PMD 85 - Variants

Variants

• The PMD 85, first version, produced by Tesla Piešťany (author was Roman Kiss), was originally in a white-coloured case and later in some other colours. It was more of a prototype and is quite rare today.
• The PMD 85, second version, produced by Tesla Bratislava, was known as "the" PMD 85, and sometimes labeled as PMD 85-1. It was made with a dark gray case, and was famous for its keyboards with extremely tough keys. Alphanumeric keys were evaluated at the moment of a key release.
• The PMD 85-2 introduced some improvements in BASIC, some in input routines (for instance, key autorepeat), a much more ergonomic keyboard (but much less mechanically reliable) and also terminal mode. Some of the changes caused it to be not completely backward compatible.
• The PMD 85-2A used 64 Kib chips instead of 16 Kib, leading to less overheating of the memory chips, resulting in more memory available for BASIC, but was otherwise compatible with PMD 85-2.
• The PMD 85-3 added colour TV output. Character encoding included all Czech and Slovak characters, and a Cyrillic version was also produced. System monitor was enlarged to 8 KiB and included routines for communication with PMD 32 floppy disk assembly, a ROM integrity test and also "PMD 85 compatibility mode" by relocation.

The PMD 85-2 was an inspiration for the MAŤO personal computer, also sold as a self-assembly kit. It had different hardware and very limited compatibility with PMD; its BASIC, memory structure and I/O were almost, but not completely the same, but tape format was different. It was intended as a home computer, but never really caught on.

Later, the Didaktik Alfa and Beta were produced as more reliable clones.