ACSI2STM allows you to use SD cards as Atari ST ACSI hard drives. This manual will explain how to setup and use a SD card.
ACSI2STM was successfully tested on the following hardware:
- Atari 520 STF, TOS 1.04
- Atari 1040 STE, TOS 1.62
- Atari 1040 STE, TOS 2.06
- Atari 1040 STE, EmuTOS (no driver needed)
- Atari TT030
- Plug the ACSI2STM module to the Atari ST's hard disk port.
- Insert a SD card in the first SD slot.
- Plug the power cable to the ACSI2STM.
- Turn on the ST and press Shift+S repeatedly during boot to start the ACSI2STM setup tool.
- Select the ACSI2STM device containing the SD card to format (press '0' for the first SD card).
- Press Q for quick setup.
- Press Y to confirm formating. This may take a few minutes.
- Press Esc twice to exit the menu and reboot the ST.
- The SD card will show up as C: on the desktop.
- The SD card should be compatible with most modern computers.
See a2setup.md for more details on the setup tool.
If you have a bootable hard disk image, the following sections will describe how to use it.
- Use a SD card formatted for PC (FAT32/ExFAT).
- Create a folder named acsi2stm at the root of the SD card.
- Copy your image inside that folder.
- Rename your image hd0.img.
- Don't forget to properly unmount/eject your SD card before removing it from your computer.
- Insert the SD card in the ACSI2STM unit.
- Turn everything on.
- Enjoy.
The file format is the same used by the Hatari emulator. You can test your image in Hatari: go to the menu, click Hard disks, then click Browse on the first line (ACSI HD 0) then reboot the emulated ST. You can even use the image directly on the SD card by opening hd0.img from within Hatari !
When working with disk images, the SD card can be of any size, as long as it uses a standard filesystem (FAT, FAT32 or ExFAT). The ST only sees the content of the hd0.img file.
Note: You can also mount *.st floppy images ! Rename them to hd0.img and the integrated driver will read them easily. This trick is limited to ordinary non-bootable data disks.
If you wish to make your image read-only (for example, to test untrusted software), simply tick the "Read-only" box in the file properties of your image file.
Using a raw SD card is a bit faster than copying the image file.
To transfer images to the disk, you can use Raspberry Pi Imager:
- Open Raspberry Pi Imager.
- Click Choose Os under Operating System.
- Select Use custom in the list.
- Select the image file you wish to transfer.
- Under Storage, click Choose storage.
- Select the SD card you want to write to.
- Click Write to start writing. Existing data on the SD card will be erased. Click Yes to confirm.
- The SD card can now be used on the ST.
If you have a SD card formatted for the Atari (or any other weird format), the Raspberry Pi Imager can revert it back to the standard format so you can use it again on your PC (or any other device).
- Open Raspberry Pi Imager.
- Click Choose Os under Operating System.
- Select Erase in the list.
- Under Storage, click Choose storage.
- Select the SD card you want to write to.
- Click Write to start writing. Existing data on the SD card will be erased. Click Yes to confirm.
- The SD card is now formatted to the standard format.
You can also use the ACSI2STM setup tool to reformat the SD card for a PC.
See a2setup.md for more details on the setup tool.
There is a very good tutorial on Jookie's home page.
Hint: To access files from within Hatari, use the GEMDOS drive feature.
The integrated driver is incompatible with strict mode, so the only way to use it in strict mode is to install it directly onto a disk image.
To do this, the image must be already compatible with the integrated driver and the first partition must start after sector 8.
Boot into the ACSI2STM setup tool (Shift+S on boot), select your device, press P to enter the partitioning tool, then press I to install the driver onto the SD card.
If you cannot boot the ACSI2STM setup tool (it is unavailable in strict mode),
you can transfer A2SETUP.TOS by other means and run it from GEM.
See a2setup.md for more details on the setup tool.
If your ACSI2STM unit comes with a battery, it can keep the time. The integrated driver will set the time automatically.
To set the clock, enter the ACSI2STM setup tool.
See a2setup.md for more details on the setup tool.
ACSI2STM offers extra features that can be dynamically turned on or off with the BOOT1 jumper near the reset button. Since these features aren't 100% SCSI compliant, you can turn them off to have a strict implementation of the SCSI standard.
