Routines to light LED display by multiplexing the seven segment LED and checking if a key is pressed.

1030   1EFE             ;
1031   1EFE             ;       SUB TO DETERMINE IF KEY IS 
1032   1EFE             ;       DEPRESSED OR CONDITION OF SSW 
1033   1EFE             ;            KEY NOT DEP OR TTY MODE     A=0
1034   1EFE             ;            KEY DEP OR KB MODE      A NOT ZERO
1035   1EFE             ;
1036   1EFE             ;
1037   1EFE A0 03       AK      LDY   #$03       ;  3 ROWS
1038   1F00 A2 01               LDX   #$01       ; DIGIT 0
1039   1F02             ;
1040   1F02 A9 FF       ONEKEY  LDA   #$FF
1041   1F04 8E 42 17    AK1     STX   SBD        ;  OUTPUT DIGIT
1042   1F07 E8                  INX              ;  GET NEXT DIGIT
1043   1F08 E8                  INX   
1044   1F09 2D 40 17            AND   SAD        ; INPUT SEGMENTS
1045   1F0C 88                  DEY   
1046   1F0D D0 F5               BNE   AK1
1047   1F0F                     .EJECT 
1048   1F0F A0 07               LDY   #$07
1049   1F11 8C 42 17            STY   SBD
1050   1F14             ;
1051   1F14 09 80               ORA   #$80
1052   1F16 49 FF               EOR   #$FF
1053   1F18 60                  RTS  
1054   1F19             ;		
1055   1F19             ;       SUB OUTPUT TO 7-SEGMENT DISPLAY **
1056   1F19             ;
1057   1F19 A0 00       SCAND   LDY   #$00       ; GET DATA SPECIFIED 
1058   1F1B B1 FA               LDA   (POINTL),Y ; BY POINT
1059   1F1D 85 F9               STA   INH        ; SET UP DISPLAY BUFFER
1060   1F1F A9 7F               LDA   #$7F       ; CHANGE SEG
1061   1F21 8D 41 17            STA   PADD       ; TO OUTPUT
1062   1F24             ;		
1063   1F24 A2 09               LDX   #$09       ; INIT DIGIT NUMBER
1064   1F26 A0 03               LDY   #$03       ; OUTPUT 3 BYTES
1065   1F28             ;
1066   1F28 B9 F8 00    SCAND1  LDA   INL,Y      ; GET BYTE
1067   1F2B 4A                  LSR   A          ; GET MSD
1068   1F2C 4A                  LSR   A
1069   1F2D 4A                  LSR   A
1070   1F2E 4A                  LSR   A
1071   1F2F 20 48 1F            JSR   CONVD      ; OUTPUT CHAR
1072   1F32 B9 F8 00            LDA   INL,Y      ; GET BYTE AGAIN
1073   1F35 29 0F               AND   #$0F       ; GET LSD
1074   1F37 20 48 1F            JSR   CONVD      ; OUTPUT CHAR
1075   1F3A 88                  DEY              ; SET UP FOR NEXT BYTE
1076   1F3B D0 EB               BNE   SCAND1
1077   1F3D 8E 42 17            STX   SBD        ; ALL DIGITS OFF
1078   1F40 A9 00               LDA   #$00       ; CHANGE SEGMENT
1079   1F42 8D 41 17            STA   PADD       ; TO INPUTS
1080   1F45 4C FE 1E            JMP   AK         ; GET ANY KEY
1081   1F48             ; 		
1082   1F48             ;       CONVERT AND DISPLAY HEX 
1083   1F48             ;       USED BY SCAND ONLY
1084   1F48             ;
1085   1F48 84 FC       CONVD   STY   TEMP       ; SAVE Y
1086   1F4A A8                  TAY              ; USE CHAR AS INDEX
1087   1F4B B9 E7 1F            LDA   TABLE,Y    ; LOOKUP CONVERSION
1088   1F4E A0 00               LDY   #$00       ; TURN OFF SEGMENTS
1089   1F50 8C 40 17            STY   SAD       
1090   1F53 8E 42 17            STX   SBD        ; OUTPUT DIGIT ENABLE
1091   1F56 8D 40 17            STA   SAD        ; OUT PUT SEGMENTS
1092   1F59             		
1093   1F59 A0 7F               LDY   #$7F       ; DELAY 500 CYCLES APPROX.
1094   1F5B 88          CONVD1  DEY  
1095   1F5C D0 FD               BNE   CONVD1
1096   1F5E             	;
1097   1F5E E8                  INX              ; GET NEXT DIGIT NUM
1098   1F5F E8                  INX              ; ADD 2
1099   1F60 A4 FC               LDY TEMP  ; RESTORE Y
1099   1F60 A4 FC       
1100   1F62 60                  RTS
1101   1F63             ;		
1102   1F63             ;       SUB TO INCREMENT POINT
1103   1F63             ;
1104   1F63 E6 FA       INCPT   INC   POINTL
1105   1F65 D0 02               BNE   INCPT2
1106   1F67 E6 FB               INC   POINTH
1107   1F69 60          INCPT2  RTS
1108   1F6A             ;
1109   1F6A             ;       GET KEY FROM KEY BOARD 
1110   1F6A             ;       RETURN WITH A=KEY VALUE
1111   1F6A             ;       A GT. 15 TEHN ILLEGAL OR NO KEY
1112   1F6A             ;
1113   1F6A             ;
1114   1F6A A2 21       GETKEY  LDX   #$21       ; START AT DIGIT 0 
1115   1F6C A0 01       GETKE5  LDY   #$01       ; GET 1 ROW
1116   1F6E 20 02 1F            JSR   ONEKEY
1117   1F71 D0 07               BNE   KEYIN      ; A=0 NO KEY
1118   1F73 E0 27               CPX   #$27       ; TEST FOR DIGIT 2
1119   1F75 D0 F5               BNE   GETKE5
1120   1F77 A9 15               LDA   #$15       ; 15=NOKEY
1121   1F79 60                  RTS   
1122   1F7A A0 FF       KEYIN   LDY   #$FF
1123   1F7C 0A          KEYIN1  ASL   A          ; SHIFT LEFT
1124   1F7D B0 03               BCS   KEYIN2     ; UNTIL Y=KEY NUM
1125   1F7F C8                  INY   
1126   1F80 10 FA               BPL   KEYIN1
1127   1F82 8A          KEYIN2  TXA   
1128   1F83 29 0F               AND   #$0F       ; MASK MSD
1129   1F85 4A                  LSR   A          ; DIVIDE BY 2
1130   1F86 AA                  TAX   
1131   1F87 98                  TYA   
1132   1F88 10 03               BPL   KEYIN4
1133   1F8A 18          KEYIN3  CLC   
1134   1F8B 69 07               ADC   #$07       ; MULT (X-1) TIMES A
1135   1F8D CA          KEYIN4  DEX   
1136   1F8E D0 FA               BNE   KEYIN3
1137   1F90 60                  RTS
1138   1F91             ;

1200   1FE7             ;       TABLE HEX TO 7 SEGMENT
1201   1FE7             ;              0   1   2   3   4   5   6   7  
1202   1FE7 BF 86 DB CF TABLE   .BYTE  $BF,$86,$DB,$CF,$E6,$ED,$FD,$87
1202   1FEB E6 ED FD 87 
1203   1FEF             ;              8   9   A   B   C   D   E   F   
1204   1FEF FF EF F7 FC         .BYTE  $FF,$EF,$F7,$FC,$B9,$DE,$F9,$F1
1204   1FF3 B9 DE F9 F1 
1205   1FF7             ;