ST536 STE EDITION

[exxos]

I've just tried the no TT ram firmware and it still gets a stuck trying to boot ST536 tos but does boot to desktop now with EmuTos 1.2.1 and will see and format a floppy without issue.

ST,536 tos gets stuck here

That's odd by itself as sterm isn't issued as TTram isn't decoded. So TOS shouldn't find any TTram or try and test it :shrug:

I assume your cold booting between tests ?

[PhilC]

I've just tried the no TT ram firmware and it still gets a stuck trying to boot ST536 tos but does boot to desktop now with EmuTos 1.2.1 and will see and format a floppy without issue.

ST,536 tos gets stuck here

That's odd by itself as sterm isn't issued as TTram isn't decoded. So TOS shouldn't find any TTram or try and test it :shrug:

I assume your cold booting between tests ?

Yes tried cold booting and warm booting. Emutos doesn't detect any TT ram. Could this be a bug in ST536 tos?

[exxos]

Yes tried cold booting and warm booting. Emutos doesn't detect any TT ram. Could this be a bug in ST536 tos?

Possible... But when TTram has been not found at all on my machine , it doesn't even try to test TTram. I wonder if there's something screwy on your board somehow. Maybe check STERM never goes low as only TTram uses it... It shouldn't go low at all with the no TTram firmware..

[PhilC]

Yes tried cold booting and warm booting. Emutos doesn't detect any TT ram. Could this be a bug in ST536 tos?

Possible... But when TTram has been not found at all on my machine , it doesn't even try to test TTram. I wonder if there's something screwy on your board somehow. Maybe check STERM never goes low as only TTram uses it... It shouldn't go low at all with the no TTram firmware..

STERM stays at 3.3V the whole time.

[exxos]

STERM stays at 3.3V the whole time.

That's good then.. I'll have to look into TOS more on it's behaviour. But if no ram is there TOS shouldn't be testing it..

Have you run GB6 to make sure it's all stable otherwise ?

[PhilC]

STERM stays at 3.3V the whole time.

That's good then.. I'll have to look into TOS more on it's behaviour. But if no ram is there TOS shouldn't be testing it..

Have you run GB6 to make sure it's all stable otherwise ?

No, I ran out of geek time today and have been gardening every since, maybe tomorrow morning.

[Badwolf]

That's odd by itself as sterm isn't issued as TTram isn't decoded. So TOS shouldn't find any TTram or try and test it :shrug:

Is there a bus error handler on the TT-RAM to catch a missed assertion of STERM? If you're only not asserting STERM and not terminating the cycle any other way you'll get a hang on any TT-RAM-space access.

Safest way to stop TT-RAM working IMO is to keep the DQM lines high (or drive the CKE line low).

The firmware will still go through the state machine but nothing will get read or written so the detection will fail.

BW

[exxos]

Is there a bus error handler on the TT-RAM to catch a missed assertion of STERM? If you're only not asserting STERM and not terminating the cycle any other way you'll get a hang on any TT-RAM-space access.

Good point. Will look into that.

[PhilC]

With EmuTos 1.2.1 as I still can't be bothered toale another rom :lol:

It will happily run Gem bench, the below figures are without TT ram, maprom or blitfix obviously.

PXL_20250428_112356242.jpg

[exxos]

I "hit record" on my magnifier station and just showed how I got on resoldering the PLD...