A8CAS - software for reading/writing Atari 8-bit cassettes
Support for Turbo systems
A8CAS contains preliminary support for tape turbo systems.
There exist several Turbo systems for Atari cassette recorders, mostly originating from Central Europe. A turbo system speeds up communication between an Atari computer and its recorder, allowing programs to load faster and to take less space on tape.
A turbo system typically consists of a piece of electronic circuitry that has to be installed inside an Atari tape recorder, and some software to support the hardware (typically on a cartridge). The circuitry allows to read and write data on a tape in a different way, incorporating Pulse Width Modulation, as opposed to the standard mechanism of Frequency Shift Keying. The circuitry can be switched on and off; depending on the turbo system, it is done either manually by a switch on the recorder's case, or automatically by the turbo software.
Most turbo systems are similar in that they use Pulse Width Modulation to encode/decode data, but they differ in:
- methods of controlling the turbo circuitry (some allow the circuitry to be switched on/off by software, while others incorporate a manual switch on the tape recorder's case);
- formats of files (each system uses its own file format)
Supported turbo systems
Support for turbo systems in A8CAS is currently limited to reading tapes from sound files; saving and conversion to CAS is not supported.
The Atari800 patch allows to select a turbo system of choice; several options are available:
- None - turbo system deactivated
- Manual - allows to switch turbo on/off by user, like in some "Turbo 2000" systems (untested with actual tapes)
- AST (XC12) - Atari Super Turbo from Poland
- Blizzard - Blizzard Turbo
Something to try
Typical view during loading of AST tapes
Here is a ROM image of a utility cartridge for AST, and a tape image of a program in the AST format. Try loading it in the patched Atari800:
- Run the emulator.
- Turn SIO patch off, and set Tape Management→Turbo type to AST (XC12).
- Load the cartridge image to the emulator; when asked to choose the cartridge type, select Phoenix.
- Reset the emulator with BASIC turned off (hold OPTION when resetting). The cartridge will start.
- In the cartridge's menu press 1. The AST loader will be loaded.
- Now load the AST tape image to Atari800.
- Press Space and loading will start. When the name of the program being loaded appears, press Space again.
Check out other AST images as well.