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#### Pravetz 8D

The emulation is the same as the Oric Atmos. (I don't know if there are any hardware
differences compared to an original Oric Atmos, if there are please tell me and I will
implement them).

Disk:
The disk drive interface has a boot-rom which loads the DOS from the disc
in the drive.

The driver supports 2 versions of the disc interface:
- "low dos 8d" has a 256 byte boot rom and supports DOS v1.0 to v1.30 ("Apple 2" on dipswitch)
- "high dos 8d" has a 512 byte boot rom and supports DOS v2.10 and higher. ("Apple 2 v2" on dipswitch)

If you are using the standard prav8d driver you will need to type:
CALL #320
to start the boot procedure.
If you are using prav8dd (with the "BOBY" rom), then the disc is booted
automatically.
The Pravetz 8D uses Apple 2 compatible disk drives only and these
are supported by the driver.

Here is a brief listing of DOS commands provided by George:

options:
f - FileName (1-30 signs)
d - drive (one or two)
v - volume
a - beginning address
e - end address
l - record length
r - record number
b - number of byte in the record

filetypes:
B - Basic program
C - Bynary file
T - Text file
M - Text file, created with Make command ( batch file:) )

commands:
DIR [1] [2] - not comment
INIT [,Vv] [,Dd] - formatting Disk (in first or second Disk Drive)
DOS [f] [,Dd], [,Vv] - writing Dos on the disk without formatting It. File f automatically starts after booting
MAP [1] [2] - show chart of the disk.
SAVE f [,A,a] [,Ee] [,Vv] [,Dd] - Saves file on the disk. If missing parameter of the addresses A,E -
saving Basic file in Memory
LOAD f [,Aa] [,Dd] [,Vv] - loads file in memory
MERGE - adding program in Basic to already exists in Memory
- -only for files B or C types. Loads file in Memory and start It. (RUN and BRUN together in Apple ][)
DELETE f [,Dd] [,Vv] - deleting file f
RENAME f1, f2 [,Vv] [,Dd] - renaming last name of the file f1 with f2
* f [,Dd] [,Vv] - lock/unlock file
MAXFILES m - allowing up to m open files
VERIFY f [,Dd] [,Vv] - checks surface integrity of file
EXIT - leaving Dos
OPEN f [,Vv] [,Dd] - open file for read/write
CLOSE [f] - closing f. If there's no f pointed - closes all open files
READ f [,Bb] - points that will be reading of the file with command INPUT
WRITE f [,Bb] - writes in Text file
APPEND f [,Vv] [,Dd] - adding information in Text file. Always there's WRITE after It
POSITION f [,Rr] - allow writing or reading in Text file from r position

in Program mode using of the commands is:
10LPRINT CHR$(2); "MAXFILES 5"
e.g.

To load a program called "MONITOR" type:
LOAD MONITOR
often you will see a load address (it is the first number with # prefix).
Now type CALL #<number> to execute the program.

History and Trivia:
The Pravetz 8D is a Bulgarian clone of the Oric Atmos.
It was produced between 1985 and 1989: Pravetz is both the name of the firm and the name of
the city where the firm is located. The "D" in the name stands for "Domashen" ('home' in
Bulgarian) while the "8" stands for (you've never guess!) '8 bits'.

There was a whole family of Pravetz computer which included the following models:
Pravetz 82, 8M, 8A, 8E, 8C, 8D (8 bits)
Pravetz 16, 16A, 286 (16 bits, PC clones)
Most of 8 bits machines were Apple II compatibles, "8D" being the exception. The "8D" model was
issued in 1985 and cost 420 lev - if you think that the average salary by that time was about
180-200 lev, you can see that it was pretty expensive.
The "82" model was the trade name of a machine called "IMKO-2" and was released in 1981. The "IMKO-2"
was the upgraded version of the "IMKO", designed in 1979 and used for robot control.
The main differences from the Oric Atmos were obviously the keyboard and the floppy interface.
The Pravetz 8D can display both Cyrillic and Latin alphabets - the one currently in use is selected
by the key labelled "C/L" which takes place of the "FUNCT" key present on the Atmos. Other features
of the keyboard are the "ESC" and "CTRL" keys, labeled respectively "OSV" and "MK".
During Pravetz' glory days none of Oric's disk interfaces were imported in Bulgaria, thus the magazine
"Computer for you" organized a competition to develop a disk interface which was compatible with
the most widespread disk drive currently used, namely the Apple II's disk drive.
The competition was won in 1989 by Borislav "Boby" Zahariev, student at MEI University of Sofia.
The first version of the disk interface used top 16Kb of RAM to store the DOS, which prevented
users from loading larger programs. Later Boris developed an upgrade of his interface which
used in conjunction with a new version of the DOS allowed programs to use the whole memory. He provided
also a new version of BIOS which detected the presence of the interface and automatically booted
the DOS from the disk.

Thanks to:
Joro Dramchev, Ventzislav Alexandrov and Todor Arnaudov for Pravetz information,
Fabrice Frances for Oric information.

Generated on Wed Jul 16 01:11:08 2003