Use Modify to change the two bytes at 0621H
I’m sure you can guess what that does, and if you can’t, you can look it up in the
Nas-Sys manual under ‘how to end a program’. Excuse the digression. Once you have
Zeap in your memory use the Modify command on the following:
|and at||15EB, 1644, 1853, 185B, 1B36, 1B94, 1BFD, 1C0E, 1C17, 1020, 1C2C|
|1082, 1CBF, 1CC8, 1CD2, 1DE2, 1B20, 1E30, 1E40, 1E73, 1EE7, 1FBA|
All the above changes move the screen to the place CP/M expects to find it except
1849, which took rather a while to find ... it’s used to locate the cursor on the
screen, and is the 2’s complement of the number they actually mean...
I’m now working on disk save/get routines from within ZEAP, though where
I’ll put them I don’t know; probably I’ll remove the +/– option adjust. that gives
me the two command letters I require, and a bit of room inside ZEAP. I guess one of
the routines will have to appear at 2000H, so I’ll have to move the start of text to
allow for that. Full marks to the writers of ZEAP for making that bit easy, if
nothing else. By the way, all this surgery upsets the routine that checks that all’s
well within ZEAP, so you’ll get Error 90 every time you do a cold start. The way
around that is to find a unused byte, such as 1FFDH (I hope) and fiddle with it till
ZEAP starts OK.
I’ve also got Nas-Pen (compatible) working (guess what I wrote this on)
under CP/M but I can’t for the life of me remember how I did it. Still, someone else
has done it, and documented it too, so find that and the world is yours.
PiP PiP Chaps.
INPUTting and READing Double Precision Constants (continued)
–– o0o ––