John,
Yes you are correct, checking and changing himem only if it’s lower would work. But the whole point of this is giving the user the ability to load a CO file through an ASCII transfer because they don’t have another means of loading a CO file (other than cassette). So the likelihood of there being another program loaded is rather slim. Kurt From: M100 [mailto:[email protected]] On Behalf Of John R. Hogerhuis Sent: Monday, May 15, 2017 4:18 PM To: [email protected] Subject: Re: [M100] BASIC CLEAR question On Mon, May 15, 2017 at 3:22 PM, Kurt McCullum <[email protected] <mailto:[email protected]> > wrote: Thanks John, That will solve my problem. I realize that there could already be something in memory, but the loader would really only be for a case where someone has a Model-T without an option ROM or REX who wanted to load TS-DOS. So in theory, there shouldn't be anything up that high in that condition. Obviously a warning would be in order. Kurt What I'm getting at is say a user likes to keep two programs in memory. TS-DOS and something else. The something else you CLEAR memory BELOW where TS-DOS will load at, load to high ram at that spot below where TS-DOS will be. Delete it's .CO file and create a trigger file so you only have one copy in RAM. When TS-DOS loads, if it doesn't check for how low HIMEM is, it will move HIMEM higher, leaving the user's program unprotected. I think the problem would be avoided by only poking HIMEM lower, if necessary. The only other option is that they only load TS-DOS into a system with no resident programs, i.e. TS-DOS always happens first. -- John.
