It's no more a MiSTery

[sebdel]

Are you sure it never exits from that loop?

No I'm not, I'm just stepping through it in Hatari and guessing. This is not going anywhere, I will try a different approach.

[slingshot]

Are you sure it never exits from that loop?

No I'm not, I'm just stepping through it in Hatari and guessing. This is not going anywhere, I will try a different approach.

If you want to also check on FPGA, I can send you the .stp file I used last time to watch "breakpoints". But hardware debugging is a very tedious, time-consuming and hard job. No wonder why nobody ironing out the last bugs in cores. Better to have test suites or write small test programs, but then you must know what to check.

[sebdel]

No I'm not, I'm just stepping through it in Hatari and guessing. This is not going anywhere, I will try a different approach.

If you want to also check on FPGA, I can send you the .stp file I used last time to watch "breakpoints". But hardware debugging is a very tedious, time-consuming and hard job. No wonder why nobody ironing out the last bugs in cores. Better to have test suites or write small test programs, but then you must know what to check.

In this particular case I could unpack the .prg so I can patch it. I will add "color stops" like this:

Code: Select all

stop: move.w $700, $8240.w
	bra stop

I should find where it loops eventually.

[slingshot]

Code: Select all

stop: move.w $700, $8240.w
	bra stop

I should find where it loops eventually.

Clever trick.

[ijor]

... DMA and the Shifter don't even have a reset pin

All the custom chipset has hardware reset, including DMA, Shifter and ST MMU. You don't necessarily need a reset pin. They perform reset when they detect some external signals are in a condition that can happen only during Reset. Shifter, e.g, resets when both LOAD and CS are asserted at the same time. Can lookup the others if you are interested.

Did you know the MegaSTE external keyboard doesn't have the reset line, so ikbd reset doesn't work there?

Yes, this is well known. Any software that depends on the IKBD reset signal won't work on the Mega. Not just the MegaSTE, but the MegaST as well.

Btw, great work on MiSTery!

[slingshot]

... DMA and the Shifter don't even have a reset pin

All the custom chipset has hardware reset, including DMA, Shifter and ST MMU. You don't necessarily need a reset pin. They perform reset when they detect some external signals are in a condition that can happen only during Reset. Shifter, e.g, resets when both LOAD and CS are asserted at the same time. Can lookup the others if you are interested.

Now I know why the GSTMCU asserts CMPMCS_N and DCYC_N together at power-on. Would be interesting to know the other combinations, even if it's already a reset signal for most of the chips.

Did you know the MegaSTE external keyboard doesn't have the reset line, so ikbd reset doesn't work there?

Yes, this is well known. Any software that depends on the IKBD reset signal won't work on the Mega. Not just the MegaSTE, but the MegaST as well.

Btw, great work on MiSTery!

Thanks! Just if Closure would work in ST mode...

[ijor]

But hardware debugging is a very tedious, time-consuming and hard job. No wonder why nobody ironing out the last bugs in cores.

I think it is relatively easy as long as you can use a software emulator debugger to compare the traces It is several orders of magnitude harder when for some reason you can't.

Now I know why the GSTMCU asserts CMPMCS_N and DCYC_N together at power-on. Would be interesting to know the other combinations, even if it's already a reset signal for most of the chips.

For MMU is both DEV and RAM asserted at the same time.
For DMA is CS asserted for more than 16 cycles.

[slingshot]

But hardware debugging is a very tedious, time-consuming and hard job. No wonder why nobody ironing out the last bugs in cores.

I think it is relatively easy as long as you can use a software emulator debugger to compare the traces It is several orders of magnitude harder when for some reason you can't.

True. Btw, I miss some raster position indicator from ST emulators. It was nice in WinAPE, the CPC emulator.

For MMU is both DEV and RAM asserted at the same time.
For DMA is CS asserted for more than 16 cycles.

Oh yeah, FCS_N is asserted at reset for this reason then. I wonder if it can be triggered in software. I think the CPU won't select the DMA chip for 16 cycles.
And even MMU is integrated, RAM_N and DEV_N also going to low during reset.

[ijor]

Oh yeah, FCS_N is asserted at reset for this reason then. I wonder if it can be triggered in software. I think the CPU won't select the DMA chip for 16 cycles.

It's not up to the CPU. It's actually up to the DMA chip itself depending on how many wait states it would produce on an access. But no, I don't think it would happen even in the worst case.

[slingshot]

It's not up to the CPU. It's actually up to the DMA chip itself depending on how many wait states it would produce on an access. But no, I don't think it would happen even in the worst case.

Yes, but it's not really software-triggerable (I was just speculating if it would be possible to reset the DMA via software - not by changing the direction bit, which does reset the FIFOs in the current implementation).

