85 lines
4.7 KiB
Plaintext
85 lines
4.7 KiB
Plaintext
0000- 4
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0000- 5 * ----------------------------------------------------------------------
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0000- 6 * SAMPLE PROGRAM AS FOUND IN THE BOOK "6502 APPLICATIONS BOOK" BY RODNEY
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0000- 7 * ZAKS, IT IS A SOFTWARE METHOD OF CONTROLLING SOUND DURATION.ADAPTED FOR
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0000- 8 * THE KIM-1 WITH THE 6502 PROJECT PLATFORM BOARD / COVOX PROJECT BOARD.
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0000- 9 *
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0004- 10 CURRENT .EQ $04
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0000- 11
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6000- 12 VIA .EQ $6000 SBC VIA
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6000- 13 ORB .EQ VIA PORT B DATA
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6001- 14 ORA .EQ VIA+1 PORT A DATA
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6002- 15 DDRB .EQ VIA+2 PORT B DATA-DIRECTION
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6003- 16 DDRA .EQ VIA+3 PORT A DATA-DIRECTION
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0000- 17
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4000- 18 PP_VIA .EQ $4000 PP VIA
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4000- 19 PP_ORB .EQ PP_VIA
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4001- 20 PP_ORA .EQ PP_VIA+1
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4002- 21 PP_DDRB .EQ PP_VIA+2
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4003- 22 PP_DDRA .EQ PP_VIA+3
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0000- 23
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8000- 24 .OR $8000
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8000- 25 .TA $0000
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8000-A9 FF 26 ( 2) START LDA #$FF SET SBC VIA PORT B AS OUTPUTS
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8002-8D 02 60 27 ( 4) STA DDRB
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8005- 28
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8005-A9 7F 29 ( 2) LDA #%1111111 PORT A, USED TO LOAD VALUES FOR LED-S
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8007-8D 03 40 30 ( 4) STA PP_DDRA INTO LATCHES.
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800A-A9 1F 31 ( 2) LDA #%0011111 PORT B, USED FOR CONTROL LINES AS WELL AS
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800C-8D 02 40 32 ( 4) STA PP_DDRB SWITCHES.
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800F- 33
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800F-A9 55 34 ( 2) LDA #$55
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8011-85 04 35 ( 2) STA CURRENT
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8013- 36
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8013-A9 3F 37 ( 2) OUTPUT LDA #%00111111 DISABLE ALL LAYERS
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8015-8D 00 40 38 ( 4) STA PP_ORB
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8018- 39
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8018-A9 FF 40 ( 2) LDA #$FF ALTERNATE LEDS ON
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801A-45 04 41 ( 3) EOR CURRENT THE LAYERS BY DOING
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801C-85 04 42 ( 2) STA CURRENT AN EXCLUSIVE OR ON
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801E-8D 01 40 43 ( 4) STA PP_ORA THE CURRENT VALUE,
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8021-20 53 80 44 ( 6) JSR LATCH THEN LATCH THEM.
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8024- 45
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8024-20 5E 80 46 ( 6) JSR DELAY
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8027-A9 3B 47 ( 2) LDA #%00111011
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8029-8D 00 40 48 ( 4) STA PP_ORB
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802C-8D 00 60 49 ( 4) STA ORB
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802F- 50
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802F-20 5E 80 51 ( 6) JSR DELAY
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8032-A9 37 52 ( 2) LDA #%00110111
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8034-8D 00 40 53 ( 4) STA PP_ORB
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8037-8D 00 60 54 ( 4) STA ORB
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803A- 55
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803A-20 5E 80 56 ( 6) JSR DELAY
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803D-A9 2F 57 ( 2) LDA #%00101111
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803F-8D 00 40 58 ( 4) STA PP_ORB
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8042-8D 00 60 59 ( 4) STA ORB
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8045- 60
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8045-20 5E 80 61 ( 6) JSR DELAY
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8048-A9 1F 62 ( 2) LDA #%00011111
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804A-8D 00 40 63 ( 4) STA PP_ORB
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804D-8D 00 60 64 ( 4) STA ORB
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8050- 65
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8050-4C 13 80 66 ( 3) JMP OUTPUT
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8053- 67
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8053-A9 3C 68 ( 2) LATCH LDA #%00111100 LATCH VALUES BY
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8055-8D 00 40 69 ( 4) STA PP_ORB TAKING THE CONTROLS
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8058-A9 3F 70 ( 2) LDA #%00111111 LOW AND THEN
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805A-8D 00 40 71 ( 4) STA PP_ORB HIGH AGAIN.
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805D-60 72 ( 6) RTS
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805E- 73
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805E- 74
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805E-A2 FF 75 ( 2) DELAY LDX #$FF LOAD DELAY VALUE INTO X
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8060-CA 76 ( 2) LPDLY DEX DECREMENT X
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8061-D0 FD 77 (2**) BNE LPDLY
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8063-60 78 ( 6) RTS
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8064- 79
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8064- 80
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8064- 81 * ---------------------------------------------------------
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8064- 82 * STORE VECTORS AT END OF EPROM.
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FFFA- 83 .OR $FFFA
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FFFA- 84 .TA $7FFA
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FFFA-00 80 85 .DA START NMI VECTOR
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FFFC-00 80 86 .DA START RESET VECTOR
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FFFE-00 80 87 .DA START IRQ VECTOR
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