[A86] Re: Trying to keep the list (sort of) alive...
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[A86] Re: Trying to keep the list (sort of) alive...
On Sun, 8 Dec 2002 17:19:53 -0500 Ricky Cobb <arcadesdude@intercom.net>
writes:
> rabidcow@juno.com> there must be some sort of check for that. (I
> think it's the check if port $06 is zero)
>
> What about the off checksum?
Ah, I forgot about that. Looks like it checks port 6 for zero, if it is,
it checks that checksum, and if that doesn't match it calls _initialize
to reset the calc:
(on key has been pressed -> 0bfc, rom ver 1.2)
0bfc db06 in a,(#06) ;ram bank page
0bfe b7 or a
0bff caed0c jp z,#0ced
0ced 3e56 ld a,#56 ;power??
0cef d304 out (#04),a
0cf1 3e41 ld a,#41 ;ram page 1
0cf3 d306 out (#06),a
0cf5 97 sub a
0cf6 d303 out (#03),a
0cf8 fd21e5c3 ld iy,#c3e5
0cfc 2ad8c1 ld hl,(#c1d8) ;_onCheckSum
0cff 115aa5 ld de,#a55a
0d02 cd0701 call #0107 ;cp hl,de
0d05 ca630d jp z,#0d63
0d08 3e0a ld a,#0a
0d0a 3208c0 ld (#c008),a
0d0d cdfb0d call #0dfb ;checksum ram page 2
0d10 ed5bd8c1 ld de,(#c1d8) ;_onCheckSum
0d14 cd0701 call #0107 ;cp hl,de
0d17 200a jr nz,#0d23 ;_initialize
0d19 cd1e0e call #0e1e
0d1c fdcb08a6 res 4,(iy+#08)
0d20 c3720c jp #0c72
So it's both :)
-josh
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