unix

More SGI computers

I got some new SGI computers. I was surprised because I thought the SGI guys from the Czech Republic gave me all their leftovers. I had to go to one of the original SGI offices in Brno this time. The office design was very 90s and there were classic SGI artworks on the walls. All the people there are now HPE employees but many of them started there working for SGI when every employee had an Indy or O2 on their desk.

The “loot” contains:

  • Two SGI O2 / MIPS R5000 / 2x SCSI HDD / the one with the older logo has an analog AV module installed
  • SGI Visual Workstation 320 / 1x Pentium II / a basic configuration with an IDE HDD
  • SGI Challenge / MIPS R5000 / basically an Indy without audio ports and a graphics card
  • Two sets of keyboards and mice, the PS/2 one is for O2 and the USB one for SGI 320

New Item: HP Integral Personal Computer

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I am trying to avoid buying any old computer, but a friend of mine and I made an exception in this case and bought this together. Somebody in Prague offered a non-working HP Integral Personal Computer (1985) for $420. It was just 15 minutes of traveling from my friend’s home, so he visited the seller and told him that he would buy it if he could look into it, measure voltages and check for corrosion (either from caps or a leaked battery). The seller agreed. They briefly started the computer, but only horizontal bars were flashing on the screen. Then he disassembled the system, and everything was in pristine condition and all voltages were ok. After reassembling, he just paid and took it home.

When I visited the friend, he showed the computer. I asked him to start it so I could record a video of the error. To our surprise, the machine started directly into its HP-UX 5.0 UNIX system stored in ROM. Maybe the reseating of the internal boards helped it. Who knows. Anyway, we haven’t played with it more. I will first clean it and it is necessary to check capacitors in the power supply, repair the power button and check why the machine does the high-pitch sound when operating – it sounds like a hard drive which is not there.

I love how the machine looks like and it is even smaller than I expected. When carried, it is just as tall as my 1989 Toshiba T3200SX with a 386SX CPU, 3MB of RAM and a VGA gas-plasma display… and it is not much heavier. HP Integral Personal Computer is based on the Motorola 68000 CPU and has at least 512KB of RAM. In addition to the ROM storage containing the operating system, there is just a single internal floppy drive (720KB 3.5”). More storage devices can be connected using HP-IB though. I always wanted this machine. I even have a HP Journal magazine from 1985 with a very in-depth description of each internal component.

SGI Indy CMOS Battery Fix

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Replacing a dead CMOS battery in a Dallas NVRAM/clock chip without using proper tools. This was for our precious Silicon Graphics Inc. Indy UNIX workstation.

Shark demo (1994) running on a SGI O2 workstation

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This is one of the demos that were used by Silicon Graphics and Nintendo to show the graphics features of their upcoming game console (Project Reality / Ultra 64 / Nintendo 64) during CES in 1994.

SGI used an Onyx supercomputer to run the demo. I recorded it in 1024×768 (true-color) on a much less powerful SGI O2 workstation (released in 1996). O2 is based on a graphics architecture similar to what was actually used in Nintendo 64. It was a perfect fit for an inexpensive highly-integrated computer as well as a game console.

I would rather use a different SGI computer (Octane2 was my first choice), but O2 was the only machine that was compatible with my cheap VGA-to-HDMI converter.

Preparing my SGI Indy for a vintage computer event

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Bytefest 2019 is coming and I have only two weeks to prepare all the machines I want to take with me. I want to the show this Indy with a Nintendo 64 game console because Indys were often used for N64 game development (after all, N64 hardware was designed by SGI). It is nice to see that Indy’s VINO interface supports progressive scanning (used by game consoles and old 8bit computers) on its composite/S-Video inputs – unlike newer SGI O2 and SGI Visual Workstation 320. Anyway, the main planned part is to connect a vintage Czechoslovakia plotter (Aritma Minigraf) using our custom interface (modified to use a serial port) and plot processed images of visitors taken using the Indy’s bundled webcam.

I’m surprised that serial ports on Indy support speeds only up to 38.4 kb/s. Pretty slow for a computer introduced in 1993. Maybe that’s one of the reasons why the serial port speed was not even mentioned in the user guide. They just didn’t care.

