Ferguson Big Board - Specifications

Specifications

Big Board I

• Z80 CPU at 2.5 MHz.
• 64 KB dynamic RAM in 32 4116's or equivalent.
• An ASCII keyboard interface.
• A TTL / composite video CRT interface allowing a display of 24 lines by 80 characters.
• A SS/SD floppy disk interface allowing addition of up to four 8" Shugart Associates SA800 compatible 8" floppy disk drives.
• Two (optional) RS-232 serial ports.
• A parallel Centronics compatible printer port.
• An optional real time clock.
• Board dimensions 8.5" (215mm) by 13.75" (349.3mm). (Compare to SA-800 disk drive: 9.5" x 14.5".)

Big Board II

• Z80 CPU at 4 MHz.
• 64 KB dynamic RAM in 8 4164's or equivalent.
• SASI/SCSI hard disk interface, also usable as a general purpose I/O or for control of other SCSI devices.
• An ASCII keyboard interface.
• A TTL / composite video CRT interface allowing a display of 24 lines by 80 characters.
• A DS/DD floppy disk interface allowing addition of up to four 8" or 5.25" floppy disk drives.
• Two RS-232 serial ports via a Z80 SIO.
• A parallel Centronics compatible printer port via a Z80 PIO.
• An optional real time clock.
• Board dimensions 8.875" (225.4mm) x 14.5" (368.3mm)
• 6 ROM/EPROM sockets, including ability to program EPROMs in place.