Difference between revisions of "84PCE:Syscalls:021D80"
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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. | ||
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push af | push af | ||
xor a | xor a | ||
Revision as of 17:43, 4 May 2015
Synopsis
Hypothesized Official Name: SignExtendHL_broken
Syscall Address: 021D80h
This is supposed to extend the signed 16-bit HL 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.
SignExtendHL_broken: push af xor a ld (0D02AD7h), hl bit 7, b ; This should be h, not b jr z, _+ dec a _+: ld (0D02AD9h), a ld de, (0D02AD7h) pop af ret
