Author: shelldozer

Hollywood or Dust: Episode 5 – Fashionable

[Repairing the PSU from an SGI Iris Indigo R3000] Reassembly After replacing damaged diode CR111, it's time to reassemble the PSU and give it a try. Reassembly is a bit easier than disassembly, but still very fiddly, especially getting all the spade connectors back where they are supposed to be. Needlenose pliers are needed, and … Continue reading Hollywood or Dust: Episode 5 – Fashionable

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Hollywood or Dust: Episode 4 – Vitamin E

[Repairing the PSU from an SGI Iris Indigo R3000] The postman has delivered my replacement 1N5352 zener diode (actually three of them, I figure this might take a couple of tries, and I might need another one for a subsequent repair in another 25 years). Vitamin E However, before wielding the soldering iron, I am … Continue reading Hollywood or Dust: Episode 4 – Vitamin E

Hollywood or Dust: Episode 3 – Just Another Sucker On The Vine

[Repairing the PSU from an SGI Iris Indigo R3000] Reboot After two weeks off from Retrochallenge due to other commitments, it is time to re-energise this project. I need to remove the obviously-broken diode CR111 from the large PCB, (a) to see which exact model of diode it is, so I can order a replacement, and … Continue reading Hollywood or Dust: Episode 3 – Just Another Sucker On The Vine

Hollywood or Dust: Episode 2 – Zarking Genius

[Repairing the PSU from an SGI Iris Indigo R3000] More Investigation In the last episode, I managed to extract one of the boards from the PSU and found it to be in superb condition. But what about the other, larger PCB? Although I could see parts of it "in-chassis", I really needed to remove it … Continue reading Hollywood or Dust: Episode 2 – Zarking Genius

Hollywood or Dust – Episode 1: Down the Rabbit-Hole

[Repairing the PSU from an SGI Iris Indigo R3000] Oops, Retrochallenge 2017/10 has been running for a week already - better pull myself together and make an actual start on my project! Peculiarly Special The Iris Indigo has a slightly complex PSU history and situation. The original Indigo, based on the MIPS R3000 CPU, uses … Continue reading Hollywood or Dust – Episode 1: Down the Rabbit-Hole

Hollywood or Dust

As is often the case with hardware this old, my 1991 SGI IRIS Indigo R3000 will not start. Well, that's not quite completely true... Symptomania: When pressing the power-switch, the fan did not spin, neither of the two SCSI disk drives spun up, the screen remained resolutely blank, and the cute Indigo power-on tune did … Continue reading Hollywood or Dust

The Return of The Thin

I have recently acquired an old HP T5510 32/128 "thin client" device - a dedicated remote-graphical-terminal, manufactured in 2004 (not my pictures, I'll get those up in due course): With the addition of a VGA monitor, USB keyboard and mouse, and an Ethernet cable, this device can connect to remote RDP and Citrix services. Well, … Continue reading The Return of The Thin

Cherryside Addendum #1 – Others Bodges

Although Retrochallenge 04/2017 finished a few weeks ago, I have carried on with my project, making some improvements to my PS/2 keyboard interface for the 68HC11 microcontroller. Expanded-Mode Compatible In particular, I now have the hardware interface working using only PORTA (pins 3 and 7, using the pulse-accumulator for the input-clock and the bidirectional-capable pin PA3 for … Continue reading Cherryside Addendum #1 – Others Bodges

With a Cherry on the Side – Lessons Learned (Dijkstra be Damned)

[A Project to interface a PS/2 keyboard to a 68hc11 microcontroller]This RetroChallenge project reached its' target - decoding, reading, and reporting PS/2 keyboard scancodes with a 68HC11 microcontroller using only internal resources (no external memory, no external I/O device controllers, no external logic, etc). I had picked a rather minimal project because I knew April would … Continue reading With a Cherry on the Side – Lessons Learned (Dijkstra be Damned)

With a Cherry On The Side – Episode Nine (Squinting Backwards)

[A Project to interface a PS/2 keyboard to a 68hc11 microcontroller] The Starting Situation By the previous episode, I was getting the right number of clock-pulses per PS/2 key event, but not all the scancodes received seemed correct, eg: Key Detected Scancode Expected Scancode Comment Q 0xA8 0x15 wrong W 0xB8 0x1D wrong E 0x24 … Continue reading With a Cherry On The Side – Episode Nine (Squinting Backwards)