Toshiba T5200 - RAM

[SpidersWeb]

I have killed a T5200 just from man-handling -likely a cracked trace - so I'm really hesitant about recommending anyone whip them open and start soldering lol
I guess in fairness that was only one machine but it's so hard finding replacement bits :/

Neo - you could try it, but I get a feeling there would be weird issues, hopefully someone else with more experience using those boards can post up. I'm sure somebody has made a 386->486 ISA upgrade board though.

With regards to the crystal, that 32 seems like a good sign, I'm thinking 32 / 4 = 8Mhz ISA bus, so potentially a separate clock for the CPU? Not really my forte but I wondered if there was two crystals or one earlier on.

 

[Neosodium]

Well, me and a friend who is better at soldering than me tried it out and installed extension pins where the crystal was so it could be swapped out - assuming the 80mhz crystal isn't dead (no way to test) something crucial must also rely on that crystal being 40mhz as the system did not boot with the 80 in there (blank screen, no HDD access)

It's possibly the chip to the left of the CPU (memory controller?) that states it runs at 20mhz and may not like to be run at 40, but I don't know. I will try a 50mhz crystal at some point to see if I can bump it up to 25mhz without any issues.

 

[Neosodium]

Update: The component that doesn't like running at 40mhz appears to be the CPU cache controller. I'm going to see if it will tolerate 25mhz but I'm guessing it's quite picky and because it uses the same clock as the CPU it's probably more hassle than it's worth trying to isolate it.

It simply does not start up when fed with 40mhz, is there a chance it could overheat if it does start on 25?