3 October 2020 meetup

Another great event was hosted by Gary at his man-cave. Brett, Rob and Gary were there and Andy joined us through the video call from Canberra.

Always good to catch-up with everyone and hear what has been going on with their retro projects and life in general.

I took along some Atari STM1 mice that had issues and were in pieces ready for fault-finding. I also took along an STFM board which I have fitted an Exxos ForgetmeClock II RTC wired to the cartridge port to show off.

Brett bought along his upgraded 600XL along with a tiny TV to connect the 600XL to for video output. Brett powered up the 600XL which had a cartridge inserted with a Flash card loaded with 8 bit software. Brett has been busy again porting his strip poker game with Kimberly in onto the 600XL. He loaded this up to show it working. Lack of sprites was a constraint on his coding the game but it looks very good and Kimberly was there blinking at us as the cards were dealt.

Brett also mentioned that he has recently acquired an Acorn Archimedes computer in a non-working state. After some working with it, he has managed to get ti to partially boot up and will be continuing the work this weekend to see if he can fully repair it. He has also been playing with the RISC OS on his Raspberry Pi to get accustomed to this operating system and how it works to help with repairing the Archimedes. Will be good to hear how this goes.

Andy then joined us via the video call from Canberra and this was the first meetup he has attended since moving from Queensland so it was great to see him looking well. He had been out and about on his new motorbike before joining us. Andy has been using his Raspberry Pi 4 and Retropie so he powered it up. He had it hooked up to a projector so we could see the screen through the call and it was just like being there. After a bit of playing to get everything plugged into the Pi, he eventually got R-Type II up and running and we watched him playing the initial level. I am now going to have to my Pi out and load up Retropie as this has changed a lot since I last used it and looks really good.

Andy had his Amiga 2000 sat in the behind him playing his music in the background. Good to see he has this up and running as he still has not unpacked his Falcon’s yet. He said he needs to confirm how to wire up the CT60 header again to get his main Falcon up and running.

We then moved onto the Atari STM1 mice Gary and I have that were not working fully. We tested the cable continuity to confirm that all the 8 wires were good from end-to-end to rule out broken wires as the cause of the lack of functionality. After test 2 of my mice cables and confirming they were good, we then moved onto testing them to see what was not working.

Both mice had issues where the mouse pointer would move in 3 directions but not the fourth. Once mouse did not move down and the other did not move right. I have purchased some sender-receiver LEDs and some LM339 IC chips as these are used in the directional logic on the mice boards. As the mice were moving in 3 directions, we worked on the assumption that the LM339 was working and so we replaced the yellow LEDs in the mouse that was not moving down one at a time. There are 2 yellow and 2 red LEDs on each scroll wheel. On these 2 mice, the red LEDs are impossible to remove without totally disassembling the ball plastic housing so we opted to try replacing the yellow LEDs first.

I had brought along my de-soldering gun which sucks the solder away and we used this on the mice to remove the LEDs and ICs. After replacing the first yellow LED there was no improvement so we replaced the second yellow LED and hey-presto the mouse now moved in all 4 directions again. Each set of red-yellow sender-receiver LEDs controls one direction so working on this information we only replaced one yellow LED in the second STM1 mouse and this fixed this mouse. These 2 mice both had the same internal PCB and components. I would like to give a shout-out to Paul and say thank you as the information he provided to buy these sender-receiver LEDs. I purchased them from Core Electronics in Australia so delivery was quicker than from overseas.

One of my fixed STM1 mice had the LM339 chip in a turned pin socket which was handy for the next mouse we worked on. Gary had one that was not moving in any direction at all but the mouse button was working fine so it had power. Brett and Gary tested the cable continuity to make sure that the cable was okay and it tested fine.

We took a guess that no movement indicated that the LM339 chip may not be working. We removed the chip and put it in my now working mouse with the IC socket. Sure enough, the mouse movement then stopped working so the LM339 chip was faulty/dead. We soldered in a new LM339 chip into Gary’s STM1 mouse and movement in all directions was restored. Gary has some sender-receiver LEDs he purchased from Best Electronics which were colour coded black and red but we were unable to get the black ones working when replacing black or yellow LEDs in the mice. These will need testing (if anyone knows how to test them, please let us know).

We then looked at another couple of my STM1 mice but these have sender-receiver LEDs with smaller plastic heads and the new ones I had were not a match so we could not get these working. These have been put aside for a later date. Gary then found another STM1 mouse that he had which had the same internals as the first 2 we had fixed. This also had movement in 3 directions only. After replacing one yellow LED the movement that was not working returned but it lost movement in the opposite direction so we replaced the second yellow LED and this fixed movement in both directions so we had a fourth working STM1 mouse.

After the success with fixing these mice, we then moved onto Greaseweazle’s and I gave an F1 Greaseweazle to Brett to test dumping his floppy disks.

Gary has a Blue Angel 69 game disk which was not booting in a real STE and the program in the auto folder would not run so we decided to re-write the disk with a working image. Before this we took an SCP dump of the disk. Gary had a few downloaded copies of the game and so we used HxC Emulator to convert these to an SCP format which we then used his Greaseweazle to write back to the disk. Whilst the updated disk booted on his STE, it did not fully load. The SCP conversion loads fine in Steem emulator so I need to look more into this as we have found previously, the Greaseweazle was not able to write back another game at a previous meetup and this is a limitation in the Greaseweazle itself. There are some SCP dumps that it cannot write back correctly.

We updated Gary’s F1 Greaseweazle to the latest firmware (v0.21) and also update the laptop software including the GUI and tested this was all working by dumping a floppy disk.

Another fun day catching up and I would like to thank Gary for hosting us.