[A83] Re: rst 20h crap
[Prev][Next][Index][Thread]
[A83] Re: rst 20h crap
EDB0 ldir
C9 ret
the zeros: fill until next rst, probably
>But..., what about the EDB0C90000??
>
> SUCKER
>
>>At 0020h there's a jp to _HLToOP1 (to the real routine, not the equate)
>>Btw, this routine copies 9 bytes, not 8 as you said.
>>
>> >From: "The one and only SUCKER ..." <sucker_pvn@hotmail.com>
>> >Reply-To: assembly-83@lists.ticalc.org
>> >To: assembly-83@lists.ticalc.org
>> >Subject: [A83] rst 20h crap
>> >Date: Tue, 21 Aug 2001 20:41:07 +0000
>> >
>> >
>> >I found out something weird. rst 20h (TI-83-) is the
>> >same as op1=(hl). So far so good. And rst 20h is the
>> >same as call 20h. The next rst is rst 28h, so there
>> >are eight bytes with possible code which is executed
>> >with rst 20h. At 20h there is: EDB0C90000... , which
>> >is ldir/ret. If you follow so far, rst 20h should then
>> >be the same as ldir and the same as op1=(hl).
>> >But this is not!
>> >
>> >for ldir, bc is how many bytes, hl is from where to
>> >copy to the addres in bc, so bc would have to be eight
>> >(like eight bytes with possible code in rst 20h) and
>> >de would point to op1 so that whenever you execute
>> >ldir, everything would be set to that to copy the
>> >following bytes at (hl) to op1.
>> >
>> >But no!!
>> >
>> >What the hell this is about????
>> >If I think this way everything should match (like replacing stuff)
>> >But have I made an error??
>> >
>> >Here a prmg that uses rst 20h:
>> >
>> > ld hl,name
>> > rst 20h
>> > call _chkfindsym
>> > ret nc
>> > jp _getkey
>> >;when the prgm AWELCOME exists, and is not protected
>> >;Done is displayed, otherwise it waits for a key input.
>> >
>> >name: .db 5,"AWELCOME",0
>> >
>> >_________________________________________________________________
>> >Get your FREE download of MSN Explorer at
>>http://explorer.msn.com/intl.asp
>> >
>> >
>> >
>>
>>
>>_________________________________________________________________
>>Get your FREE download of MSN Explorer at http://explorer.msn.com/intl.asp
>>
>>
>>
>
>
>_________________________________________________________________
>Get your FREE download of MSN Explorer at http://explorer.msn.com/intl.asp
>
>
>