2 Apr
2006
2 Apr
'06
4:52 p.m.
Chuck Guzis wrote:
Although I've written several CP/M CBIOSes,
I've never had to write one on
a system that used the Trap vector (0066h) for something essential.
Just curious--has anyone had to deal with servicing the Trap interrupt in
CP/M? How does one keep CP/M from clobbering the vector, since it's in the
FCB2 area?
Chuck, I have no answer for you, but it reminds me of a point I've
always wondered about. The CP/M service call to 0005 takes three bytes
-- why didn't they move it three bytes forward so that the one byte "RST
1" call could have been used instead?