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OT: Vacuum tubes/Valves/VEDs today

by cclist＠sydex.com

A good article in ED today: https://www.electronicdesign.com/communiqu/article/21133402/tubes-luckily-t… --Chuck

6 years, 1 month

VHDL / IBM SMS Data gathering and HDL Synthesis Update

by cube1＠charter.net

Don't know if anybody much cares, but: The HDL synthesis aspect of the SMS data gathering / HDL synthesis application is coming along. I can now handle: - Oscillators (using a counter divider) - Delay lines (using a shift register, so limited to a reasonable number of FPGA clock clock cycles, so, say 200 ns is not unreasonable (20 bit shift register at 100 MHz). - Recognition and consolidation of individual signals into a "bus" when generating groups corresponding to a group of individual ALD sheets. (The individual ALD sheets use the individual signal names as they appear on the sheet). A simple database table associates a given individual signal with a bus, and identifies the bit in the bus that corresponds to the individual signal. So, I have not generated the IBM 1410 main oscillator, its main logic clock and its I Ring - used to control instruction decode. I have synthesized the logic clock into an FPGA and run it (with a slowed down 1410 oscillator so I could see what was going on.) Also, a word about VHDL - and the Xilinx Vivado. While GHDL is useful, I have found that Vivado is not slow at editing and *simulation*. Silly me - I got in the habit of synthesizing stuff before I tested it under simulation - partly because I didn't know any better at first. Vivado's waveform viewer has some advantages (and disadvantages) compared to what is available for GHDL. I have also started exploring a piece of "intellectual property" I can use - MicroBlaze - to allow my generated system to talk to my PC, via TCP, for things like lights and switches. (Kind of like how the Amdahl machines used to use first DG Novas, and later little UNIX systems for their consoles, giving them access to the internals of the machine.) I knew MicroBlaze existed, but now I have actually played with it a bit -- still learning. https://en.wikipedia.org/wiki/MicroBlaze

6 years, 1 month

Malfunctioning VT240 - help please

by charlesmorris800＠centurytel.net

OK. the keyboard is working properly as far as I can tell, data is going in and out, and I even swapped it for the keyboard on my VT220 and the same symptoms persisted. I just verified all four ROMs on the T11, and the ROM for the 8085, against the images I found on the MAME site. So far so good. One interesting finding - two of the lines (DAL3 and DAL1) on the T11 do change states several times, but once the self-test has crashed, they stay high with almost one volt of "wiggle". All the other data/address lines are either high, low or switching between a good 1 and 0. There are several places that the bus connects, including the ROMs, 1-bit dynamic RAMs and various octal latches & bidirectional buffers. I connected a 10 ma VOM between each line and ground (to make sure a low-resistance path (such as in the 'LS245 at E55) wasn't forcing it high somehow. All of the DAL15-0 lines requires more than 1.9 ma to bring it to ground (well, 50 mv burden at 250 mv full scale, anyway). That leaves the unlikely possibility that one of the octal TTL devices, or ROMs. has developed a weird internal pathway that only interferes with DAL3 & 1 on some bit patterns, but not all the time. Seems like a zebra rather than a horse. The only part that drives multiple low-order DAL lines at once besides the E19-22 ROMs is the E55 LS245. The T11 spec sheet says that a good logic 0 (<0.4 volt) should be possible with up to 3.2 ma sink... So I suspect the T11 has a couple of bad output pull-down transistors on those lines. Anyone got a spare T11 chip I can buy or borrow? Or send you mine to plug into your board and see if it fails the same way? :) thanks.

6 years, 1 month

: Unknown Intel blinkenlight panel circa 1973

by couryhouse＠aol.com

Add on? solid state memory unit? some semi companies made tjem. For add to Dec and dg?? Dunno. A guess ....?? ed smecc On Sunday, June 14, 2020 Joshua Rice via cctalk <Rice43 at btinternet.com; cctalk at classiccmp.org> wrote: Hi all. I recently bought a mystery blinkenlight panel. Closer inspection reveals it was manufactured by Intel in the early 70?s (1973), and some people on the book of faces suggested it was part of a ?device multiplexer?(?) I?m 95% confident it?s not strictly a ?computer? blinkenlight panel, but rather an attached device, but that still hasn?t helped me narrow down what exactly it was from. I?ve not seen any early Intel stuff as rack-mount, so i?m wondering if it was a prototype, or maybe a piece of internal/non-commercial hardware for Intel's own use. I?m hoping someone here might be able to shed some light on this mystery. Pictures: https://imgur.com/gallery/lD74oSy <https://imgur.com/gallery/lD74oSy> Thanks in advance. Josh Rice

