ChrisS is trying to build a H5C1

[Steve]

@Oldskool I think with regular TOS you need to be running NVDI to have blitter working, I *think*.

[Badwolf]

So ST with onboard 192k ROM decode but using my ROM decoder for TOS 2.06 with blitter and altram enabled?

Hmm This isn't a configuration I've personally tested, to be honest, so there may be a bug.

The only difference is the tos decoding (glue vs dstb1).

Perhaps the decoding only works fron the 68k side (ie. the blitter access isn't properly decoded)? I'd need to look at the verilog.

I only powered up DSTB1 for the first time in over a year at the weekend and I realised I'd forgotten half of how it works! :lol:

With altram the behavior is comprable (so screen errors).
With altrom I get 4 bombs when the blitter is activated.

AltROM was always a bit of an experiment, it's amost certainly not tested with a different on-board glue ROM range, but the black smudges under menus and the like does sound like tos decoding isn't happening for off-board access.

You say it works with EmuTOS, would this be a 192k EmuTOS, perchance?

BW

[Badwolf]

@Oldskool I think with regular TOS you need to be running NVDI to have blitter working, I *think*.

Other way around. NVDI doesn't use blitter at all in its routines, hence why it's needed for TT-RAM adapters on the Falcon (DFB1, CT60 etc.) where TOS4 *always* uses the blitter.

BW

[Badwolf]

@Oldskool, yeah, the 2.06 decoding only looks like it works on access from the CPU side, so this behaviour is what you'd expect, I'm afraid.

Only triggering decode on AS_INT (the CPU-side):

https://github.com/dh219/DSTB/blob/main ... 68k.v#L112

And no reference to the TOS decode on the external DTACK:

https://github.com/dh219/DSTB/blob/main ... 68k.v#L157

So yeah, I'm afraid this particular combination won't work just yet. If you're happy to reflash firmware we can try an experimental fix later on?

BW

[Oldskool]

Hi @Badwolf,

Thanks for all the Github projects!
Already had the PCB for the DSTB-1 laying around for a longer time as I now own the Phoenix board I had no excuses any more for not building it (and the youtube guide is very helpful). A 68000 booster with Altram is in my mind the correct upgrade for a plain ST (who needs a Pi or 030 or FPGA..... :)).
The dual rom installed has 2.06 and 1.04. 1.04 works correctly indeed. 2.06 decoded by the DSTB-1 works however don't touch the blitter.
Emutos was loaded from floppy on top of 2.06 or 1.04 so not from Rom.

Next step is an internal HD solution. Have a spare PicoPi so am following that one also closely.

Yes sure I have a aliexpress USB cable for flashing firmware so that's not an issue.

[Badwolf]

Thanks for all the Github projects!

No worries!

Emutos was loaded from floppy on top of 2.06 or 1.04 so not from Rom.

Aha, that makes sense -- it was executing from RAM throughout so no decoding issues.

Yes sure I have a aliexpress USB cable for flashing firmware so that's not an issue.

OK. I can't promise it'll be in the next day or two, but I'll drop you a shout on here when I've had a chance to try a tweak.

BW

[Badwolf]

@Oldskool,

Give this a try? It's coded blind (don't have any hardware to hand), but let me know how you get on if you can.

BW

[Oldskool]

Hi @Badwolf,

You don’t need glasses even blind this seems to work.
So blitter can be activated.
Altram works.
Altrom however seems to bomb out when the blitter is activated.
Maybe this is always the case even on your STE?

[Badwolf]

Hi @Badwolf,

You don’t need glasses even blind this seems to work.
So blitter can be activated.
Altram works.
Altrom however seems to bomb out when the blitter is activated.
Maybe this is always the case even on your STE?

AltROM was really a bit of a throw-away gimick. If it works for you, grand, if not, sorry, but it's not really fully tested. :)

I suspect I'd basically need to apply some of the changes done here to the AltROM logic too.

But sounds like progress! :thumbup:

BW

[Oldskool]

@Badwolf

Found some issues

1
Because I would like to try the S2 midi module I installed scummvm ST with the Fate of Atlantis.
It seems that when using altram scummst crashes (in various ways when there is HD activity).
I’m not sure if this is a scummvm ST or a hardware issue. (however scummst should support and run from altram)
Also tried it under Emutos. Same result.
As harddisk I used an Ultrasatan. (So it could also be a DMA thingie.)
Without altram ScummST works. (and yes the S2 works).
Don’t have IDE so can’t try that.

* Seems to be an Acsi - Altram issue after some more testing today causing file corruption and read issues.

2
Under TOS 2.06 altram and blitter works however sometimes when the blitter is enabled I see some screen defects.
Mostly missing pixels.