PC 88
It was manufactured from 1987 by Tesla Piešťany. The computer was inspired by or was successor to IBM 5150. Hardware is based on i8088.
The circuit solution of the PC-88 computer is on one flat board of dimensions 250X285 mm, on which there are 131 integrated circuits. The flat plate is designed by the method of flat wires (MULTIWIRE) and the board is a six-layer classic flat plate. It contains a memory subsystem RAM with a capacity of 256 K8, of which up to 64 KB can be allocated for video pages and 8 KB of ROM memory, which contains the system firmware - BIOS. In addition, there is a discrete video processor for an RGB monitor, a 5.25" (minifloppy) disk controller for four drives, an 8253 timer, an interrupt system, a printer and keyboard interface with detailed circuits and three local bus connectors for system expansion. This motherboard is enough connect the mini-floppy disk drive, voltage source + 5V / 4A, keyboard and monitor. From a design point of view, the entire system is implemented similarly to the IBM PC / XT.
- 8 / 16-bit 8088 processor
- clock frequency 4MHz
- RAM memory 256 KB (expandable)
- ROM memory 8 KB (BIOS)
- video memory 64 KB with alphanumeric output 80/40 X 25 characters and with graphic 640/320 X 200 points
- 5-level interrupt system
- acoustic programmable (8253) output
- separate 85-element keyboard
- built-in power supply + 5V / 8A; 12V / 1.5A
- built-in 1 (2) minifloppy disk drives with a capacity of 180 (360) KB each
- introduced local bus for expansion (three modules)
- CENTRONICS interface for printer output
The 8 KB BIOS firmware contains routines for diagnostics, video, disk, printer, timer, RS 232 interface of the system from the mini-floppy disk drive. These procedures are created in such a way that even with a qualitatively different circuit architecture, they are as compatible as possible with the IBM BIOS.
References
- https://www.retromania.sk/cs/letopocet-1980-1989/osobni-pocitac-tesla-pc-88 (WebArchive)
- KIŠŠ, Roman a STRÁNSKÝ, Martin. Osobní mikropočítač PC-88. Basic Input Output System. Piešťany: Tesla, 1988.