exxos's Atari, Amiga & retro forum

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Play time this evening!

It's alive! (Sort of).
Testing with just 68000s at the moment.

The dual TOS switcher works perfectly. I can change between 1.04 and 2.06 using the jumper.

With one CPU in the Accelerator socket the machine works perfectly. With a second CPU in the 68000 socket it definitely needs an auxilliary power supply otherwise either it doesn't boot or you get random black pixels but boots to the desktop and can run Gembench 6 without a problem.

Switching the the 68000 socket the machine boots but for some unknown reason it can't see the keyboard! Everything else seems to work from what I can tell. What the heck?! Any ideas what this might be?

After the first time I plugged in the auxiliary power for some unknown reason the flash floppy drive doesn't want to work any more, but a normal floppy is fine. ????

I'm soak testing Frontier with a CPU in the Accelerator socket at the moment.

P.S. there seems to be more 50Hz noise on the audio channel than there was before.
P.P.S. Here's a close-up of the board and the auxiliary power connected.

stephen_usher wrote: 12 Oct 2020 19:17 Switching the the 68000 socket the machine boots but for some unknown reason it can't see the keyboard! Everything else seems to work from what I can tell. What the heck?! Any ideas what this might be?

Missing E-clock ? or VMA, VPA signals..

It turns out that the FF problem was a rubbish USB stick.

First test with the TF536 is that it works fine without the second CPU in the socket. Even ACSI works surprisingly.

exxos wrote: 12 Oct 2020 19:40

stephen_usher wrote: 12 Oct 2020 19:17 Switching the the 68000 socket the machine boots but for some unknown reason it can't see the keyboard! Everything else seems to work from what I can tell. What the heck?! Any ideas what this might be?

Missing E-clock ? or VMA, VPA signals..

Most likely the E signal as that's switched by the HCT157s and I've probably got a duff solder joint.

stephen_usher wrote: 12 Oct 2020 20:03 Most likely the E signal as that's switched by the HCT157s and I've probably got a duff solder joint.

I trust you do have E going the right direction through the mux? CPU sockets on mux input side, motherboard on mux output side.

Id been using mine by using the keyboard as a mouse without problem. Ill remove the second cpu and see if that help the TF536 work better.

Well, it does on mine:
I'm still running old firmware on the TF at the moment, and I've disabled the cache so that TOS 2.06 is happy.

Hmm... Looking at the clearances, to get this tower into the standard STFM case with the keyboard in place would require the TF to be directly soldered to the relocator board and the 68030 soldered directly to the TF PCB and even then it'd be a close run thing. The two sockets add about 1cm to the total height of the stack.

I can make the board about 4mm/5mm wider and shift the TF toward the PSU by a similar amount to give a little bit more clearance, maybe a couple of mm.

Ok, so ive been messing around a little as I can't remember where I put my gotek drive.

Anyway, with the TF536 in the 68000 socket it works great with or without a 68000 in the accelerator socket.

With just a TF536 in the left hand socket I get graphic glitches on the desktop and frontier crashes immediately.