exxos's Atari, Amiga & retro forum

Ok, may add that to a board here and see if it gets my mega st running

exxos wrote: 14 Jul 2020 16:33 @agranlund Aside from "ROM in RAM". Have you any idea why its not installing alt-ram ? Thats the main thing I want to get running so I can get some CPU's at 50MHZ while doing TT-RAM tests..

Is EmuTOS able to find and install it correctly?

Give me a moment and I'll build you a stripped down version of maprom that only does the alt-ram parts and skips the rom/ram relocation.

agranlund wrote: 15 Jul 2020 08:29 Is EmuTOS able to find and install it correctly?

Give me a moment and I'll build you a stripped down version of maprom that only does the alt-ram parts and skips the rom/ram relocation.

I've not tried emutos yet. Would be useful just to have the ram installer. :thumbup:

exxos wrote: 15 Jul 2020 09:05

agranlund wrote: 15 Jul 2020 08:29 Is EmuTOS able to find and install it correctly?

Give me a moment and I'll build you a stripped down version of maprom that only does the alt-ram parts and skips the rom/ram relocation.

I've not tried emutos yet. Would be useful just to have the ram installer. :thumbup:

Sure thing. You can use this one: It only detects and installs fastram - no relocating of anything and no general MMU setup.
It's limited to maximum 64MB to prevent potential weirdness with current firmware, but of course I can't test that on my 4MB card :)

I would definitely start with EmuTOS though. It's more of a sure thing compared to tricking TOS2.06 into stuff it only partially understands :lol:

I'd recommend disabling the cache in TOS2.06. It doesn't flush it after DMA operations and that could cause weird floppy related stuff. We're lucky it has most 030/Fastram support of TOS3.06 even though it would have been pointless at the time, but it's a little bit weird that part was left out.
I guess it must have been a shared code at some point and then branched out to 2.06 for the 68000 machines and 3.06 for the TT?



If you have a blitter, you want to run blitfix.prg to prevent bad graphics in the best case, and blitter trashing the wrong memory in the worst case..
TOS itself is generally fine when it is executed from ROM, but if you're running it from RAM you absolutely need blitfix if you want to see the desktop properly.
But even with TOS in ROM and only fastram enabled, you'll get corrupted icons in the the "GEM Dialog Box" test in Gembench if the blitter is enabled and you're not running blitfix.


Of course, to be 100% safe you should probably just remove the chip completely.

In practice though, TOS and GEM applications should be fine with blitfix.prg.
Games/Demos can't really run from fastram anyway, at least not until we've solved somehow tricking their screen- and sound- buffer(s) into ST-RAM. So these can use the blitter all they want.
The ones that can run from fastram, like Frontier, are aware of the concept already so shouldn't have any blitter issue - most likely they wont use the blitter anyway since there never was an Atari with both fastram and blitter.

Why don't we just use TOS 3.06 then?

May be we can test TOS 3.06 with the PAK patches and load it from HHD or Floppy. Use TOSPATCH from Markus Heiden ...

DoG wrote: 15 Jul 2020 10:44 Why don't we just use TOS 3.06 then?

DoG wrote: 15 Jul 2020 10:44 Why don't we just use TOS 3.06 then?

I think that's what the PAK accelerator is doing, using a modified version of 3.06.
Probably less trickery involved going in that direction.

May need to patch the blitter available/enabled functions if that TOS doesn't understand what a blitter is?
The BLITB demo for example. Even though that demo does direct hardware access to the blitter, it's too polite for its own good in that it wont use it if TOS claims it isn't there..

That TOS is larger than 2.06 as well and I'm not sure enough signals are going to the ROM slots on the motherboard as-is?
PAK has their custom TOS3.06 onboard the accelerator card if I'm not mistaken?
But loading it from disk into ram could be a possibility, especially so now with 64MB RAM available.


I really think EmuTOS is the way forward though.
At the very least it's one TOS that supports many different configurations and it's in active development, rather than the three very old and different branches of Atari TOS tailored for specific models.
It doesn't require much trickery to load EmuTOS from disk into FastRAM either. It can be compiled into a .PRG for this purpose.

Saying that, 2.06 in fastram works fine for me on the TF534 (except for the floppy issue I didn't know about :lol:)
I almost exclusively using EmuTOS though.

@agranlund Thanks!! thats got the thing up and going now!


So GB6 running with and without blitter... ( I see what you mean about the first test when the blitter fix isn't ran now ;) )

I've turned off Data cache.. not much difference but alt-ram has gone up a bit in speed!

what is it compared to a standard st? 605% cpu?