2K Z80 Monitor Program for Microbyte MZ80A-IO
This program is a custom 2K eprom monitor routine that runs on a Z80 cpu card in the top 2K of memory space. This particular version runs on a Microbyte MZ80A-IO cpu card. It uses several pieces of hardware on other boards in the system. The system console uses the serial port (ports 2,3) on an IMSAI MIO serial/parallel/cassette tape board. Sample serial code is also included that accesses the 2 serial ports on the MZ80A-IO CPU card. A second big section of code is used for booting CPM from a parallel port interfaced SD card disk interface. Details will be revealed on another web page that is currently under construction. This parallel port micro SD card disk is interfaced through a port on the IMSAI MIO card. A 64K ram card with the top 2K disabled is used in the system for RAM.
The MZ80A-IO is a complete single board S100 bus Z80A CPU with 2 serial ports (Z80A-DART)
with switch selected baud rates from 50-19200 baud,
24 bits of parallel I/O (8255), an on board eprom socket for 2708, 2716 or 3732,
2 or 4MHz processor speed jumper, adjustable wait states and full vectored interrupt
capability and 2 Z80A CTC counter timer chips. This board sold for between $280USD
and $349USD in the early 1980's.
The original maufacturer contact information:
Microbyte, 1198 E. Willow St., Signal Hill, CA 90806, (213)595-8571
(from Byte Magazine Feb 1981 page 149)
I have not been able to locate a schematic or user manual
documentation for this board. Please contact me if you any further information.
The hardware setup:
- The Microbyte MZ80A-IO Z80 CPU card.
- Tanner 64K static ram card.
- The IMSAI MIO serial/parallel *2/ cassette interface card.(optional)
- The optional BUSMON card for debugging and blinking lights.(optional)
s100-busmon project