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ACSI2STM understanding or in my case Lack of

Posted: 23 Feb 2026 09:29
by Vipersan
Once I had the Atari STe I was gifted fully working it was time to think about storage.
It would appear Ultra Satan would be the preferred method...but having an endless pit of money I chose the less expensive ACSI2STM route..
This came in a printed case with a 32gb sd card.
Not sure why 32gb as only 1gb was used.
popping this sd card in my PC showed 3 partitions but only one of them was recognised C: but at least this proved it was possible to write to the SD ..and the STe would recognise it...but only C:
What is in those other 2 partitions I wonder ?

I did make a 1gb image of the 3 partitions and cloned a second SD card 1GB ...
This worked exactly the same way in both PC and STe

Now I was curious as to how to create a 'drive' from scratch using a blank/raw SD card.
After much reading and even less understanding I figured this _has_ to be done on the Atari and requires a driver be on the SD card C: drive
I found 3 options only one of which is free.
ICD Pro
https://temlib.org/AtariForumWiki/ind...
PPera Driver
https://atari.8bitchip.info/pphdr.php
HDDriver
https://www.hddriver.net/en/
So obviously I opted for the free option.
It didn't work until after some more digging I discovered that there is an unpopulated jumper on the ACSI2STM pcb labeled strict ..
I retrofitted that jumper and linked it.
Now ICDpro worked..but is legacy and running it divided up my 1gb SD card into drives from C: to P:
Only 5 of these are accessible to the ACSI2STM ....via GemDesktop...and non of them via PC.
My assumption for now is that the free legacy option is a throwback to the days when a physical drive would probably be in the region of 40 mb in size.
I clearly have much yet to learn about this process.
I would have purchased the PPera driver and utils from P Putnik ..but he doesn't accept Paypal.
He only accepts payment using WISE..
I've never even heard of it..but when I looked into setting up an account..the process involved submitting photo ID such as the first page of a passport.
..at which point my invasive radar kicked in..
So unless I can find someone who already uses WISE..I wont be trying this driver pack.
The learning process goes on..but this is where I'm at at this point.
Happy to hear from any member on this rather confusing subject.
cheers
VS

Re: ACSI2STM understanding or in my case Lack of

Posted: 23 Feb 2026 09:59
by rubber_jonnie
Whilst HDDriver is the more expensive option, it is the most flexible IMHO. It is also still under development and is updated regularly.

Using the older drivers like ICD won't allow you to simply put the SD card into a PC and copy software directly to it, the partitions are just not visible on a PC. ICD is a good driver but very old.

Now I know when I bought PPera's driver you had to specify if you wanted ACSI or IDE, and I don't know if it's still the same situation now as I bought it a long time ago, but it does also allow for direct use in a PC for file transfers.

Thing is I now use HDDriver exclusively since it will work with any drive including CD drives, ACSI, SCSI and IDE plus you can pop it in your PC and see whats there too.

A 32GB SD card was probably used simply because it's the easiest to get hold of these days and is quite inexpensive.

Re: ACSI2STM understanding or in my case Lack of

Posted: 23 Feb 2026 10:06
by alexh
You could consider EMUTOS as a replacement TOS ROM. The HDD driver in EmuTOS supports FAT16 which means the SD cards will be readable in EmuTOS and on a PC. I *believe* each partition/drive can be 2GiB. (32GiB card = 16 * 2GiB drives C-R)

https://github.com/emutos/emutos/blob/m ... /fat16.txt

I'm not familiar with it's compatibility with games/demos but I believe people use it instead of TOS1.62 (or 2.06)

https://github.com/emutos/emutos/blob/m ... atible.txt

Re: ACSI2STM understanding or in my case Lack of

Posted: 23 Feb 2026 10:18
by Vipersan
alexh wrote: 23 Feb 2026 10:06 You could consider EMUTOS as a replacement TOS ROM. The HDD driver in EmuTOS supports FAT16 which means the SD cards will be readable in EmuTOS and on a PC. I *believe* each partition/drive can be 2GiB. (32GiB card = 16 * 2GiB drives C-R)

