Ticking along

First, let me lead by saying I’ve started a new job, so posting will drop down to a less regular schedule from here on out, I’m afraid.

I’ve been working on all sorts of projects without much success on many of them.

• The Amiga 1000: I’ve removed and socketed all the RAM. All the RAM passes testing in the Retro Chip Tester Pro, so it’s not that. Kickstart runs through to the point where it reboots but it never comes back to ask for Workbench. DiagROMs stop at the line “Parallel Code $fd – Start of chipmemdetection” and that’s it.
• The Creativision: This one has been a real challenge, but I am making progress. So far I have: socketed the key chips. Fixed the break I made socketing the chips. Patched countless Vias. (Many many of these have simply stopped conducting. Reflowing them resolves the issue, but I suspect they were never through hole plated.). Restored the clock signal for the CPU. Patched even more Vias.
  Curretnly the CPU has (finally) started running code. The GPU, however, is not getting a clock signal and the crystal itself isn’t oscillating so I need to do some more debugging there. There has been a lot of rework in that area and I wonder if someone has accidently put a component in the wrong place, specifically one of the inductors.
• BlueSCSI V2: I soldered up one of these, but it doesn’t work. Diagnostics seem to pass but it doesn’t actually work. I might just write this off as a learning experience and get on with my life.

Meanwhile I have had some wins!

Microbee CGA to VGA Adapter

Firstly, after a failed attempt I ran up a remix of Necroware’s MCE to VGA adapter, suitable for mounting inside a case with only the VGA port exposed. This is for a long term project of mine to design a new external enclosure for one of my Microbee Gotek drives. I’m basing it off the classic “Computer in a Box”

Microbee Computer in a Box

When I got this (See last post) I had replaced the Rifa caps, but when I checked the voltages, they were hovering dangerously close to 11V. Way too high for my comfort. Looking at how the voltage was being “dropped”, it looked like there was simply a bridge rectifier wired across the 12V rail from the PSU. I’m guessing some of the internal diodes had gone closed circuit, so the voltage drop was being lost.

As I had some on hand, I decided to use some buck converters I’d ordered. Much to my annoyance, neither of the pair I had ordered actually worked. Whaat? Anyway, a quick trip to Altronics and I had a replacement, albeit without the fancy voltage guide the ones I had got previously had. No great loss. That’s what multimeters are for.

I then carefully measured the dimensions of the case, fired up coreldraw, and lasercut a case from strawboard. This I covered in cloth (Salvaged from some old curtains), glued down with PVA and I had an enclosure to go around the inner case.

I’ve got a nice piece of artwork to go on the side of the case, but that’s a project for another day.

Amiga 1200 Casemod Front Panel

Another long term “blocker” on my A1200 casemod is complete. This is a custom board to bring the joystick ports from the back of the case to the front of the case. It also allows automatic switching from joystick to mouse, and allows me to use a PS/2 compatible USB mouse with the system. (There’s also a port for bringing the internal keyboard out to either PS/2 or PS/2 compatible USB as well)

I really need to “get back on the bicycle” on this project and start cutting again. It’s been stalled for far too long.

Mind you, I still haven’t even decided what colour to make the case. Torn between Bone and Piano Black.

Amiga PCMCIA CD ROM

I also discovered that the CD ROM that came with my Sony VAIO is actually Amiga compatible! Scooore!