STE - Possible DMA Issues

[matt.lacey]

So after replacing a bad ROM chip on my STE last year with TOS 2.06 (and recapping the PSU) it seemed to be running well, but recently I've had a few issues. I've been developing a game using AGT under Hatari, occasionally testing on the hardware. Everything was good until i got to doing the audio, I went for the DMA option because it's so easy, and it's working great under emulation, but on my STE the sound is fuzzy and distorted.

I've tried a few STE specific demos and they all seem to crash on load - and now I just tried running Gods and that too crashed - I'm 99% sure I've run the same .PRG in the past ok.

I thought my NetUSBee was playing up but I think it's actually the cartridge port, as the diagnostic cart also fails to boot a lot of the time ending up on a red screen with some garbage at the top. When it does run nothing seems amiss though - RAM checks out fine, blitter test works, and the DMA sound checks sound clean - I don't have a scope to test the waveform, but they sound like pure sine waves (or as close as the STE is gonna get) to me.

Not sure what the best path forward is from here?

[matt.lacey]

Well I reflowed the DMA chip and the cartridge connector. DMA sound in my game now sounds clean which is good, though Gods still crashes on me and I'm sure it was good previously.

[Cyprian]

nice,
btw. DMA chip is for ACSI/FDD data transfer not for DMA sound. That part is managed by MMU (GST MCU) and SHIFTER (GST SHIFTER)

[matt.lacey]

Heh, weird... I did give the only socketed chips a gentle push, maybe that did it?