exxos's Atari, Amiga & retro forum

wub wrote: ↑Fri Jul 29, 2022 11:05 pm If I run the new STe version of Lotus Turbo Challenge I get a couple of problems. The chip music will drop out after a while and not come back, while the samples carry on playing correctly. By this point the graphics on screen are starting to corrupt, a flashing line under each car that gets 1 vertical row taller each level, and the background has horizontal rows of corrupt data that get worse each level too.

Do you by chance have the STE with the integrated blitter, ie. U101 is unpopulated?

BW

@Badwolf No, my STe is the same as this one: viewtopic.php?f=51&t=4718

The only difference is that the link on the bottom is flapping around freely as it doesn't have the blobs of glue holding it to the board.

Do you have problems running Lotus Turbo STe too?

@exxos Thanks for the suggestion about replacing my CPU, I've looked at the ones you're selling and it sounds like a really good idea. I'll put an order in before the weekend!

wub wrote: ↑Tue Aug 02, 2022 8:34 pm @Badwolf No, my STe is the same as this one: viewtopic.php?f=51&t=4718

The only difference is that the link on the bottom is flapping around freely as it doesn't have the blobs of glue holding it to the board.

Do you have problems running Lotus Turbo STe too?

No, or at least I don't know: I'll be honest, I've not got around to trying it.

I was thinking it sounded a bit blitter-ish, and it put me in mind of a different issue.

Have you tried removing and cleaning the blitter chip itself, spraying the socket with contact cleaner and reseating a few times?

BW

If you haven't tried the special Lotus Turbo STe version you're in for a treat!

As for the chips, I found that they are all really tough to get out, so I let them be for now. I would have expected some sort of flaky behaviour, particularly when it warms up, if something like that was going on?

I like the idea of running a lower power 68k CPU so I'm going to give that a try anyway. If things are still not 100% then I may get brave and try re-seating everything.. I'd feel happier doing that if I had another spare ST to use if things go wrong!

wub wrote: ↑Tue Aug 02, 2022 9:25 pm I like the idea of running a lower power 68k CPU so I'm going to give that a try anyway. If things are still not 100% then I may get brave and try re-seating everything.. I'd feel happier doing that if I had another spare ST to use if things go wrong!

I was focusing more on the Lotus problem, but if the sound is knackered in Frontier too it's likely a different problem (or possibly two problems).

Good luck!

BW

Yeah, you're right. I wonder if that funky factory mod to the sound chip has something to do with it all..

Anyway, thanks for your advice!

Thanks to @exxos I now have a new 68k CPU installed and it has indeed fixed the corrupted graphics in Lotus Turbo STE!

I had it running for about 4 hours this evening and no problems showed up at all. The sound chip music still drops out after a while so I still have something funny going on but at this point I'm just going to get on with using it and see what happens. Half meg games seem to work fine so it might just be a weird 1MB STe hardware bug?

My first project will be to port a small Sam Coupe sound FX app to the ST and get my head around this yamaha sound chip so maybe something will come up.. either way, good call Exxos! I'm a lot happier with how this is working now

I suspect it stems from the pullups. I guess it would be interesting to try changing them with the original CPU to see if that solves the problems.

If it's just a case of buying some new resistors and swapping them in then I'd be up for having a go at that. It would be nice to understand exactly what's wrong and get it fixed 100% I'm just worried about making a mistake that leaves me without a working ST at all. When I have the funds available I'll get an STFM as a backup machine and revisit this for sure.

Thanks again!