If BOOT1 is in the 0 position, extra features will be enabled. If BOOT1 is in position 1, extra features will be disabled.
The following features are disabled in strict mode:
- Dummy boot sector if no SD card is present: displays a "No SD card" message on boot if no SD card is inserted.
- Integrated driver.
- Test pattern checking.
- Remote payload execution: Ability to upload and run STM32 code from the Atari ST. This feature is not used.
To check the version of a recent unit, simply plug the ACSI2STM unit to the ACSI port and boot with no SD card or floppy disk. A message will be displayed, indicating the firmware version along with other information.
WARNING: See hardware.md if you wish to upgrade a 1.x or 2.x unit to 3.x, you may need to make changes.
There are many hard disk drivers for the Atari ST out there. All of them come with their pros and cons.
Here is the list of the free drivers I'm aware of, in no particular order:
Just plug the ACSI2STM, insert a non-bootable FAT12/FAT16 MS-DOS partitioned/formatted SD card and boot your Atari.
Pros:
- Officially supported by ACSI2STM. Tested before each release.
- Open source.
- No installation, driver is built-in.
- Reads ST floppy disk images easily (as C:).
Cons:
- Does not support TOS extended partitions.
- No support for BigDOS.
Free (not open source) driver that works well and is very stable.
Pros:
- Officially supported by ACSI2STM. Tested before each release.
- Good set of tools.
- Supports SD card hot swapping (the new SD card must have the same number of partitions).
Cons:
- Incompatible with BigDOS.
- Eats up memory like crazy if you leave cache enabled (disable cache, ACSI2STM is nearly as fast as memcpy).
- Not open source.
Pros:
- Supports MS-DOS partition tables.
- Compatible with BigDOS.
Cons:
- Supports only ACSI id 0.
- Not 100% ACSI standard compliant, does funky stuff on boot (re-enables A1 mid-command).
Pros:
- Fully supporting the SCSI command set.
- Supports more than 1 LUN per drive.
- Very high quality set of tools.
- Supports MS-DOS partition tables.
- Compatible with BigDOS.
Cons:
- The free version is very limited in functionality.
- Does not support ACSI2STM officially (later versions should work).
- Not open source.
The antique driver provided by Atari. While it should work, nobody seem to use it anymore.
Pros:
- Authentic, "pure" Atari experience.
- None, really.
Cons:
- Unsupported by ACSI2STM. Meaning it is never tested, your mileage may vary.
- Incompatible with BigDOS.
- Supports only Atari partition tables.
- Not open source.
The STM32 blue pill has 2 jumpers. You can access to different operation modes just by switching these jumpers to different places.
WARNING: Do not attempt any other combination than what is explained here. You might damage your product.
Normal mode, full featured. ACSI id 0 to 4
_______________________________
| _ |
| [==] o /\ | | -|--
| [==] o / \| | -|--
| \ /| | -|--
| (o) \/ |_| -|--
|_______________________________|
ACSI id 1 to 5, full featured
_______________________________
| _ |
| o o o /\ | | -|--
| [==] o / \| | -|--
| \ /| | -|||| <- Jumper here
| (o) \/ |_| -||||
|_______________________________|
ACSI id 2 to 6, full featured
_______________________________
| _ |
| o o o /\ | | -|--
| [==] o / \| | -|||| <- Jumper here
| \ /| | -||||
| (o) \/ |_| -|--
|_______________________________|
ACSI id 3 to 7, full featured
_______________________________
| _ |
| o o o /\ | | -|||| <- Jumper here
| [==] o / \| | -||||
| \ /| | -|--
| (o) \/ |_| -|--
|_______________________________|
Strict mode, ACSI id 0 to 4
_______________________________
| _ |
| [==] o /\ | | -|--
| o [==] / \| | -|--
| \ /| | -|--
| (o) \/ |_| -|--
|_______________________________|
Strict mode, ACSI id 1 to 5
_______________________________
| _ |
| o o o /\ | | -|--
| o [==] / \| | -|--
| \ /| | -|||| <- Jumper here
| (o) \/ |_| -||||
|_______________________________|
The ACSI id selection jumper on the right works the same as in full featured mode
Firmware programming mode
_______________________________
| _ |
| o [==] /\ | | -|--
| [==] o / \| | -|--
| \ /| | -|--
| (o) \/ |_| -|--
|_______________________________|