Yet another computer museum - The Epson QX-10

The QX-10 came in several versions, with regional differences. The technical documentation mentions three regions, each having two versions:
U.S.A QX-10 Europe QX-10 Japan QC-10

HASCI version

ASCII version

Standard version

MultiFonts version

Standard version

Kanji version

128 kByte Video RAM 32 kByte Video RAM 32 kByte Video RAM 32 kByte Video RAM
256 kByte Main RAM 64 kByte Main RAM 64 kByte Main RAM 192 kByte Main RAM 32 kByte Main RAM 192 kByte Main RAM

The standard keyboard in the USA seems to be HASCII and in Europe some variations of ASCII.

Each region has its own version of the display character generator, so the extra-ASCII part (128-255) are different.

Upgrading to the maximum is easy, so lot of machines have more RAM.

Disk geometry

The standard disk geometry for the QX-10 is 16 sectors of 256 bytes per cylinder, 40 cylinders (tracks), double sided. Directory is on track 4, side 0.

The TPM-II system disks are different, having 10 512-byte sectors on track 2 and up. There is also a format of 512-byte sectors for all but Track 0, side 0.

The QX+ format introduced with the MML CP/M Plus, uses 5 sectors of 1024 bytes each, resulting in 400 kByte (minus the directory space). This format is not usable for system disks.

Operating systems

Moved to the disk library

DIP switches

In October 2014, Terry Stewart posted details on the DIP-switches in This table is his work, combined with information from Appendix G from the QX10 Operation Manual:

Switch Up (on) Down (off)
Switch 1 Allows the computer to be run from a terminal (at least in Zapple) The computer can only be run by the internal console
Switch 2 Normal mode If TPM-11 (the OS for Valdocs) is booted, then Zapple (a monitor program) will sign on first. Users can then boot to TPM-11 with B command
Switches 3 and 4. As yet unknown. Leave in Up (on) position.
Switch 5 Normal mode Used to test the battery backup (using the Diagnosis program?)
Switch 6 to 8 set according to the amount of RAM in the machine (The switches are read by the Diagnosis program, before it checks the RAM banks).
Switch 6 32 kByte video RAM 256 kByte video RAM
Switch 7 not usednormal position
Switch 8 192kByte main RAM 256 kByte main RAM

Rom dumps

Latest update: 2014-10-17