6 years, 1 month

Thinking of selling my PDP's

by charlesmorris800＠centurytel.net

I am getting closer to retirement (although not close enough) and I'm considering selling off my PDP stuff, especially if I downsize and move. Everything's working, but I just no longer DO anything with either system... the adventure was acquiring all the pieces, fixing them and learning the software :) Anyhow I have an 8/A with cloned Programmer's Panel (Vince Slyngstad and I made it around 2006) and limited function panel, 32K RAM board (also have core), Philipp Hachtmann's USB interface board, RX01 floppy, two RL02's, and a high-speed (optical) reel-to-reel paper tape reader. OS/8 is up and running. Several spare RL02 packs. It's all in a tall DEC rack with an H-(something) power control box. The ASR-33 is not included, I'm keeping that. Also an 11/23+ (11/03 chassis) in a corporate cabinet with two RL02's, a 16-line serial interface, VT-220 terminal. Also an RQDX3 which is connected to a loose 3.5" TEAC floppy drive. Have RT-11XM, RT-11SJ and TSX-Plus 6.50 (all 16 timesharing ports are working too). So, I am wondering if there's any market for them (preferably as complete systems). Shipping would be difficult due to the size/weight (I'm in rural south central Missouri). I'm not looking to give them away, or to part out, but would entertain reasonable package deals rather than deal with the "LQQK! RARE!!" bull on ebay. I can send pics to interested parties. Let me know, thanks! Charles

6 years, 1 month

Is Power7 a bit too recent?

by dlr＠bungi.com

I have a bunch of Power7 720's I would like to get running, and I'm have a tough time tracking down any VIOS newer than 2.1. Does someone here have some 2.2.6 or later CD's they would like to sell me? Thanks! --

6 years, 1 month

PDP-8/A transformer hum

by derschjo＠gmail.com

Hi all -- I'm working on a PDP-8/A I picked up at VCF West last summer. After a lot of cleaning and some power supply repair it's showing signs of life (CPU seems to be at least minimally functional, core memory is going to need some debugging.) The transformer in the power supply is humming quite loudly, however, and I'm curious if this is normal for the 8/A (or is typical for an 8/A of this vintage). I'm used to the supplies in various other DEC machines not being exactly silent but this is a rather severe 60Hz buzz that you can clearly hear over the fans when the machine is in operation. Thanks, Josh

6 years, 1 month

Looking for Cobalt Qube cases

by laurens＠daemon.be

Hello, I'm looking for Cobalt Qube cases, preferably in North America. I would prefer non working Qubes as I don't want to deprive anyone of working ones. Doesn't matter whether it's a 1, 2 or 3. I'm looking to repurpose the cases. Thanks!

6 years, 1 month

DS10 Alpha question = Sata Drive card?

by bobsmithofd＠gmail.com

Can anyone recommend a SATA card that will work with a DS10 Alpha, and which OS supports that card? thanks bob

6 years, 1 month

TU58 dump tool on Linux? (Mattis Lind)

by john＠ziaspace.com

> Is there anyone that has already built a tool to dump TU58-tapes on a Linux > machine? I have the drive of course. > > There is PUTR. But it is DOS only and is written in assembler so it cannot > be ported easily. The other option is running RT11 on a PDP-11, but then > there is the hassle of getting the dumps off the RT11 file system. > > > It is probably not too difficult to use relevant parts of the various TU58 > Unix implementations out there to do something quickly, but if someone has > already done it, it would be great to not reinvent the wheel. > > I have approximately 80 11/730 and 11/750 console and diag tapes that > need reading. Just a thought - if the TU58 connects via serial, then what about running SIMH and giving it a serial device which is connected to the TU58? That could fix both problems - how to talk to the device, and how to deal with the data on the tapes. John

6 years, 1 month

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