[A86] Re: Trying to keep the list (sort of) alive...
[Prev][Next][Index][Thread]
[A86] Re: Trying to keep the list (sort of) alive...
rabidcow@juno.com> there must be some sort of check for that. (I think it's the check if
rabidcow@juno.com> port $06 is zero)
What about the off checksum?
;----some code someone wrote long ago-----
;part of it was copied from the rom
;$C1D8 is the value on all 86 rom versions
;there are instability issues if you use
;ram page 1 for data (from $8000 on
;since it checks this area when it is turned
;back on for 'corruption' if it turned off
;correctly) if you turn off the calc
;in the prog and use memory in $8000 onward
;
setupchecksum: ;this is from the rom
ld a,$42 ;all rom version have similar code
out (6),a ;to set the checksum on _off
push ix
ld ix,$8000
ld bc,$3fff
ld hl,$0008
ld d,h
offchecksumloop:
ld e,(ix+0)
inc ix
add hl,de
dec bc
ld a,c
or b
jr nz,offchecksumloop
ld e,d
ex de,hl
sbc hl,de
pop ix
ld ($c1d8),hl ;place checksum
-------------------------------------------------------------------------------------
Ricky Cobb III
arcadesdude@intercom.net
Google Answers Researcher
http://answers.google.com/
When you're searching for information, Google Answers.
---------------------------------------------------
My Personal Sites:
http://geocaching.port5.com/
http://tip.ti-programmers.com/
[IM]
msn arcadesdude@hotmail.com
aim arcadesdude
y! arcadesdude
icq 41440378
References: