LOMEM.200 -- Sept. 25, 1987
  James Yi  73327,1653  Copyright 1987

This file describes how to set LOMEM on Tandy 200 for alternate method of 
storing machine language programs.


LOMEM, as opposed to HIMEM, is the area of ram just below where files are 
stored, and it is normally not accessed by the operating system.
Initially, when Cold start has been performed, the Basic system doesn't set 
aside any area for LOMEM to exist.

Nevertheless, it can be created and binary files can be stored there safely.

The advantage of LOMEM is that using it will save memory, because it eliminates
the need for a backup .CO file, which is loaded at certain address above HIMEM,
thus taking up double the space of its actual length.  It also is convenient if
 you have several ML programs competing for the same space in HIMEM.  By 
relocating each program into LOMEM, they don't have to interfere with each 
other.

Its disadvantage is that files in LOMEM cannot be readily deleted, as you can 
with a .CO file by KILLing it.



To set LOMEM on T200, first create LOMEM.CO by runnig the following BASIC
program.

Chksum = 20,485


10 FORM=65400TO65482:READD:POKEM,D:NEXT:SAVEM"LOMEM",65400,65482,65400:NEW
100 DATA 33,185,255,205,204,17,205,240,84,205,23,9,42,238,244,62,160,131,87,148,71,14,0,105,210,159,255,197,124,146,71,98,205,218
110 DATA 130,193,195,166,255,205,168,130,218,120,255,9,58,98,246,128,50,98,246,124,50,239,244,214,160,50,0,160,195,98,44,76,111,109
120 DATA 101,109,32,115,105,122,101,32,40,120,50,53,54,41,0



Then decide how many bytes in LOMEM you want to reserve and RUNM"LOMEM.CO".

The size of LOMEM will be the number entered*256.

The resulting LOMEM space available starts at 40961, and ends at 40961 + (the
number entered*256)-1.

Relocate ML programs to this area and CALL to run them, or you can write a 
short file manager program.


Saving the LOMEM to cassette is just like you would with a .CO file. But
loading is a bit tricky, as you will get ?OM error if you try to load it the
usual way.

So first type:  X=PEEK(61109):POKE 61109,0

This lowers the HIMEM value.  Then load it in as you would normally. When it's
loaded in, don't forget to restore HIMEM value by  POKE 61109,X.


Feedback about problems or suggestions on improvements are welcomed.