Difference between revisions of "84PCE:Syscalls:021D7C"
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(Created page with "SignExtendDE_broken 021D7C - SignExtendDE_broken == Synopsis == '''Hypothesized Official Name:''' Si...") |
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Here is what this routine calls, if you can find a particular use for it, go for it. | Here is what this routine calls, if you can find a particular use for it, go for it. | ||
| − | <nowiki> push af | + | <nowiki> push af |
xor a | xor a | ||
ld (0D02AD7h), de | ld (0D02AD7h), de | ||
| Line 24: | Line 24: | ||
ld de, (0D02AD7h) | ld de, (0D02AD7h) | ||
pop af | pop af | ||
| − | ret</nowiki> | + | ret </nowiki> |
Revision as of 18:39, 4 May 2015
Synopsis
Hypothesized Official Name: SignExtendDE_broken
Syscall Address: 021D7Ch
This is supposed to extend the signed 16-bit DE value to be 24-bit signed.
However, due to what looks like a copy-paste error by TI, this routine is pretty much useless.
It looks like they tried to use code from SignExtendBC, and forgot to change a byte.
Here is what this routine calls, if you can find a particular use for it, go for it.
push af xor a ld (0D02AD7h), de bit 7, b ; This should be d, not b jr z, _+ dec a _+: ld (0D02AD9h), a ld de, (0D02AD7h) pop af ret
