[A83] Re: ports


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[A83] Re: ports




> ----------------------------------------
> From: Michael Vincent <hookman@worldnet.att.net>
>
> Port 9 This is the status port for the link assist. Read this port and AND
> 38h. If nonzero flag, then the link assist has a byte in its buffer or is in
> the process of receving a byte.

So this is what happens in the _getkey routine? It checks for activity with port 9 and if there is activity it calls a receive-byte routine. Should be, but Dan told me ones that bit 4 indicates wether there's a byte ready to be received or not. So this would mean you have to AND with 10h (or just BIT 4,a) and not with 38h. So now I was wondering what the TIOS does before calling _recAByte.

Also, when making a program that should work on both the TI83+ and TI83+SE, one should implement some code like this or is there a better way?

linkReceive:
   bcall(_getBaseVer)
   dec   a
   jr    nz,above112
   ld    a,b
   cp    13
   jr    c,TI83Plus
above112:
   bcall(_nzIf83Plus)
   jr    nz,TI83Plus
TI83PlusSE:
   in    a,(9)
   and   38h
   jr    chkReceive
TI83Plus:
   in    a,(0)
   and   03h
   cp    03h
chkReceive:
   ret   z
   ..call MirageOS receive routine..

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