edski@mot.UUCP (Ed Skinner) (01/16/85)
When TurboPascal (the compiler, or a created .COM file) begins, it takes
over the breakpoint vector. If you want to "debug" a TurboPascal program,
such as one containing in-line machine code or "external" assembler routines,
you are out of luck: Any breakpoint gets handled by Turbo, not by Debug.
To prevent TurboPascal from snarfing up this vector, modify cs:be2 thru
cs:be4 to hex 90 90 90. (This replaces a "call" instruction with three NOPs.)
Note that reaction to ^C will be "different" (?) and that this patch
should not be used except for debugging purposes. Production code should not
include this patch.
Also, I am told that the September 1984 issue of PC Tech Journal contains
a patch to disable the initial "ClrScr" which occurs when a Turbo program is
started. I think the patch is in a letter to the magazine.
Anyone know a patch to prevent keyboard buffer purging? I.e., to allow
type-ahead? Folks at Borland didn't have one for this.