MZ-40K was an ancestor of the Sharp MZ computers series. It was a single-board microcomputer in a plastic covered box. Sharp called it "Dr. Microcomputer (MAIKON HAKASE)". It was designed as a consumer electrical appliance and sold as a toy or a training tool for the first microcomputers fans.
The MZ-40K had a built-in speaker and could play music automatically or become an organ, using the monitor keys. Software was included into the 4-bit CPU ROM and users could run several basic applications without any programming skill.
MZ-40K wasn't a marketing success, mainly because it was designed only for beginners without expansions capabilities, while the major competitor, NEC TK-80, offered a full range of software and hardware expansions.
Karl Heinz Mau (sharpmz.org) reports us:
it uses an AC Adaptor 10.5 Volt (AC !!). Not DC, because the clock functions uses the 50 Hz of the power to generate the clocking (seconds by a blinking LED-point, minutes, hours).
The complete computer was sold as a kit! The operating manual contains about
25 pages (of 68) to build the MZ-40K.
There are two options for the MZ-40K which could be bought seperately.
Option 1 is named Sensor. It is a REED or microswitch used to play
self-programmed melodies continuosly or one to 15times. It can be
used too for counting events when the switch is pressed. The number of
events will be displayed with the LEDs.
Option 2 is an organ keyboard kit to play your melodies. It is connected by a 12 wires cable.
There are 7 global and choosable functions of the MZ-40K:
2 Timer ( plays a melody/tone at a specified time )
3 Organ by its keyboard
4 Playing melodies (3 octaves, 127 notes)
5 Telephone costs. To this you have to set the MZ-40K into this mode
by using some keyboard functions. You press RUN at the beginning of your
call and STOP at the end. MZ-40K will show the costs... from 1
german penny up to 15 stepped by 1 penny. May be, this can be used for
other purposes too?
6 Games (like cube or cube games, roulette, car race, hunting deer, etc.)
7 the 6 sensors make several applications possible...
ADR to set the address in RAM to be read/write
READ to read and display at the LEDs the hexadecimal contents of a RAM
WRITE to write the hexadecimal data typed in by the keyboard into the RAM
CLEAR to delete/correct wrong data typed in
RUN execute a program (1 to 7, see above)
STOP to stop the execution
0 - F hex keyboard or to play the musical note shown on the key (e.g. Mi,
Fa, Fa# etc.)
Thanks to Ohishi Nuboaki and his Sharp MZ dedicated website and Karl Heinz Mau for informations and pictures.