[A86] Re: user link routine?


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[A86] Re: user link routine?





This flag tells the os to call _alt_slink_exec ($d37c) if the checksum is
set correctly after the first byte (the device id) is recieved during a
silent link (this will always be in the middle of a call to _getkey).  a
and c contain this first byte, and a should contain the same value on
return.  Interrupts are *disabled* during this call and rom page 9 is
loaded.

On return, the value in a is stored to the device id slot in _HEADER and
the remaining 3 bytes from the header are read, then the silent link
routine is chosen based on the second byte, which isn't read until after
this has returned.

Other than to tell the calculator that it can talk to things that it
thinks it shouldn't (or the other way around), the only way to use this
seems to be to drop out of the silent link routine with:
        pop af ; return addr in slink code
        ei
        pop af ;_IOFLAG before slink
        pop af ;_SNDRECSTATE before slink -> has been set to 7
        pop af ;_IOERRSTATE before slink
        ret ; to $28f0
at the end of your code, but I don't know how well this works across
different rom versions.  (or at all, since I haven't tested it ;)

-josh


On Sat, 09 Feb 2002 20:50:37 -0500 Ricky Cobb <arcadesdude@operamail.com>
writes:
> 
> While browing the includes I came across:
> 
> exceptionflg equ $23
> alt_link equ 4 ; enable user link routine
> 
> What is this and how do I use it?
> 
> 
> Ricky Cobb
> http://tiparadise.any.za.net/
> arcadesdude@operamail.com
> [IM]
> icq 41440378
> msn arcadesdude
> y!  arcadesdude
> aim arcadesdude
> 
> 
> 
> 
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