[ijor]

It's not up to the CPU. It's actually up to the DMA chip itself depending on how many wait states it would produce on an access. But no, I don't think it would happen even in the worst case.

Yes, but it's not really software-triggerable (I was just speculating if it would be possible to reset the DMA via software - not by changing the direction bit, which does reset the FIFOs in the current implementation).

I think I did understand what you meant. You meant if software could somehow provoke the CPU/GLUE to assert DMA chip select for more than 16 cycles, right? What I meant is that if something like that could be possible or not, it depends on how many wait states the DMA chip inserts (indirectly thorugh GLUE) on a bus access.

[slingshot]

I think I did understand what you meant. You meant if software could somehow provoke the CPU/GLUE to assert DMA chip select for more than 16 cycles, right? What I meant is that if something like that could be possible or not, it depends on how many wait states the DMA chip inserts (indirectly thorugh GLUE) on a bus access.

I think we can agree on this. It depends on how many cycles after FCS_N DMA asserts RDY. It won't be 16 cycles in any case I guess, so no software will depend on it - no problem if this kind of reset is not implemented.

[sebdel]

Code: Select all

stop: move.w $700, $8240.w
	bra stop

I should find where it loops eventually.

Clever trick.

Just a quick update on this: I progressed far enough that I could see weird usage of trace vector but then I had to pack my Mist as we are renovating the house. So no more mist for me until at least Xmas I reckon.
Then out of nowhere leonard had a look at 0913 for completely different reasons and apparently this music disk has a protection against ripping, you can read more here: http://www.atari-forum.com/viewtopic.ph ... 25#p386003
Sooo, maybe the trace vector decoder is not working? I don't see why it would not but that looks like the most likely explanation now.

[slingshot]

I don't think such bug exists in the CPU. It's more like a timer doesn't switched on after the loading (MFP), or the disk DMA and blitter DMA are conflicting (might be some events don't happen at the right time during DMA). It's hard to tell without digging into it deeper, and I don't want to do it until we have an accurate blitter.

[jamesrc]

For reasons I don't completely understand, the HIPSid disk/demo doesn't work properly on my MiST.

It starts correctly, but if you select a different music track it never starts to play. The UI continues to be responsive.

http://www.pouet.net/prod.php?which=70807

This was a problem with the old core, too.

I'll go add to the Github Demos issue.

[slingshot]

Well, that long discussion with sebdel was about that. However it's an STe demo (but not sure if the bug is STe specific).
Ah, I see it's a different demo with the same bug (same play engine?) - maybe easier to debug.

[jamesrc]

Well, that long discussion with sebdel was about that. However it's an STe demo (but not sure if the bug is STe specific).
Ah, I see it's a different demo with the same bug (same play engine?) - maybe easier to debug.

I should have reread the other conversation because I did wonder if it was related.

It's not an STe only demo -- it works fine on an STFM, too.

[slingshot]

Is there any game/test/anything which uses the analogue paddle connected to the STe joystick ports?

[Televicious]

Is there any game/test/anything which uses the analogue paddle connected to the STe joystick ports?

Only things I found that support EJP's analog were made for Falcon.

[slingshot]

Only things I found that support EJP's analog were made for Falcon.

Then not much value of adding support. Cannot even test it.

[slingshot]

For reasons I don't completely understand, the HIPSid disk/demo doesn't work properly on my MiST.

II'll go add to the Github Demos issue.

Good news, it's fixed (also the other STe demo disk works).

[jamesrc]

For reasons I don't completely understand, the HIPSid disk/demo doesn't work properly on my MiST.

II'll go add to the Github Demos issue.

Good news, it's fixed (also the other STe demo disk works).

If you're ever in Texas, I'll buy you a drink or five.

THANK YOU!!

(Quick edit: I don't see any recent commits to your repo, so am I correct in assuming you've not pushed these changes yet?)

[slingshot]

(Quick edit: I don't see any recent commits to your repo, so am I correct in assuming you've not pushed these changes yet?)

Not yet, there are some other surprises waiting. I'm afraid I'm too far away for some beer from Texas - but would be good, thanks

[jamesrc]

Long weekend here in the States.

Being British, I have no great nostalgic attachment to Thanksgiving, but I'll take the four days off and the meal.

Might be an opportunity to continue my slog through those PoV disks...

[slingshot]

Long weekend here in the States.

Being British, I have no great nostalgic attachment to Thanksgiving, but I'll take the four days off and the meal.

Might be an opportunity to continue my slog through those PoV disks...

Good idea, you might report if you found some bugs.
Meanwhile I fixed POV7 Pro Replay.
Hope I can upload the sources soon (but the git version will require a firmware update for ACSI - however it's not required for floppy demos).