July 2023 - cctalk - classiccmp.org

VCF and System Source Computer Museum swap meet this weekend

by Mark G Thomas

Hi, I am curious if anyone here might be planning on attending. https://museum.syssrc.com/artifact/events/3000/ The Vintage Computer Federation and the System Source Computer Museum are hosting a vintage computer repair workshop on Saturday July 22nd and Sunday July 23rd 2023 ... Mark -- Mark G. Thomas <Mark(a)Misty.com>, KC3DRE

11 months, 2 weeks

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OLD ftp.compaq.com Mirror?

by Ali

Hello All, I am wondering if anyone has a private or knows of a mirror for ftp.compaq.com that is older than 2014? All the ones I have found online, including the file at archive.org, are from 2014. By then a number of files and directories had been purged e.g. "/pub/supportinformation/techpubs" and "softlib1". I am looking for some old documentation and firmware for Compaq switches and Tape Libraries but if anyone has a full set of files I am happy to add them to a mirror. TIA! -Ali

11 months, 3 weeks

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Restoring Ultrix-32m 1.2 Floppies

by Henry Bent

Hi all, 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_… ). I am having difficulty parsing these images into a usable raw format for SIMH. As a reference, TUHS has a set of 1.0 floppies ( https://www.tuhs.org/Archive/Distributions/DEC/Ultrix-32M/ ) that are usable for installation purposes. (You can ignore the 1.2 floppies in that archive, they aren't actually a full set). The first disk of that installer, 32m-1.0-bin/01, has a bootloader that starts at byte zero as we would expect. This should be approximately equivalent to disk 1 in the Bitsavers set. 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. 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. -Henry

11 months, 3 weeks

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How to archive floppies

by Warner Losh

OK. I have about 500 DEC Ranibow floppy images that I've ripped over the years. I also have a number of .td0 images as well as other oddballs. Other than Lotus 123 needing to have funky sectors on one of its bigger tracks for copy protection, I think having the raw images suffice. I have some disks that I have multiple copies of (MS-DOS, CP/M, Winchester Utilities, DEC Rainbow diagnostics etc).I have a few copies of some software packages. I have a few disks that are clearly personal. And some of the variations of MS-DOS have different patches applied by various install programs (or debug scripts published in different trade rags of the time). And at least one has a special driver installed that overwrites the DEC Winchester for things like Univation). So, what I'd like to do is to is somehow organize all this. I wrote some software to extract files from the filesystem.So I'd like to have a separate copy of the expanded files. Lots of moving parts for 40-year-old floppies. I'm struggling with how to organize all this, how to keep track of this, and how to allow others to contribute their disk images and allow things to be studied and run. I'd like to keep the raw images (to mine them for drivers like the univation one I discovered). I'd like to keep the busted apart files to access them more easily, etc. Is there some book, website, paper, etc that I can use to to help me organize all this so I can share it with others? Is this even the right place to ask? There's got to be several people that have solved this issue before.... Warner

11 months, 3 weeks

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10 types of people

by Paul Koning

Seen on the GCC bugzilla: "actually, there are 10 types of people: those who understand ternary, those who dont, and those who thought this was going to be a binary joke" :-) paul

11 months, 3 weeks

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Don Lancaster has passed away at 83

by Sellam Abraham

Don Lancaster passed away on June 7. https://gilaherald.com/obituary-for-don-lancaster/ I hope his website is well preserved: https://tinaja.com/ Sellam

11 months, 3 weeks

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Shot In the Dark: Compaq System Manager Facility

by Ali

Really long shot, and I have asked here before without much luck, but anyone have a copy of the Compaq System Manager Facility 1.10 or 1.11 (or any version for that matter). This would have been released in 1994/95 time frame and is necessary for the use of the Compaq Server Manager/R EISA board. This is a very early EISA RILO board for the System Pro and Proliant line of servers. Please note this is not the same as the System Management Agents nor the Insight Manager. TIA! -Ali

11 months, 3 weeks

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WTB XVR-4000

by silcreval

Hi everyone, I recently dug out my V880 and all seems to be working brilliantly. I've always liked these machines and it would be nice to upgrade this to the V880z spec, ie by adding the mighty XVR-4000 graphics module. I know the XVR-4000 is a bit of a mixed bag, but would be fun to play around with this and also who can not be impressed with the shear size of the module. Must be one of the biggest Sun graphics 'cards'? Does anyone have one of these boards they would be willing to part with. Happy to pay a reasonable amount as I know these are not easy to find. PM me if you have anything. Ian.

