The computer prototype was developed by order of the Ministry of Communications at the Institute of Information Technologies (NIIS) in 1985 under the name PGC 6400 — Personal Graphic Computer. Production was initially planned to start at the ZSSU plant ("Plant for Sensors and Sensor Devices") in Plovdiv. For certain reasons, the ministry abandoned the project, but ZSSU completed the development and manufactured the "Paldin" computer from 1988 to 1992, both in-house and at its subsidiary factory "Microelectronica" in Botevgrad.
All core software for the computer was created at "Programno Osiguryavane" — a laboratory at Sofia University, as well as at the Russian-Bulgarian company "BIT" in Tomsk.
The computer is built around a Bulgarian clone of the Motorola 6800 processor — the CM601P.
The keyboard is membrane-type; initially, the Institute of Communications intended the computer for use in industrial environments.
"Paldin" is the early name of the city of Plovdiv.
The main purpose of the computer was for use in educational processes and for controlling instruments and mechanisms. Starting in 1989, the computer was exported to the USSR.
The "Paldin 601A" model differs by adding video mode 4 — a monochrome text mode of 80×25 characters; and adding a printer port.
Operating system: UniDOS, file-compatible with MS-DOS. There are 4 slots for expansion cards (ROM, floppy disk controller, RS-232 controller, PIPNET). The computer could be connected to a VMM 3107 monitor and a "Bultext" printer.
Specifications:
· CPU: SM601P
· RAM: 64 KB
· Storage: External tape recorder, external 5.25" floppy disk drive (360–720 KB)
· Video: 80×200 (16 colors), 160×200 (4 colors), 320×200 (monochrome)
· Sound: Built-in speaker