https://github.com/emutos/emutos/blob/m ... /fat16.txt

I'm not familiar with it's compatibility with games/demos but I believe people use it instead of TOS1.62 (or 2.06)

https://github.com/emutos/emutos/blob/m ... atible.txt
Thanks guys for your quick replies..
As to TOS version..
I do have the option to switch as I bought a small pcb kit and chip from EXXOS.
so already fitted.
currently TOS1.62 (or 2.06) ..but how easy would it be to substitute a different version ..say EMUTOS instead of one of the TOS versions ?

Re: ACSI2STM understanding or in my case Lack of

Posted: 23 Feb 2026 10:18
by rubber_jonnie
alexh wrote: 23 Feb 2026 10:06 You could consider EMUTOS as a replacement TOS ROM. The HDD driver in EmuTOS supports FAT16 which means the SD cards will be readable in EmuTOS and on a PC. I *believe* each partition/drive can be 2GiB. (32GiB card = 16 * 2GiB drives C-R)

https://github.com/emutos/emutos/blob/m ... /fat16.txt

I'm not familiar with it's compatibility with games/demos but I believe people use it instead of TOS1.62 (or 2.06)

https://github.com/emutos/emutos/blob/m ... atible.txt
Yes, good point and worth considering.

Re: ACSI2STM understanding or in my case Lack of

Posted: 23 Feb 2026 12:09
by Vipersan
Ok..The idea of running EMUTOS on my STe intrigued me..
I found this thread on Exxos.
viewtopic.php?t=3709
There was a version of emutos in a .prg form which I grabbed and wrote to a 720k floppy.
Of course it didn't run with either 1.62 or 2.06
just the bombs when it completed.
I assume this is because it resides in fast ram which I dont have ?
am I correct in this assumption ?
Also looked on Exxos shop hoping to find a pre-programmed plcc chip with emutos on it..but drew a blank.
what am I missing here ..and how do I run EMUTos on my 4mb STe..
keep in mind I am but a Newb to Atari ..
lol

Re: ACSI2STM understanding or in my case Lack of

Posted: 23 Feb 2026 12:18
by alexh

Re: ACSI2STM understanding or in my case Lack of

Posted: 23 Feb 2026 12:38
by Vipersan
Thanks for the link..
Grabbed emutos 1.4 512k images..
gonna have to sort out 20 good floppies..
Thats a lot of images lol

:D

Re: ACSI2STM understanding or in my case Lack of

Posted: 23 Feb 2026 12:57
by Steve
Well firstly I'd point out: https://github.com/retro16/acsi2stm

The Github has extensive documentation which will probably help...

And secondly I want to highlight the Gemdrive mode which allows you to dedicated 1x SD card entirely as a regular, fat16/32/exfat formatted (pc compatible) drive, so you can easily swap data between Atari and PC.

There is a section inside the Gemdrive documentations called "Mixing GemDrive and ACSI" which explains how to use it in conjunction with popular hard disk drivers.

For instance:
Mixing GemDrive and the PP driver (ACSID07)

To mix GemDrive with the PP driver, proceed like this:

Make sure ACSI2STM is configured to start at ACSI id 0.
Insert the card with the PP driver in the first slot.
Insert any other SD card in the extra slots.

The GemDrive driver will load after the PP driver. GemDrive will use L: and above as drive letters.
For me, GemDrive is the 'killer feature' of the ACSI2SD and would be the entire reason I'd buy one.

Re: ACSI2STM understanding or in my case Lack of

Posted: 23 Feb 2026 13:53
by Vipersan
Im even more confused now..
The .img files 512k are obviously not floppy images.
Im guessing they are actually rom images ...tailored for specific languages ?
now I'm wondering ..if these _are_ rom images why they aren't .bin extensions ..and what sorcery is needed to write them to a chip ?
and if this is true ? dont they need to be split Hi Lo..
guess I'm back to reading and learning (hopefully)