11 months, 3 weeks

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IBM 1410 FPGA Status

by Jay Jaeger

Over the past couple of months I have been working on my FPGA implementation of the IBM 1410 1960's era pre System/360 system again. I am pleased to share that the CPU now passes a significant diagnostic, CU01, which tests almost all of the instructions, and also tests I/O with overlap and the priority feature (interrupts). Also, it runs at generally the same speed as the original machine (comparing the IBM estimates for 1000 passes), using the same logic as the original machine (though no doubt optimized by the process of taking in VHDL logic statements and turning combinatorial logic into lookup tables (LUTs), and some additions of "D" flip flops to avoid race conditions in latches and logic loops.) (The speed is the same because its "oscillator" - crystal controlled in the original - is now a clock divider/counter off of the FPGA chip clock.) For more details, see https://www.computercollection.net/index.php/ibm-1410-fpga-implementation/ Mostly the ALD (Automated Logic Diagram) data capture seems to have been very accurate. I really only had to do four things this year to get it to this point: - Make the necessary logic gate deletions / changes for configuration option S40/$40 - 40K of core - Add the ability to transfer a core image from the PC support program to the FPGA. - Fix some issues in the Assembly Channel because while almost all of the ALDs are for a 1410 with the Accelerator feature, several pages of the very important Assembly channel were for the base 1410 model. - Deal with a race condition during overlapped I/O These are generally discussed in individual blog posts off the above link. I really was quite happily surprised that when capturing the data on over two hundred ALDs with over 10,000 logic gates, over 4,200 individual unique signals, more than 12,000 signal names on individual ALDs, and more than 32,000 interconnections that there were not a lot more problems than these. (I may run into some as yet undiscovered errors involving the channels as I add I/O devices, though). I suppose that there were not more problems because for most of the individual sheets and in many cases groups of sheets I wrote VHDL test benches using the Intermediate Logic Diagrams (ILDs) as a guide, and of course took considerable care during the data entry process from the ALDs, checking connection counts on each logic block, for example. The last post ("Off to the Races") on the aforementioned web page also discusses the next expected steps: some more work on the PC/Console support program, more diagnostic tests, other support program enhancements, and figuring out how to go about I/O, especially since I don't have ALDs for the 1414 I/O Synchronizers. But I no longer have any doubts about the viability of this process, so long as the FPGA logic clock is somewhere around 10x the logic clock of the simulated machine. (I expect to try and "push it" by speeding up the 1410 logic clock to see at what ratio of the FPGA clock to the CPU clock things break down, as well). JRJ

11 months, 4 weeks

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Talking PDP11

by Douglas Taylor

I have a PDP-11/53 and have just started playing with an AAV11-C D/A board. It is a 4 channel D/A convertor with 12 bit resolution. Can it be used to play an audio bit stream? Here is simple code used to see if the thing was actually working: .title AAV11 D/A test ; .asect dbr0 = 170440 .=1000 start: mov #7777,r0 4096 value to R0 mov #dbr0,r1 first D/A buffer out loop: mov r0,(r1) transfer value in r0 to D/A out dec r0 subtract 1 from D/A value bne loop br start loop back to start I was surprised to see that it took ~34 ms to run through all the numbers from 0-7777, that is about 34 Hz. The manual says the 'settling time' is 6 microseconds. Is this fast enough for audio? How would you convert a modern audio file into 12 bit integers? Doug

11 months, 4 weeks

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