Download Z8E User`s Manual (C) 1984 - Chicago Classic Computing

Z8E - Z80 DEBUG MONITOR
Rick Surwilo
Z8E will pass the row address in the B REGISTER and the
column address in the C REGISTER. Row numbers range
from 0 to 23 while column numbers range from 0 to 79.
Your job is to translate these two number into a cursor
postion on the screen of your CRT.
Save all registers including BC.
skeleton as a guide:
ASEG
.PHASE
XXXX
PUSH
PUSH
PUSH
BC
DE
HL
Use
the
following
;From
Z8E.SYM
YOURS:
CURSOR ADDRESSING CODE HERE
POP
POP
POP
RET
HL
DE
BC
END
Use ZBE/s output routine TTYO as described above (or
your own routine) to output the characters in your
cursor addressing sequence. Obtain the absolute address
of TTYO from the file Z8E.SYM. Code the call to the
subroutine using the absolute address in hexadecimal.
For instance, if Z8E.SYM contains the entry:
2FE2
TTYO
then code your call statements as:
CALL
2FE2H
ZBE imposes only one restriction on the code you write.
In order to guarantee that your
cated into high memory by Z8E do
constants into register pairs;
loads.
For example, do not use
ment:
LD
HL,1234H
Rather, code it like this:
LD
LD
routine can be relonot load any 16 bit
instead do two 8 bit
the following state-
H, 12H
L,34H
10