I have two main units and two keyboards.
type computer
country Japan
year 1981?
os CP/M 2.2, Microsoft Basic
cpu Intel 8085A
speed 2.0 MHz
ram 64 KB
rom 2 KB
disk 2 x 8″ floppy
graphic 12″ green text 80 x 24
colors mono
sound beeper
ports 3 x serial RS232
The Panasonic JD-850M — A Rare Japanese CP/M Business Computer
The Panasonic JD-850M is a large, professional CP/M business computer produced by Matsushita Electric (Panasonic) in approximately 1981 — a machine from the era when CP/M ruled business computing and 8-inch floppy disks were the standard for serious professional systems. Using an Intel 8085A processor at 2 MHz with 64 KB of RAM, two 8-inch floppy disk drives, and a 12-inch green phosphor CRT display in an 80×24 character text mode, the JD-850M is a substantial desktop workstation that reflects the professional computing standards of the early 1980s Japanese business market.
CP/M — The Business Standard
The JD-850M ran CP/M 2.2 — Digital Research’s Control Program/Monitor, which was the dominant operating system for serious business computing from the late 1970s until MS-DOS and the IBM PC displaced it in the mid-1980s. CP/M gave the JD-850M access to a substantial library of professional business software including WordStar word processor, dBASE database management, SuperCalc spreadsheet, and numerous accounting and vertical market applications. For Japanese businesses of the early 1980s, a CP/M machine like the JD-850M provided a credible, internationally compatible computing platform.
8-inch Floppy Disks
The JD-850M’s two 8-inch floppy disk drives reflect its early 1981 vintage — at the time, 8-inch disks were the professional standard for business computing, capable of storing more data than the 5.25-inch format that would later become universal. The 8-inch format originated with IBM’s floppy disk development in the late 1960s and became standard in CP/M systems before the smaller 5.25-inch format displaced it through the early 1980s. Machines with 8-inch drives today are genuinely rare, making the JD-850M a historically distinctive piece.
Intel 8085A — CP/M’s Processor
The Intel 8085A processor was a refined version of the 8080 — the processor that had launched the personal computing era with the Altair 8800 in 1975. The 8085A added improved interrupt handling and reduced chip count compared to the 8080, making it a practical choice for business computer designs of the late 1970s and early 1980s. Running at 2 MHz, the 8085A provided adequate performance for the text-based business software of the CP/M era, and its 64 KB address space was standard for CP/M systems of the time.
Rarity
The Panasonic JD-850M is an exceptionally rare machine — large Japanese CP/M business computers from this era survive in very small numbers outside Japan, and even within Japan they are uncommon. The Computer Museum Ata’s collection of two main units with two keyboards represents an unusually complete holding of a genuinely scarce piece of early 1980s Japanese business computing history.