Dead DEC Multia… any ideas?

I was given a Multia a few months ago from a former Digital employee. He told me that the machine could not start (no sign of life, even fan didn’t spin on). I cleaned it, checked all cables and the machine started without any issue. However, after an hour of work, screen went black and the machine was not able to boot anymore (no smoke effects).

I thought this was maybe the well-known issue with the two chips on the bottom side of the system board dying due to overheating. Ordering these chips looked easier than doing any diagnostic so we ordered the replacement and “fixed” the board. However, it didn’t help. My Multia still blinks the error code E – “Failed while configuring memory”.

These chips are octal bus transceivers – they are between the CPU and RAM slots. There are nine of them (8x8bit for data, 1x8bit for ECC). Two of them on the bottom side. We did some checks using oscilloscope to see what was happening there. At least OEAB signal was changing rapidly. !OEBA seemed H all the time (cannot tell for sure, maybe there were just too few changes). There was some data on two out of the nine chips. The rest of transceivers had no visible data receiving from the CPU (L).

We don’t have a usable logic analyzer at the moment so it is hard to move further. I tried to find some documentation and block diagrams of the machine with no success (I have a reference board design for the CPU though). Also, all Multia pages just mention that there are issues with the two transceivers that we already replaced… but there is no further explanation how the machine behaves if these are faulty (to check that we are on the right way).

Any ideas what to do next? Burn it with fire?

DEC Multia Restoration #2

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In the first part, I cleaned this little machine and convinced it to boot. Sadly, it died an hour after the first start. Anyway, you can see photos containing:

  • Video card self-check (color stripes)
  • ARC firmware for loading Windows NT (blue background)
  • SRM console integrated in the firmware for booting UNIX and VMS (black background) … yes, it has dual firmware
  • Digital Tru64 UNIX boot
  • CDE graphics environment

Today, I will try to replace two suspicious chips. Let’s hope that it will bring the machine back to life.

DEC Multia Restoration #1

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Multia (1994) was the smallest Alpha-based computer made by DEC. It was intended as a low-cost workstation but never was really successful. One of my colleagues, a former DEC employee, gave me this machine in a non-working state and – being my first and only Alpha-based system – it deserved to be fixed.

I’ve completely disassembled the whole computer and cleaned every single component inside to get rid of dust and ugly mold smell. Minor issues were found and easily fixed. There were some partially disconnected cables which probably caused that the system didn’t want to boot when was found again in storage by the original owner.

Multia was incredibly small even by the office PC standards back then. DEC managed to squeeze a 64-bit Alpha CPU, enough RAM slots, 2-MB 2D graphics accelerator, Ethernet controller, IDE interface, PCI slot and two PCMCIA slots (bottom side) on a small mainboard. The hi-end configurations (like this one) were offered with a small PCI riser containing a SCSI controller chip combined with a 3.5-inch SCSI hard drive filling the last empty space inside the case. As a result, these configurations overheated significantly.

Trancept Systems TAAC-1 (1987)

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TAAC-1 is an interesting and little-known piece of history. Its creators call it the first board-level GPGPU (a programmable graphics card). This thing was designed to accelerate scientific and medical visualization. It could render 30,000 3D Gouraud-shaded and Z-buffered polygons per second. In addition to that, it could also be programmed to accelerate volumetric rendering and ray tracing. The board could even be programmed in C and allowed to do more than just graphics.

The large double-plane VME board filled three slots and a half of it was covered with memory chips. There were 8MB of frame-buffer memory and the 200bit GPU logic ran at 8MHz, producing up to 1024×1024 pixels in true color. TAAC-1 was used with Sun 3 systems based on Motorola 68020 (16.67MHz).

Trancept Systems Inc. was founded in 1986 by three people. One of them was Tim Van Hook. The same person that later worked for SGI as a Principal Engineer (the architect of Nintendo 64) and started a company called ArtX (Nintendo GameCube graphics hardware), which was acquired by ATI in 2000.

Demo video: part1, part2
More info: virhistory.com, obsolyte.com