SAPI R

Also called JPR-12R.Designed by Ing. Eduard Smutný.It was manufactured from 1980 (according to documentation 1980/11) by Tesla Strašnice. The computer was inspired by or was successor to PDP 11/40. Hardware is based on 74181 (PDP-11 ISA).Operating systems running on the computer: FOBOS 3,DIAMS,OSPD.

Parts of this topic may be machine translated.

Circuit boards

Each 360x360mm board has 5 edge connectors spaced 2.5mm each with 2x18 contacts, on which the PDP-11 UNIBUS bus is connected. There are minor differences in connection between individual cards, e.g. supply voltages. The ALU and BUS cards form a defacto unit with many internal connections beyond the scope of UNIBUS, their connection is solved on a printed circuit board and additional coiled connections. The front panel (PNL) is connected using wires.

System JPR 12R

(The number indicates the fixed position in the backplane)

Common Bus Boards

According to the documentation, the data bus is quite compatible between the cards, the power supply voltage (GND, 5V, +18V, -18V) is again not unified.

Cabinets

Compatibility with PDP/11

Probably a copied PDP-11/05 (the KD11B processor corresponds to the wiring up to the details of the JPR 12 R). The interesting thing is that the processor is clocked using an R-C oscillator, the crystal was apparently a "bourgeois survival" ;-).

Periphery

References