Kenner 2 page 4 July 1977 Co Filmer, translated to english Hans Otten, 2021

A parallel ASCII keyboard is a nice addition to the KIM-1.

Connect to the PIA A of the KIM-1 on the Application connector.

Some keyboards may require a -12 V power supply.

The address 1700 now shows the ASCII keyboard code of (the last) key pressed. The high bit (PB7) is the strobe signal, the other 7 bits the ASCII code.

A program should poll the strobe bit, if activated wait for the strobe bit to be deactivated, and then read the key and return.
Testing for keypressed such as a break test means checking the strobe bit, if activated stop processing, etc..

Code fragments by Hans Otten

PAD * $1700 ; BREAKKEY IN BIT 7
   ; SUBROUTINE GET CHARACTER
   ;
GETCH BIT PAD ; PROCEDURE GETCHARACTER ( CHAR ) 
 BPL GETCH ;   WAIT FOR STROBE
GWAIT BIT PAD ;   WAIT FOR END OF STROBE 
 BMI GWAIT ;
 LDA PAD ;   GET CHARACTER
 RTS  ; END GETCHARACTER
   ;
   ; example of break test
   ;
SYN BIT PAD ;   REPEAT
 BPL GOON ;     WHILE NOT keypressed
 JMP MONRET ;      
GOON continue processing