message, I have just re-subscribed to the list but have seen > no traffic on it for a couple of days. > > Kevin McQuiggin
[cctalk] Re: BBS memorabilia
Has anyone ever seen promotional videos showing Prodigy, Compuserv, Delphi, GENie, AOL? I've collected disks, but the systems are long gone so archived video is all we have to remember them by. When I was young, I remember seeing disks and pamphlets for these services in the box when upgrading modems. They had serious brand recognition. By the time the Internet was becoming available to the public, I remember being more interested in getting a Compuserv account lol. After getting our first Internet account in 1994, I was confused because I didn’t know where the “file areas”, “message areas” and “chat” were after being so used to BBS menus. Eventually I learned about FTP, USENET, and IRC. We even had a “yellow pages” paper book where you could look up topic specific FTP, USENET, and Gopher sites. Just a heads up in case you aren't familiar, there is a project out there where someone was pulling data from Prodigy cache directories (from installed software that was used, on old computers.) They were working to re-create Prodigy. Would be cool if someone re-created the others as well. - Ethan O'Toole
Re: Vintage Computing Hosting [Was: List migration]
Who else provides free vintage computer-themed web site hosting as a group service? I know neurotica.com (LSSM) does too, and I realize a lot of people have home servers that host their web sites on the subject, still, right? My shell host of friends is at a tier 1 colocation facility. 1.5ms to google, half a ms to aws and azure. Just spun up VMs for running a BBS for MAGFest and trying to figure out analog modem inbound for it. If someone needed to host a project for the community I could help, same goes with mirrors. My costs are fixed and the box is prety beefy (thanks to friends.) Shell host is probably 30 years at this point. -- : Ethan O'Toole
Re: Advice on Desoldering an IC
I am trying to remove an IC from my PDP 11/24 CPU, a DS8641. I am really struggling to desolder it. I am using the technique of applying fresh solder and then removing it. But after multiple cycles of this I think I am starting to damage the PCB. Are there any tips for removing ICs? Thanks Rob I use a Hakko 808 and have found cases where the pin size of the IC is close to the hole size, and then you can't get the solder out. Some tricks I have used include Chip quick. This is a different allow you "solder in" with existing solder. It has a lower melting point so stays liquid longer. It's great for SMD and troublesome through hole, but you have to clean it off and that part sucks. If you can get some of the legs loose on the chip and then apply some pressure to pull up chip and heat the troublesome pins, but be careful not to lift traces. This sometimes allows chip to "walk" up Flux also helps sometimes Hot air is another trick but probably left to modern boards. -- : Ethan O'Toole
Re: Possibly going up to VCF, stuff I would like to sell/get to proper people pdp8/12/HP stuff
On Mon, Apr 11, 2022 at 8:43 AM Chris Zach wrote: > On 4/10/2022 6:05 PM, Ethan Dicks wrote: > >> Ton of pdp8/12 IO cables. These are the black circular wire ones, I > >> think negibus. > > > > There's definitely some discussion going on about those. They are > > desired by 12-bit folks. > > *nod* To me classic computer stuff falls into two categories. There is > stuff that is common so you sell it for a reasonable price or trade it > or whatnot on Ebay/whatever. Q bus boards, systems, normal pdp11's, > stuff like that. You just either sell it on Ebay (whatever) or give it > to someone for a minimal cost of shipping and handling who has a system > and really needs it (think 11/24 CPU boards) Sure. > Then there is the stuff that is "priceless" and goes for stupid amounts... Agreed. > The IO cables fall into the latter category. So what's the best way to > have them find a home with a person who will use them and not just > another trophy in a box of parts or an exhibit in some museum? Thunderdome? ;-) But seriously, probably to ask here and on the Classic Computer Discord channel (a mix of folks from here and not from here, mostly US-based) who could even use such a thing. I have a couple of Negibus machines. The only one I'm really missing cables for is a PDP-8/S, so I can connect up a PT08 once I find/fabricate one. If someone had a PDP-12 or LINC-8, that would be, to me, a higher priority need (especially since I haven't even relamped my -8/S yet). I wish I'd gotten the ASR-33 that originally came with it (since some had the PT08 in the base) but alas, that was gone before I got there. Events like VCF concentrate the interested population - I've been part of a "12-bit panel", up on stage with Kyle Owen, Jack Rubin, Vince Slyngstad, etc., exactly the sort of people who would _use_ I/O cables not flip them. Trade stuff is harder. I know you are seeking external memory boxes for the -8/L, but those are quite rare. I just have the one and it's not an extra. Any 12-bit spare parts I might have are Omnibus bits. Cheers, -ethan
Re: Retro networking / WAN communities
Does anyone know of any communities / mailing lists / newsgroups / et al. for retro networking / WAN technologies? - PSTN / PBX / PABX There is a Central Office Groups.io list (which migrated from Yahoo Groups) located at https://groups.io/g/centraloffice . It is low traffic. There is a Discord server related to PBX and Telephone stuff, but will have to dig up that info later. It's pretty low traffic as well. - Ethan -- : Ethan O'Toole
Re: Possibly going up to VCF, stuff I would like to sell/get to proper people pdp8/12/HP stuff
