Date   : Wed, 25 Jul 1984 00:03:00 MDT (Wed)
From   : Richard Conn <RCONN@Simtel20.ARPA>
Subject: Custon OpSys

       In a word, nothing is impossible given the time.  I see two
immediate problems with writing an opsys in BASIC:  (1) you would have
to org the absolute binary to the CCP location or modify the cold boot
routine to load the binary at its execution address and (2) you would
have to restrict the use of the run-time library as much as possible
if you want to store the opsys on the system tracks.

       In the ZCPR3 environ, if you want to have a BASIC application
act as your front-end (shell), then it can be done quite easily with
SHSET.  Just give the command "SHSET MBASIC MYSHELL" and MBASIC
MYSHELL will always be running.  You may be able to use POKE to store
a command for ZCPR3 to run in the command line buffer and then exit
the MBASIC, at which time the command in the buffer wll run and MBASIC
MYSHELL will be reexecuted.  If this is what you want ...

               Rick