John Bell Engineering SBC’s

John Bell Engineering was a small firm producing microprocessor many boards between 1980 and 1990.
The early boards were 6502 and Z80 SBC’s, later boards were for the Apple II, and the last ones for the IBM PC bus.

I present here, what I have found, of three boards in the spirit of http://retro.6502.nl. Any additional information, like software, is appreciated!

82-300 Three IC’s SBC 6502, 6532 2716
80-153 SBC 6522, 6502

82-300 (circuit drawn by Mike K8LH)

One of the smallest 6502 based computers possible with the technology of the 1980ties!

Any additional information, like software, is appreciated!

Three IC’s SBS 6502 CPU, 6532 RIOT, EPROM  2532 or 2716, expansion connector, RC oscillator, one transistor decoder


80-153 6502 micro

Five IC’s SBS 6502, 6522 VIA,  2716 EPROM, 2x 2114 SRAM, 74LS10 decoder

There was a revision, connecting phi2 to pin 11 of the ‘LS10, “to improve memory response”

(Clock modification with crystal,  Don Sawyer)

There was a revision, connecting phi2 to pin 11 of the ‘LS10, “to improve memory response”, so the wire is soldered!

There was a revision, connecting phi2 to pin 11 of the ‘LS10, “to improve memory response”