RUN .RUN files from CP/M

The usual way to run a .RUN file is to use the SDX ROM. eg:


RUN is a CP/M program which can run almost all .RUN files directly from CP/M, regardless of whether you have an FDX or SDX, or any SDX ROM.

To use, from CP/M, just type :-


It can load any .RUN file that fits within 0x4000 to 0xd000 in memory.

It initialises a few system variables, which is enough for most programs. But there are a few that really need MTX BASIC to have been running and other system variables to have been initialised. Such programs won't work. At time of writing, I am struggling to think of an example.

RUN can be used on a real FDX, a real SDX, in MEMU or on REMEMOTECH.


RUN can be downloaded from

Copying of this program is encouraged, as it is fully public domain. Even the source code is included in the package. It was created on the authors time and equipment. Caveat Emptor.

The author of RUN and this documentation is Andy Key (email

{{{ Andy