This collection of files is MP/M 1.1 implemented for the Systems Group
System 2800, an S-100 machine.  This particular unit has two 8" DSDD 
floppy disks, no hard disk, contains two 64k banks of RAM and has four 
serial ports.  It supports three users.

The sources in this collection are designed to be compiled with the
MicroSoft M80 assembler and the MicroSoft L80 linker, which are not
included for reasons of copyright.

Several submit files are included which may help illustrate how all 
this goes together:

ASMPRL   SUB   2k 
ASMSPR   SUB   2k 
LDR201   SUB   2k 
MACPRL   SUB   2k 
MACSPR   SUB   2k 
SG201    SUB   2k 

As I recall (it's been a lot of years) the system first booted to CP/M and
then ran MPMLDR.COM to take it multiuser.  It would run two copies of 
WordStar simultaneously, but lacked enough memory to bring up a
third.  You were down to small utilities on that third terminal.