website/content/museum/mostek-md.md

title, categories, types, origins, years, cpus, params

title	categories	types	origins	years	cpus	params
Mostek MD	Computers	Professional Computer	U.S.A.	1979	Z80	name company company_name specs tabs photos hardware oc_id source MD /companies/mostek Mostek label value NAME MD label value MANUFACTURER Mostek label value TYPE Professional Computer label value ORIGIN U.S.A. label value YEAR 1979 label value BUILT IN LANGUAGE Monitor in ROM label value KEYBOARD Depending of the video terminal used label value CPU Z80 label value SPEED 4 Mhz label value CO-PROCESSOR None label value RAM 8 KB expandable to 64 KB label value TEXT MODES 80 chars x 25 lines label value SOUND No sound label value SIZE / WEIGHT 54 (W) x 60 (H) x 44 (D) cm. / Heavy! label value I/O PORTS 2 x serial, 2 x A/D-D/A, 1 x Parallel, video terminal label value BUILT IN MEDIA 2 x 8 label value OS CP/M label value POWER SUPPLY 3 x built-in power supply units (+24V for FDD / + 5V / +12 -12V) label value PERIPHERALS All STD Bus cards label value PRICE Unknown photos hardware title subtitle text image COMPLETE SYSTEM MD system with a Volker-Craig video terminal null title subtitle text image TERMINAL CLOSE-UP null title subtitle text image BOTTOM RACK #1 The bottom rack holds two 8" floppy drives null title subtitle text image BOTTOM RACK #2 The two impressive floppy drives with their own 24V power supply unit. null title subtitle text image TOP RACK #1 From left to right: - CPU board\ - 32 KB RAM and Parallel port board\ - Dual serial port board\ - Floppy drives controller board null title subtitle text image TOP RACK #2 null title subtitle text image BACK SIDE #1 **(1)** +12V / -12V power supply unit\ **(2)** +5V second power supply unit\ **(3)** Dual 64 lines bus. Bottom bus is used for addresses and data lines, top bus is used for I/O. Main boards use the dual bus, some others **(5)** only use the bottom one.\ **(4)** I/O cables. They are normally fixed to the back panel. null title subtitle text image BACK SIDE #2 **(1)** Z80 bus I/O connector\ **(2)** Analogue / digital converter connector\ **(3)** Composite video connectors. Video signal comes from the main CPU board.\ **(4)** Parallel connector\ **(5)** 2 x Serial connectors\ **(6)** Video terminal connector null title subtitle text image WIRED BUSES Notice that the system didn't use backplane but handy wired buses. null title subtitle text image CPU BOARD This board holds all the necessary chips allowing it to be used as a stand alone unit. **(1)** Mostek Z80 processor\ **(2)** Step by step switch\ **(3)** Reset switch\ **(4)** 16 KB RAM memory (8 x 4116 chips)\ **(5)** 4 KB Monitor ROMs (4 x 2708)\ **(6)** Z80 CTC - Counter Timer Circuit\ **(7)** 2 x Z80 PIO - Parallel Input Output Controllers null title subtitle text image ANALOG CARD Analogue to Digital and Digital to Digital conversion card. null 819 url date https://web.archive.org/web/20221205022457/http://www.old-computers.com/museum/computer.asp?c=819 2022-12-05

The Mostek MD (from Micro Design) marked the entry of Mostek Company in the computer business.
It was a development system, aimed at promoting the family of Mostek boards, and built around several boards based on the 64 pin SDT bus.

The hearth of the system was the CPU board holding a Z80 (Mostek) processor, 10 KB of ROM and 8 KB of RAM. A large range of additional cards could be then added: dual Serial port, 32 KB RAM, Analogue/digital converter, 32-bit parallel port, and so on.

Using an ASCII video terminal, a basic one-board system allowed machine code programs to be assembled, debugged and run thanks to the built-in ROM monitor.

A complete system - like the one pictured - could manage two 8" floppy disc drives and run CP/M Operating System. However, these systems were mainly used for managing external devices in laboratories, universities and industry.

Special thanks to John Jenkins