A modern hard disk device for Atari ST/MegaST/STE/MegaSTE
The ACSI2STM is an open-source hard drive emulator designed for Atari ST computers, enabling the use of SD cards as storage devices. Powered by an STM32 microcontroller, it bridges the Atari’s ACSI port with modern SD cards, providing a cost-effective, reliable, and versatile solution for expanding storage on vintage Atari systems.
Key Features:
- Broad Compatibility: Supports Atari models such as 520 STF, 1040 STE, Mega ST, and Mega STE.
- Operating Modes:
- GemDrive Mode: Offers seamless access to SD cards formatted with FAT16, FAT32, or ExFAT. This mode eliminates the need for additional drivers, making it easy to transfer files between your Atari and modern PCs.
- ACSI Mode: Emulates traditional ACSI hard drives and supports multiple partitions. This mode requires Atari-compatible hard disk drivers, offering enhanced compatibility with legacy software.
- Real-Time Clock (RTC): Includes UltraSatan-compatible RTC functionality, enabling accurate timekeeping on the Atari. A 3V lithium battery (CR2032 not included) is required for this feature.
- Firmware Upgradeable: The ACSI2STM firmware can be updated directly from the Atari, ensuring compatibility with future enhancements and bug fixes.
Kit Contents
When purchasing the ACSI2STM kit, you’ll receive:
- A PCB with all components soldered and tested, including a DB-19 connector built with pins for the Atari ACSI port.
- A IDC-20 connector to expand the ACSI port to Satan Disk and other devices. Not soldered.
- Pre-installed latest stable firmware.
The user will have to provide:
- A USB-C cable to power the ACSI2STM.
- A SD, SDHC, or SDXC card to store files. They must be formatted in FAT16, FAT32, or ExFAT for GemDrive mode or with Atari-compatible hard disk drivers for ACSI mode as described in the documentation.
- A functional Atari ST/MegaST/STE/MegaSTE/TT computer with an ACSI port.
Installation
The ACSI2STM is already pre-assembled and embeds the latest firmware, making it ready for use out of the box. The only steps required are to prepare an SD card and connect to your Atari system:
3. SD Card Preparation
- For GemDrive Mode: Format the SD card with FAT16, FAT32, or ExFAT to allow the Atari to access files directly without additional drivers.
- For ACSI Mode: Create disk images or partitions compatible with Atari’s hard disk drivers for legacy software.
4. Operation
- Insert the prepared SD cards into the slots.
- Connect the ACSI2STM to the Atari’s ACSI port.
- Power the ACSI2STM using a USB-C cable (not included).
- Power on the system. The Atari should detect the SD card as a hard drive, ready for file storage and retrieval.
This product is intended for users familiar with basic embedded systems and vintage computer hardware. While we offer support for hardware setup and firmware installation, the firmware is provided as-is. It is actively and continuously developed, and we encourage users to contribute by reporting bugs and suggesting features on the GitHub repository.
Frequently Asked Questions
What is the difference between GEMDRIVE and ACSI modes?
- GEMDRIVE Mode: Allows easy file transfers between Atari and modern PCs using FAT16, FAT32, or ExFAT formatted SD cards. No additional drivers are needed.
- ACSI Mode: Emulates a traditional ACSI hard drive, supporting legacy Atari software with custom partitions. Requires Atari hard disk drivers like HDDRIVER or ICD Pro.
Choose GEMDRIVE for convenience and modern workflows, and ACSI for full compatibility with vintage software.
Why do I need a USB-C cable?
The ACSI2STM requires a USB-C cable to power the device because it cannot draw enough power from the Atari’s ACSI port. The USB-C cable should be connected to a USB power source, such as a computer, USB charger, SidecarTridge Multi-device, or a USB power bank.
Can I use the ACSI2STM with SidecarTridge Multi-device?
Yes, the ACSI2STM is compatible with the SidecarTridge Multi-device, allowing you to connect multiple devices to your Atari simultaneously. The SidecarTridge Multi-device can power the ACSI2STM using its USB-C port, simplifying the setup and reducing cable clutter.
My Atari STE suffer from the Bad-DMA issue. Can I use the ACSI2STM?
The latest firmware of the ACSI2STM includes a workaround for the Bad-DMA issue on Atari STE computers called PIO mode. You must enable this mode by following the instructions in the documentation. PIO mode may reduce the performance of the ACSI2STM by a factor of 10, but it ensures compatibility with Atari STE computers affected by the Bad-DMA issue.
Can I upgrade the firmware of the ACSI2STM from the Atari itself?
Yes, the latest firmware of the ACSI2STM can be updated directly from the Atari using the firmware update utility. This feature ensures that you can benefit from future enhancements and bug fixes without needing additional hardware or tools.
What is the difference between the GEMDRIVE in the ACSI2STM and the SidecarTridge Multi-device?
Both drink from the sources of the Hatari emulator. The GEMDRIVE in the ACSI2STM uses the specific messaging system of the ACSI device to communicate with the Atari, but in the SidecarTridge Multi-device, the GEMDRIVE uses the messaging system implemented over the cartridge port. Both try to bypass the limitations of the Atari ST operating system to access small disk drives.
Why don’t you ship to some European countries?
I’ve made the difficult decision to discontinue shipping to Austria, Bulgaria, Cyprus, France, Greece, Latvia, Lithuania, Luxembourg, Portugal, Romania, Slovakia, Spain and Sweden. This decision was not made lightly and is primarily due to the specific and significant costs associated with recycling packaging and electronics in these countries. Unfortunately, these costs are disproportionately high relative to the demand I’ve experienced, making it unsustainable for me to offer the products in these markets while adhering strictly to the legal requirements.
However, you can still find this and other products in various marketplaces like eBay, Tindie and others with a simple search.
More information
- Documentation: You can read the guides in our documentation section.
- Documentation: Detailed guides and tutorials are available on the project’s GitHub repository, covering hardware setup, firmware installation, and SD card preparation.
- License: The ACSI2STM is an open-source project released under the GNU License. You can access the source code and contribute to the project on the GitHub repository.
