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Re: ACSI2STM understanding or in my case Lack of
Posted: 26 Feb 2026 16:58
by Vipersan
rubber_jonnie wrote: 26 Feb 2026 16:53
Vipersan wrote: 25 Feb 2026 14:47
You could very well be correct Alex.
...which is why I have created 2 versions..
one of them should work..
That said..I prefer to understand the process than just doing it blind..
OK so I think endianness is the issue here, and I'm struggling to remember when I was writing my own 27C4096's with 2.06 and Emutos that I wrote one and it didn't work, so that was £8 down the drain as it was an OTP IC, after which I bought stock of UV erasable 27C4096's.
Unless you have erasable ROMs, either electrically or UV I would get some before committing the image to ROM. Also if you want to change the version of Emutos later an OTP ROM isn't going to let you do that.
I can't find the backups of the images I actually used, but it may be on my Windows laptop I use in my workshop, I'll have a look, but I really don't remember if they were byteswapped or not.
Can you spare one from your stock jonnie ?
Like I say ..of the files I've created one of them should do the job ..but one time programmable is risky at best ..which is why I need to test with a UV erasable chip ..and of course test my new adapter.
can you help buddy ?
cheers
VS
Re: ACSI2STM understanding or in my case Lack of
Posted: 26 Feb 2026 17:00
by exxos
Vipersan wrote: 26 Feb 2026 16:24
PLCC 27C4096 UV erasable
Didn't see any for sale on Exxos shop or I would have placed an order immediately.
I haven't been following many threads lately, but just happened to see the above comment, if you're referring to the PLCC UV ROM They are in the shop..
https://www.exxosforum.co.uk/atari/store2/#0251
Re: ACSI2STM understanding or in my case Lack of
Posted: 26 Feb 2026 17:12
by Vipersan
exxos wrote: 26 Feb 2026 17:00
Vipersan wrote: 26 Feb 2026 16:24
PLCC 27C4096 UV erasable
Didn't see any for sale on Exxos shop or I would have placed an order immediately.
I haven't been following many threads lately, but just happened to see the above comment, if you're referring to the PLCC UV ROM They are in the shop..
https://www.exxosforum.co.uk/atari/store2/#0251
I did say my eyesight is not good these days..
Thanks for the direct link Exxos..
order for 2 chips placed
:D
..and if you should find the bin files you have already created Jonnie...I'd love to try flashing them to the eproms just ordered from Exxos...with my new GQ-4v4 adapter
Re: ACSI2STM understanding or in my case Lack of
Posted: 26 Feb 2026 17:15
by rubber_jonnie
Vipersan wrote: 26 Feb 2026 16:58
Can you spare one from your stock jonnie ?
Like I say ..of the files I've created one of them should do the job ..but one time programmable is risky at best ..which is why I need to test with a UV erasable chip ..and of course test my new adapter.
can you help buddy ?
cheers
VS
I only have a few on them so can't really spare them unfortunately, but see the post from
@exxos he has them in the store here:
27C4096 UV erasable in store
Please also have a look at the attached zip file, just remove the .txt from the end and unzip and there are a few pre-made images that I built, both byteswapped and normal, there is a TXT file in there describing the various images.
I did just do a quick test and the non-byteswapped images work with Hatari, however I don't know if that's the case with a real machine, I just can't recall as it was a long time ago.
In the case of the TOS2.06 and Emutos images, it's an older version of Emutos but there's no reason why you couldn't edit the file to remove the old version of Emutos and insert the new one instead.
Re: ACSI2STM understanding or in my case Lack of
Posted: 26 Feb 2026 17:19
by Vipersan
rubber_jonnie wrote: 26 Feb 2026 17:15
Vipersan wrote: 26 Feb 2026 16:58
Can you spare one from your stock jonnie ?
Like I say ..of the files I've created one of them should do the job ..but one time programmable is risky at best ..which is why I need to test with a UV erasable chip ..and of course test my new adapter.
can you help buddy ?
cheers
VS
I only have a few on them so can't really spare them unfortunately, but see the post from @exxos he has them in the store here:
27C4096 UV erasable in store
Please also have a look at the attached zip file, just remove the .txt from the end and unzip and there are a few pre-made images that I built, both byteswapped and normal, there is a TXT file in there describing the various images.
I did just do a quick test and the non-byteswapped images work with Hatari, however I don't know if that's the case with a real machine, I just can't recall as it was a long time ago.
In the case of the TOS2.06 and Emutos images, it's an older version of Emutos but there's no reason why you couldn't edit the file to remove the old version of Emutos and insert the new one instead.
Thanks for the files buddy..now I just wait for my Exxos order ...
:lol:
Re: ACSI2STM understanding or in my case Lack of
Posted: 26 Feb 2026 17:53
by rubber_jonnie
Vipersan wrote: 26 Feb 2026 17:19
Thanks for the files buddy..now I just wait for my Exxos order ...
:lol:
No worries.
Re: ACSI2STM understanding or in my case Lack of
Posted: 04 Mar 2026 15:02
by Vipersan
The 2x 27c4096 UV erasable plcc I ordered from Exxos arrived this morning...so set to work flashing the bin file I created earlier ...
And yes it works which is great.
My thanks to everyone for their advice.
I now can switch easily from TOS 206 to EMUTOS 1.4
I'm including the binary file for the 27c4096 for others to use.
After much searching and asking I couldn't find this combo...so had to learn how to do it.
rgds
Re: ACSI2STM understanding or in my case Lack of
Posted: 04 Mar 2026 16:17
by alexh
Can you post the technique. Did you need to byteswap?
Re: ACSI2STM understanding or in my case Lack of
Posted: 04 Mar 2026 17:05
by Vipersan
alexh wrote: 04 Mar 2026 16:17
Can you post the technique. Did you need to byteswap?
Not that much to it Alex..
If your img or Binary starts with 2E 60 then it is NOT byte swapped...if it starts with 60 2E then it is ALREADY byte swapped..
I'll use TLL866 software as an example
Open file with programmer software to check this..
If not already byte swapped ie both 256K images one starting at 000000: ...the second image needs to start at 020000:
So regardless of pre or post byte swap...the 2 images need to be concatenated that is to say joined end to end to create a 512k image from 2 x 256k images...see my earlier post for details (online tools for both operations)
The only criteria at this point is not to concatenate (join) a byte swapped image to a non byte swapped image
If working with a joined 512k image already byte swapped... simply write to chip..
If working with a joined 512k image not byte swapped ..then it must be byte swapped before writing to chip..
Hope this makes sense..
Re: ACSI2STM understanding or in my case Lack of
Posted: 06 Mar 2026 12:38
by Vipersan
For now at least I'm happy with the STe ..and it finally has a permanent home next to my Quad-Flop PC.
All repairs done and the TOS switchable between TOS 2.06 and EMUTOS.
Now this is where my Atari knowledge is severly lacking..
Are there any games or software which will NOT function with either TOS.
Not unlike the incompatibilies that exist between Amiga 500 and 1200 kind of thing.
Also where I might find and download mod files ..that will run from floppy preferably.
I have some games ..but no music/graphical programs to try ?
rgds
VS