Re: Input/output on the Apple ][

[pausch@saaf.se (Paul Schlyter)]

In article <1122169481.326838.256140@g14g2000cwa.googlegroups.com>,
 <sam124@operamail.com> wrote:
 
>> If you are talking about the built-in text display, or the
>> keyborad, the firmware to control the operation is
>> already provided in ROM.
> 
> That's exactly what I was thinking.  What I need to know is, what
> subroutines or soft-switches do it and what are there locations?
 
 
Input from built-in keyboard:
INP     LDA  $C000
        BPL  INP
        STA  $C010
(character typed is in A)
 
 
Poll built-in keyboard to see if char is available:
        LDA  $C000
("minus" flag set if character available, clear if not)
 
 
Output to screen:
(character to output should be in A)
        JSR  $FDED.
 
 
Input from keyboard, echo to screen:
INP     LDA  $C000
        BPL  INP
        STA  $C010
        JSR  $FDED.
(character typed+echoed is in A)
 
 
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