ST536 - Build in progress

[HomeLate]

SMD parts finished... I hate soldering those PLCC sockets :roll:

20240207_211556.jpg

[zChris]

Nice setup with the camera. Which model is it ?

[HomeLate]

That's a stereomicroscope (SM-4TP) with a 4k camera. I only use the camera to inspect my work.

[HomeLate]

Build complete. But ST boots with a white screen, which (probably) indicates a rom issue.

I had trouble burning the TOS 2.06 image from the TF536 site on a HN27C4096. After fidling the rom in the PLCC-2-DIP adapter, the rom was recognized and I could burn the rom in Xgecu.

The Xilinx programmed without any issue in ISE 14.7 (on an old XP box). I have to check the solder bits again under a microscope.

[HomeLate]

Well, I made big progress today.

First, one of the wires of my Xilinx programmer was somehow defective. Weird enough ISE never reported an issue and I assumed the CLPD was programmed succesfully. To rule the CLPD out, I checked the CLPD with a RPi and it was empty. This time I programmed the CLPD with the RPi and I had communication errors with the same cable. I made a new cable and voila, the CLPD was programmed and verified.

Next the rom. The HN27C4096 programmed without issues. Either byte swapped or not, I still had a white screen. I ordered some AT27C4096's and these arrived today. I programmed the byte swapped image with the TOS 2.06 (TF536 version) and EmuTOS. This time: succes! It booted right into TOS 2.06. After bank switching it also booted into EmuTOS.

After running some apps, the ST crashed. Keyboard nor mouse were working but I was still into TOS desktop. I rebooted the machine and it got stuck in TT-RAM check. Cold or warm boot, it locks up when it wants to test TT-RAM.

I'm going to check the solder joints again because I suspect it's a bad joint and a heat issue.

20240214_194915.jpg

[PhilC]

It could also be that your CPU isn’t up to the task of running at 50mhz. You will definitely need a heat sink if you’ve not already fitted one.

[HomeLate]

It could also be that your CPU isn’t up to the task of running at 50mhz. You will definitely need a heat sink if you’ve not already fitted one.

I think it should be but I'm not sure. I have one running for ages, in a Blizzard MK IV, stock without heatsink at 50Mhz. I wanted to test the cpu in the Blizzard but I can't get it out of the socket :?

Anyway, I shelved the project for a few days to work on my STE. I will pick it up again in a few days.

Unfortunately it doesn't fit in a ST without modifying the case. Would the Mega ST a better option? I only have a ST and a STE. I haven't got a Mega ST yet.

[PhilC]

@HomeLate yed it should work in a Mega ST but you’d need some headers to lift it above some of the existing components.

[HomeLate]

@HomeLate yed it should work in a Mega ST but you’d need some headers to lift it above some of the existing components.

Ok, so the hunt for a Mega ST will begin in the near future ;)

[HomeLate]

It could also be that your CPU isn’t up to the task of running at 50mhz. You will definitely need a heat sink if you’ve not already fitted one.

You were right about the heatsink. Yesterday evening it worked again. This time it ran without any issues during some GB6 benchmarks.