This japanese computer seems quite powerful. The main board is located into the main case, under the monitor.
Inside this main case there are 6 expansion slots which is quite enough ! Thus a lot of expansion boards were available (disk, printers, 8088, Z80 boards, etc).
An interesting feature is that there's a little trap-door on the keyboard which reveals some cool control switches : a power switch, a text mode switch (80 / 40 columns), a reset button and volume control knob. Quite useful !
Please consider donating your old computer / videogame system to Old-Computers.com or one of our partners from anywhere in the world (Europe, America, Asia, etc.).
Memory came in two sizes, 16k and 64k. Our School computer lab was full of these but only 2 had 64k in 1985/86 then replaced with IBM xt clones
Sunday 6th June 2021
Michael Schipp (Australia)
@Rusty, I would be interested in those cards. Do you still have the schematics?
Thursday 1st April 2021
Carlos Camacho (United States)
I designed a number of add-on cards for this computer in my teenage years - two floppy disk controllers, hard disk interface with networking, multifunction card with rtc, two ay-3-8910 psg chips and a spo256 speech chip along with two atari joystick ports and a z80 card to run cp/m. I still have those boards but not the computer. It was a very well made piece of hardware and very reliable - too expensive for me to buy at the time.
Thursday 26th May 2016
MB-6890 / Basic Master Level 3
BUILT IN LANGUAGE
Hitachi Level-3 Basic Version 1.0 (Copyright Microsoft)
QWERTY full-stroke keyboard, separated numeric keypad, 5 function keys
24k (Basic Interpreter)
80 x 28 / 40 x 25
80 x 100 / 160 x 100 / 160 x 200 / 320 x 200 / 640 x 200
6 expansion slots, RS232c, Tape-recorder
Tape-recorder, printer interface board, light-pen, Chinese character ROM board, 8088 CPU board, Disk Interface board, Z80 CPU board, RAM expansion boards