00001 *************************
00002 *
00003 * POLCAT.ASM
00004 * MDJ 09-25-90
00005 *
00006 * POLLS THE KEYBOARD FOR
00007 * A KEYSTROKE
00008 *
00009 *************************
00010 *
00011 * U AND S STACKS MUST
00012 * ALREADY BE INITIALIZED
00013 *
00014 * NO ENTRY CONDITIONS
00015 *
00016 * ON RETURN:
00017 *  IF NO KEY PRESSED -
00018 *   CC FLAG Z = 1
00019 *   REGISTER A = 0
00020 *  IF A KEY WAS PRESSED -
00021 *   CC FLAG Z = 0
00022 *   REGISTER A = KEY
00023 *
00024 * ANY ROUTINE CALLING
00025 * THIS MUST PSHS A,CC
00026 * BEFORE CALLING AND
00027 * PULS A,CC ON RETURN
00028 *
00029 *************************
00030 *
00031 RAMROM  EQU     $FFDE   RAM/ROM MODE
00032 ALLRAM  EQU     $FFDF   ALL RAM MODE
00033 XPOLCT  EQU     $A000   ROM POLCAT JUMP ADDRESS
00034         ORG     $3F9B
00035 POLCAT  PSHS    Y,U,DP
00036         STA     RAMROM  SET RAM/ROM MODE
00037         JSR     [XPOLCT] GO TO ROM POLCAT
00038         STA     ALLRAM  SET ALL RAM MODE
00039         PULS    Y,U,DP
00040 ZEND    RTS
00041         END
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
