TF536 EmuTOS and TOS2.06

[zChris]

When you are talking about the boot rom. What i imagine is that you have a chip with the bootrom modified onto it andd that replaces the TOS chip?

/zChris

@zChris Found the link I posted with the original files (including the 192k boot images from @agranlund...
https://www.exxosforum.co.uk/forum/viewt ... 627#p50625

So depending on whether you have a 2x ROM or 6x ROM setup you could program up some EPROMs & replace the existing TOS 1.x (6x ROM version is easy as you can then use 6x 27C256 EPROMs...with 2x ROM version you would need an adaptor to convert from 32 pin EPROMs to the 28 pin sockets - or change the links for the ROM size & use 6x EPROMs)

Do you know whether you have 2x ROMs or 6x ROMs in your ST at present?

I have 6 rom chip. Motherboard revision is C070789-001 REV.D

[Atarian Computing]

One cool thing I noticed with using @agranlund's custom 192K ROMs was that XBoot works in it. That way I can select MagiC without loading the 256K EmuTOS at all.

It's a really cool setup and works superbly for me on a STacy without a decoder.

[WiseGreasyBastard]

The normal 192k version might not be configured to support 020+ CPUs, the MMU, TT-RAM and so on.

My test board is a mega ST2 and the only mods to it are bus resistors changed for 2k2 and a socket for the CPU.
I expected it to boot with a 68000 cpu in the socket without needing anything other than W2, W3 and W4 changing over - is that not the case with emutos v1? Switch back to 2 chip tos 1.04 and it boots to desktop again.

As soon as my volt nuttery stuff has moved from the test bench I'll take a look at it.

[agranlund]

The normal 192k version might not be configured to support 020+ CPUs, the MMU, TT-RAM and so on.

My test board is a mega ST2 and the only mods to it are bus resistors changed for 2k2 and a socket for the CPU.
I expected it to boot with a 68000 cpu in the socket without needing anything other than W2, W3 and W4 changing over - is that not the case with emutos v1? Switch back to 2 chip tos 1.04 and it boots to desktop again.

As soon as my volt nuttery stuff has moved from the test bench I'll take a look at it.

Ah I missed that you had the same issue with the stock 68k cpu. In that case, I have no idea :)
I would check if you can get 6-chip tos 1.04 running first, to rule out one variable of the equation.

[zChris]

One obvious question i forgot to ask is why a modified EmuTOS is needed?

When i look at EmuTOS download i see versions 192, 256 and 512. And from what i have gathered they are suitable for different branches of atari. For Atari ST it is the 192 thats most suitable?

But it is not setup to work on CPU thats over 68000? Is that why it was needed to modify it to boot 256 version from floppy?

So basically the question is why EmuTOS does not work directly and must be modified to load a version from floppy when there is a version suitable for ST.

Best regars zChris

[DoG]

...When i look at EmuTOS download i see versions 192, 256 and 512. And from what i have gathered they are suitable for different branches of atari. For Atari ST it is the 192 thats most suitable?...

Easiest to explain is that in Mega/Standard ST(f,m) they have a TOS that is only 192Kb large. STe and Mega STe uses 256Kb TOS ROM. TT and Falcon uses 512 Kb. I can't remember what STacy uses but I think it is 192Kb ROMs.

The memory location for TOS is only 192Kb and you want to use 256Kb ROMs you have to load that in another memory location to get it to even load.

ST and STe both uses normal 68000 processor at 8Mhz but uses different sized ROMs.

EmuTOS is made for that specific sizes for easy uses. To burn on ROMs and put in different computers (even Amiga). However the 192Kb is obvious lacking some part due to it's size. Some parts is not needed since the target machine don't have the supported hardware to use the code anyway.

So the handling of ALT-ram/TT-Ram does not exist in early TOS (ie 192Kb ROMs) and the 64/128Mb RAM on TF536 is put there.