This page was last modified 16:55, 13 August 2021 by Mars2000you. Based on work by Gdx and Rderooy and others.



Initializes the Memory Disk and deletes all existing files on this device.

On MSX2 and higher, a message indicates the number of bytes allocated to the Memory Disk.

Note: on the MSX1 Toshiba machines, ON ERROR GOTO does not work properly when the Memory Disk is available.




<Size> is normally optional and available only on MSX2 and higher machines.

  • To get a working Memory Disk, the value needs to be higher than 1022 except with MSX-BASIC 2.1, for which the value needs to be higher than 6654
  • To get a Memory Disk with the maximum size, just enter CALL MEMINI without the size parameter nor the parentheses.
  • To disable the Memory Disk, you can use CALL MEMINI (0).

If you use Delta BASIC, please note that

  • You need to specify the size and only values between 1023 and 16384 will be accepted
  • Delta BASIC is incompatible with the Memory Disk under MSX-BASIC 1.0, 2.1 and the European 2.2 version made by FRS
  • The following Delta BASIC instructions are incompatible with a Memory Disk previously created with CALL MEMINI: CHAIN, COMMON(), RESTORESCREEN, STORESCREEN, WINDOW.



Allocated bytes

The minimum memory space that can be reserved for the Memory Disk on MSX2 and higher is 256 bytes.

When the size must not be specified and is omitted, the computer will reserve by default the maximum memory space that it can allow to the Memory Disk without reducing the memory space allocated to MSX-BASIC. This maximum is generally higher with version 2.1 of MSX-BASIC, because this version uses also the 128 or 256kB memory mapper for the Memory Disk (see table below).

The using of Delta BASIC strongly reduces the maximum number of allocated bytes for the Memory Disk.

MSX-BASIC version Maximum allocated bytes + Delta BASIC Machines
1.0 31232 Incompatible Toshiba HX-20 (all versions), HX-21 (only the Japanese version), HX-22 (only the Japanese version), HX-31, HX-32
2.0, 2.2 (*)
3.0, 3.1, 3.2
4.0, 4.1
32000 15616 Most MSX2 machines, all MSX2+ and MSX Turbo R machines
2.1 222976 Incompatible Sakhr AX-500 (**)
2.1 91904 Incompatible AVT CPC-300
Bawareth Perfect MSX2
Daewoo CPC-400 (***), CPC-400S (***)
? Fenner FPC-900 (to be checked)
? Laser MSX2 (to be checked)
Philips HCS 280, NMS 8245, NMS 8250, NMS 8255, NMS 8260, NMS 8280, VG-8235 (****)
Phonola NMS 8245, NMS 8280
Sakhr AX-350, AX-350II, AX-370
Sanyo MPC-2300, MPC-2500FD
Talent DPC-300, TPC-310
Wandy CPC-300
Yamaha YIS-503IIIR, YIS805-128R2
2.1 26368 Incompatible Philips NMS 8220 (only 64kB RAM)
 ? Talent TPP-311 and TPS-312 (only 64kB RAM; to be checked)

(*) Version 2.2 by Digital Design or Japanese version 2.2 by FRS - Note: the European version 2.2 by FRS is based on 2.1
(**) This machine displays "version 2.0", but it's actually hidden version 2.1
(***) These machines don't display the MSX-BASIC version after boot, the BIOS rom indicates 2.0, but it's actually hidden version 2.1.
(****) This machine has been produced in different versions, the first versions (8235/00, 8235/02, 8235/16 and 8235/19) have MSX-BASIC 2.0, but next versions (8235/20, 8235/22, 8235/29, 8235/36 and 8235/39) have MSX-BASIC 2.1.

Related to



MemoryDisk BASIC