Background:
In the 80's Bulgaria was the biggest computer manufacturer in this part of the world.
Also - first in the world
- for the proportion of manufactured computers per person
in the country.
History:
IMKO 1 and IMKO 2 were the first models (circa 1980 and 1982); in 1983 IMKO 2 was renamed to Pravetz 82,
because Todor Zhivkov (Bulgarian government and communist party leader at this time) was from Pravetz -
a small town, near to Bulgaria's capital city, Sofia.
IMKO 1,2 and Pravetz 82 were almost identical clones of the Apple ][. Then the Pravetz factory built the Pravetz 8M (which was unique at the time)
because of its 2 onboard CPU's - 6502 & Z80 (used as a built-in CP/M module). It also had 64 KB of RAM onboard
(16 KB as built-in RAM expansion in slot 0).
In the following years they also built: Pravetz 8E, 8A, 8C and 8S - clones of Apple //e.
. 8E didn't have the Cyrillic font, unlike all other models, it had lowercase and
capital Latin letters, like original Apple's.
. 8A have 2 additional basic commands, 8 bit code-pages, mini-assembler, allowed
the use of hex codes in BASIC and some additional subroutines
in the built-in ROM. Unfortunately, some important entry points of the monitor (ROM) program were changed, so it was not 100%
compatible with older Apple (and Pravetz) models. This is easily corrected by changing some code (usually JMP in binary
programs or CALL, POKE, PEEK
in BASIC programs), but not very simple, especially for ordinary users.
. 8C was a stripped down version of 8A (so like the Apple //c) but its size wasn't smaller, like //c. It was without an auxiliary slot
of 8A (Apple //e), instead it had 64 KB RAM built-in to its address space. It also had a CM630 CPU (6502 analogue), which had
some bugs when used with the CP/M module. 8C also had a built-in RGB module for color monitor (slot 7) and of course the improved
80 column card of the Apple //e, like 8E and 8A.
. 8S was a further improved version of 8C with a possibility to change DRAM chips to 1 MB of memory.
(It was possible to do this with Pravetz 8C and the expansion card of 8A: in order to have 1060 MB of memory.)
There were also other Pravetz models:
. 8D was a version of the Oric/Atmos - "D" means "Dom" - "Home" in Bulgarian.
Other models were 16 bit - IBM PC XT and AT clones:
. Pravetz 16, Pravetz 16, Pravetz 16A, Pravetz 16H, Pravetz 16T (with Nec V20 CPU)
. Pravetz 286 (286 CPU), Pravetz 386 (with 386 CPU) and Pravetz 486 - experimental, only a few were manufactured.