Heathkit DEC H-11 Digital Computer System (Zenith Data Systems)

Heathkit DEC H-11 digital computer system. This H-11 uses the same microprocessor, memory, I/O, and operating system as the DEC LSI-11, and runs all the software designed for the DEC PDP-11/03.. The CPU is the KD11-HA half size card, which includes the extended arithmetic (floating point) processor. The computer is full-up, including 32K words of 16 bit memory, the floppy interface, two serial I/O cards, and the parallel I/O card. There is one empty backplane slot.

The H-27 floppy disk subsystem features two 256K 8" single side, single density drives. The drives are DEC RX01 compatible, and, unlike the DEC products of the day, are able to format the floppies,.

Hardware: WH27 Factory Wired Dual 256K Floppy Disk Drive System, WH11A Factory Wired H11A Digital Computer, w/ KD11-HA (LSI-11/2) Half Size CPU, Front Panel Line Time Clock Switch, H-11-6 KEV11 Extended Arithmetic Chip, H11-27 Floppy Disk Interface Card, (2) WHA-11-16 Factory Wired 16K Memory Expansion Modules, WH-11-5 Factory Wired Serial I/O Interface Card, H11-5 Serial I/O Interface Card, H-11-2 Parallel I/O Interface Card, WH-11-51 Serial Interface Adapter Cable (EIA), Spare H27 8" Disk Drive

Software: HT-11 Operating System, HT-11 BASIC, HT-11-1 FORTRAN, (30) Blank 8 inch floppy discs in (3) plastic library cases

(Pictures and specifications courtesy of Michael Frieders.)







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