PMD 85
PMD 85 was a personal computer produced from 1985 onwards (as the name says) by Tesla Piešťany, later by Tesla Bratislava, in the former country of Czechoslovakia. The reason why this computer was produced was lack of foreign currencies to buy systems from the West. After the fall of socialism production of the PMD85 was stopped - it was not able to compete in price, quality or features with PCs.
Specifications MHB 8080A 2MHz CPU 48 KB RAM 4 KB ROM System monitor Tape utilities TV output 288×256 resolution 4 levels of gray/colours (changeable in 6 pixel wide stripes) tape recorder interface ROM module interface (A ROM module with BASIC was a standard part of computer, there were more ROM modules designed and produced (with Pascal, LOGO etc...))
Version history
PMD 85 was produced in several versions: - PMD 85 first version, produced by Tesla Piešťany, originaly in white colour box, later in some other colour mutations. More like a prototype, quite rare
- PMD 85 second version, produced by Tesla Bratislava - this is known as the PMD 85, sometimes called PMD 85-1, in a dark gray case. It was famous for its keyboards with extremely tough keys.
- PMD 85-2 introduced some improvements in BASIC, some in input routines (key autorepeat), much more ergonomic keyboard (but much less mechanically reliable). Some of the changes caused it to be not completely 100% backward compatibile.
- PMD 85-2A used different hardware, less overheating memory chips, additional 8 KB RAM, more memory for BASIC, but was otherwise compatible with PMD 85-2.
- PMD 85-2B had 64 KB memory modules instead of 16 KB ones
- PMD 85-3 added colour TV output (former versions had colours only with a monitor), and some more hardware changes, including mapping all the address space into RAM (so it could be made almost 100% compatible with previous models by loading their ROM in appropriate places). Character encoding contained all Czech and Slovak characters. There was also a version with cyrillic produced.
They were en mass deployed in schools throught Slovakia, while in Bohemia the same role had been played by IQ 151. PMD 85's were famous for their overheating problems (nicknamed coffe machine). PMD 82-2 was an inspiration for personal computer MAŤO, sold also as a self-assemble kit. It had different hardware and unfortunately had very limited compatibility with PMD (BASIC, memory structure and I/O were almost, but not completely the same, but tape format was different). Intended as home computer, it never really caught on. Later, Didaktik Alfa and Beta were produced as more reliable clones.
External link
DJ Martin Schotek's page
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