On Sat, Apr 9, 2022 at 3:43 PM Chris Zach via cctalk wrote: > I'm thinking about going up to VCF in Wall next weekend. 22-24 Apr, as mentioned... I should be there too. > I haven't been > to it since it was the Trenton Computer Fest (think late 1990's) Totally unrelated event. > so I'm > not sure what the protocol is on tailgating, trading stuff or whatnot. > Appears that they have a "sale room" you drop things off in with prices. > Ok Yes. There's a "consignment room" and you leave your stuff with labels and prices and there are volunteers staffing it to collect money and record sales, etc. There's a house cut (but I am unsure how much it is so I don't want to just guess). > Stuff I could bring to get out of my house and into the right hands: > > Big box of pdp12 schematics. This came from my olden days when I had to > turn up a pdp12 because it will not fit in a station wagon. Still it > looks like board locations and a lot of 12 stuff. Big box, heavy to > ship, easier to drive over. > > Ton of pdp8/12 IO cables. These are the black circular wire ones, I > think negibus. There's definitely some discussion going on about those. They are desired by 12-bit folks. -ethan
Re: Possibly going up to VCF, stuff I would like to sell/get to proper people pdp8/12/HP stuff
I'm thinking about going up to VCF in Wall next weekend. I haven't been to it since it was the Trenton Computer Fest (think late 1990's) so I'm not sure what the protocol is on tailgating, trading stuff or whatnot. Appears that they have a "sale room" you drop things off in with prices. Ok It's April 22nd to April 24th :-) https://vcfed.org/events/vintage-computer-festival-east/ -- : Ethan O'Toole
Re: Data recovery (was: Re: SETI@home (ca. 2000) servers heading to salvage)
For those in the know, how much success - assuming a "money is no object" approach - do data recovery companies have in retrieving data from drives that have a) been overwritten with zeros using dd or similar, and b) been overwritten with random data via a more comprehensive tool? cheers, Jules I am pretty sure someone had a bounty out there, they give you a hard drive that had a phase on it that is stored linear on the platter. They write over it once with zeros. If you can recover the phrase then you win the bounty. It's unclaimed. Everyone talks about some theoretical ideas but no proof of it being done. My understanding is once you erase the data it's difficult to tell the difference between something recently erased and the noise floor. This was last time I looked into this which was a while ago. Maybe nation state has some ability but you or your customers data isn't worth the hassle. Prior employer would just have hundreds/thousands of pounds of hard drives ground up though. To eliminate any risk of data leakage. I am sure the same is done with SSDs by other companies and the US Government. Probably grinding up $9000 8TB SSDs all day. -- : Ethan O'Toole
Re: LSSM is chasing this, was Re: General Data? Computer Equipment Auction - GSA
In LSSM's case, it's a wholly-occupied 14,000 square foot commercial storefront building that nobody lives in, in a downtown shopping district, as distinguished from the typical private collection in a garage, basement, etc. -Dave Right, I know you have a real building and are open to the public and operate what I would consider a real museum. But where does one define a museum when it comes to randos, the small shops, the people just collecting donations for the price break, etc. Someone I know has a museum, collects stuff, no business entity for it, and it doesn't usually see the light of day. He says he plans to open a museum someday, but he has no real business plan AFAIK. He does have some stuff on display at another museum though. - Ethan -- : Ethan O'Toole
Re: LSSM is chasing this, was Re: General Data? Computer Equipment Auction - GSA
I interpreted "disappear into the black hole of a private collection" as
meaning "regrettably unavailable for viewing and/or use by anyone but the
collector". This has nothing to do with how well the systems are preserved.
And while the particular choice of words may be somewhat inflammatory
(although not to me), I agree wholeheartedly with the sentiment.
Private collector of computers, older video game stuff, pinball machines,
synth/music toys and now dabbling into 35mm stuff. A few friends in this
space.
Our stuff is ALWAYS going out and getting played with. From the
Smithsonian (SAAM events) to MAGFest events to Vintage Computer Festival
events (Remember, most of those systems on display for play are from
private collectors there to share!), to events that happened in Norfolk VA
and Chesapeake VA. Some of my stuff will probably be at the upcoming event
in Philly (Too many games.)
I mean what is a museum really? What about low attendence museums versus
private collections that serve tons of people? Aren't museums private
collections too?
- Ethan
--
: Ethan O'Toole
Re: DEC H500 Digital Computer Lab
On Fri, Mar 11, 2022 at 8:03 AM Tom Hunter via cctalk wrote: > As there is no real cctalk traffic other than test messages I thought I > post something a bit more interesting. Here is a short video of my fully > restored DEC H500 Computer Lab with an 8-bit counter implementation > including reset: Hi, Tom, Great post and timely. I recently got leads for my H-500 but I didn't get exactly "one set". I know I didn't get any of the longest wires but I also got a couple extra, I think, brown ones for the tips. I read through the handbooks and the closest thing I found was page 173 in the Workbook that mentions "Bundle of Taper-Pin Patchcords (107 of Assorted Lengths), Model Number 916, $30). Could you post how many of each color you have? It's possible, of course, that you don't have exactly "one set" either, but if you happen to have 107 wires, that's a good indication, especially if your tally matches mine anywhere. Here's what I have: 22 BRN ~ 3" ( 2-7/8") 30 RED ~ 5" ( 4-7/8") 25 ORN ~ 7" ( 6-7/8") 20 YEL ~ 9" ( 8-7/8") 10 GRN ~17" (16-7/8") 0 BLU - 107 -ethan
Re: 11/83 operating system load update -2
On Tue, Feb 22, 2022 at 9:29 PM Rod Smallwood via cctalk wrote: > 2. The PC I want to use is a DEC Celeibris FX ie the PC and its W95 > software is as supplied by DEC. . . . > 5. putR was supposed to be able to do this. It does not. Rod, My memory is that programs like putr need to run on "real" DOS, not a DOS window. So if you are trying to run putr without booting to MS-DOS 6.2 or older, that could be the source of your problems with it. > 6. All that is lacking is the right utility. I think other utilities (Teledisk, ImageDisk, etc) _also_ require MS-DOS not a DOS window under Windows. -ethan
