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 (circuit drawn by Mike K8LH)
One of the smallest 6502 based computers possible with the technology of the 1980ties!
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!