Re: New Input Routine

[Rubywand <rubywand@swbell.net>]

Jon Bettencourt writes ...
> 
> I need a new input routine that does this:
> 
> ClosedApple-A produces a 2.
> ClosedApple-S produces an @.
> ClosedApple-Z produces a CTRL-2 (null).
> 
> Those are to cheat my way out of having a malfunctioning 2 key.
>
> ClosedApple-D produces CHR$(4);
> ClosedApple-P produces PRINT
 ....
> 
> Those are just for shortcut-taking.
 ....

     You can write and BLOAD a routine to intercept KB inputs and change them--
something like 'if it's this, change it to this'.  But, needing to BLOAD the
code makes it useless as a general purpose fix. To work with all of your
software, the change needs to be implemented in the '$F8' monitor ROM area.

     You do not want to mess up established routine entry points; so, adding
features to the monitor usually involves substituting a PROM which can include
code for JUMPing to some other PROM, say, on a Slot card, to do the new stuff.

     Or, you may be able to scrap some monitor feature and substitute your new
code. On Apple II's which include cassette tape I/O, the tape R/W functions
might be scrapped. (You don't have to permanently lose old ROM access. The old
ROM can ramain in place and you can use a switch to select the ROM or PROM.)

     Replacing the "2" key seems like an easier fix for a bad key switch than
modifying the monitor ROM.

     For the other special features, you could change the ROM code or you could
BLOAD the new key routines for use with specific applications and change the
INPUT vector at $0038, $0039 to point to your new key handler.




Rubywand