Beta Disk Interface
Beta disc interface is a disk interface for ZX Spectrum computers. It was developed by Technology Research Ltd (UK), in 1985. Beta 128 is a version for ZX Spectrum 128 machines. Beta disc interfaces were distributed with TR-DOS operating system in ROM, also attributed to Technology Research Ltd. Latest firmware version is 5.03 (1986). The interface is based on WD1793 chip.
The interface handles single and double sided, 40 and 80 track double density floppy disks, up to 4 drives.
Clones
This interface was popular for its simplicity, and Beta 128 disc interface was cloned all around USSR. First known USSR clones were ones produced by НПВО "Вариант" (Leningrad) in 1989.[1] Beta 128 schematics are included in various Russian ZX Spectrum clones.
Some variants of schematics support only 2 drives. Phase correction of drive data signal is made different ways.[2][3]
Operating systems supporting Beta 128 disc interface
References
- ^ Sinclair ZX Spectrum. Beta Disc / TR-DOS. Аппаратные средства. Стандартный интерфейс дисковода. - С.-Петербург, 1994
- ^ Рюмик С. Контроллер дисководов. Канал записи / Радиолюбитель. Ваш компьютер, 1998, NN10-12; 1999, N1
- ^ Рюмик С. Контроллер дисководов. Канал чтения / Радиолюбитель. Ваш компьютер, 1999, N4-8