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108 lines
5.6 KiB

  1. PAL20X10 PAL DESIGN SPECIFICATION
  2. VP3 BIRKNER/KAMZI/UDI 7/9/81
  3. SCAN/LINE GENERATOR
  4. MMI SUNNYVALE, CALIFORNIA
  5. CK /CHAR5 /CHAR4 /CHAR3 /CHAR2 /INITS /H255 /WRITE /TSYNC /CHAR1 /CHAR0 GND
  6. /OC /LINE4 /LINE3 /SYNC /SCAN3 SCAN2 SCAN1 SCAN0 /LINE2 /LINE1 /LINE0 VCC
  7. /SCAN0 := INITS ;INITIALIZE
  8. + /INITS*/SCAN0 ;HOLD
  9. :+:/INITS*H255 ;INCREMENT
  10. /SCAN1 := INITS ;INITIALIZE
  11. + /INITS*/SCAN1 ;HOLD
  12. :+:/INITS*H255*SCAN0 ;INCREMENT
  13. /SCAN2 := INITS ;INITIALIZE
  14. + /INITS*/SCAN2 ;HOLD
  15. :+:/INITS*H255*SCAN0*SCAN1*/SCAN3 ;INC IN MODULUS 12
  16. SCAN3 := /INITS*SCAN3 ;HOLD
  17. + /INITS*H255*LINE4*LINE2*LINE0 ;DETECT SCAN LINE 260
  18. *SCAN2*SCAN1*SCAN0 ;FOR VERTICAL RETRACE
  19. :+:/INITS*H255*SCAN0*SCAN1*SCAN2 ;INCREMENT
  20. + /INITS*H255*SCAN3*SCAN1*SCAN0 ;MODULE 12 CORRECTION
  21. ;INITIAL WHEN INITS=H
  22. LINE0 := /INITS*LINE0 ;HOLD
  23. + /TSYNC ;TEST SYNC
  24. :+:/INITS*H255*SCAN3*SCAN1*SCAN0 ;INCREMENT
  25. + /INITS*H255*LINE4*LINE2*LINE0 ;DETECT LINE 21 7/12
  26. *SCAN2*SCAN1*SCAN0 ;FOR VERTICAL RETRACE
  27. LINE1 := /INITS*LINE1 ;HOLD
  28. + /TSYNC ;TEST SYNC
  29. :+:/INITS*H255*SCAN3*SCAN1*SCAN0*LINE0 ;INCREMENT
  30. LINE2 := /INITS*LINE2 ;HOLD
  31. + /INITS*LINE2 ;EXTEND
  32. :+:/INITS*H255*SCAN3*SCAN1*SCAN0*LINE0*LINE1 ;INCREMENT
  33. *SCAN2*SCAN1*SCAN0 ;FOR VERTICAL RETRACE
  34. LINE3 := /INITS*LINE3 ;HOLD
  35. + /INITS*LINE3 ;EXTEND
  36. :+:/INITS*H255*SCAN3*SCAN1*SCAN0 ;INCREMENT
  37. *LINE2*LINE1*LINE0
  38. LINE4 := /INITS*LINE4 ;HOLD
  39. + /TSYNC ;TEST SYNC
  40. :+:/INITS*H255*SCAN3*SCAN1*SCAN0 ;INCREMENT
  41. *LINE3*LINE2*LINE1*LINE0
  42. + /INITS*H255*LINE4*LINE2*LINE0 ;DETECT LINE 21 7/12
  43. *SCAN2*SCAN1*SCAN0 ;FOR VERTICAL RETRACE
  44. SYNC := CHAR5*CHAR4*/CHAR3*CHAR2*/WRITE ;CHAR 52-55 HORIZ SYNC
  45. + LINE0*LINE1*/LINE2*LINE4*/SCAN2*/SCAN3*SYNC ;VERTICAL SYNC
  46. :+: LINE0*LINE1*/LINE2*LINE4*/SCAN2*/SCAN3*SYNC ;WHEN LINE=19 SCAN 0-3
  47. *CHAR5*CHAR4*/CHAR3*/CHAR2 ;AND CHAR 48-51
  48. FUNCTION TABLE
  49. CK CHARS CHAR4 CHAR3 CHAR2 CHAR1 CHAR0 TSYNC INITS H255 WRITE
  50. /OC LINE4 LINE3 LINE2 LINE1 LINE0 SYNC SCAN3 SCAN2 SCAN1 SCAN0
  51. ; T I W
  52. ; S N H R S
  53. ; Y I 2 I / Y
  54. ; C CHAR N T 5 T O LINE N SCAN
  55. ; K 543210 C S 5 E C 43210 C 3210 COMMENTS
  56. ------------------------------------------------------------------------
  57. C XXXXXX H H X X L LLLLL X LLLL INITIALIZE COUNTERS
  58. C XXXXXX H L H X L LLLLL X LLLH INC SCAN
  59. C XXXXXX H L H X L LLLLL X LLHL INC SYNC
  60. C XXXXXX H L H X L LLLLL X LLHH INC SYNC
  61. C XXXXXX H L H X L LLLLL X LHLL INC SCAN
  62. C XXXXXX H L H X L LLLLL X LHLH INC SCAN
  63. C XXXXXX H L H X L LLLLL X LHHL INC SCAN
  64. C XXXXXX H L H X L LLLLL X LHHH INC SCAN
  65. C XXXXXX H L H X L LLLLL X HLLL INC SCAN
  66. C XXXXXX H L H X L LLLLL X HLLH INC SCAN
  67. C XXXXXX H L H X L LLLLL X HLHL INC SCAN
  68. C XXXXXX H L H X L LLLLL X HLHH INC SCAN
  69. C XXXXXX H L H X L LLLLH X LLLL INC LINE, INC SCAN MODULE 12
  70. C XXXXXX H L H X L LLLLH X LLLH LINE = 1, INC SCAN
  71. C XXXXXX H L H X L LLLLH X LLHL LINE = 1, INC SCAN
  72. C XXXXXX H L H X L LLLLH X LLHH LINE = 1, INC SCAN
  73. C XXXXXX H H X X L LLLLL X LLLL INITIALIZE COUNTERS
  74. C HHLLXX L L L X L HLLHH L LLLL LINE = 19, FOR TESTING VERTIC SYNC
  75. C HHLLXX H L H X L HLLHH L LLLH VERTICAL SYNC
  76. C HHLLXX H L H X L HLLHH L LLHL VERTICAL SYNC
  77. C HHLLXX H L H X L HLLHH L LLHH VERTICAL SYNC
  78. C HHLLXX H L H X L HLLHH L LHLL INC SCAN
  79. C HHLLXX H L H X L HLLHH L LHLH INC SCAN
  80. C HHLHXX H L L L L XXXXX H XXXX HORIZONTAL SYNC
  81. ------------------------------------------------------------------------
  82. DESCRIPTION
  83. EACH CHARACTER ON THE SCREEN CONSISTS OF 12 DOT LINES: 7 LINES FOR THE
  84. CHARACTER AND 5 LINES FOR SPACE BETWEEN CHARACTERS.
  85. "SCAN" IS A MODULE 12 COUNTER THAT COUNTS THE NUMBER OF THE DOT LINES FOR
  86. EACH CHARACTER.
  87. "LINE" COUNTS THE NUMBER OF THE CHARACTER LINES. EACH CHARACTER LINE IS
  88. 12 SCAN LINES. THE COUNTER COUNTS UNTIL 21 ALTHOUGH ONLY 16 LINES ARE
  89. VISIBLE ON THE SCREEN.
  90. THE HORIZONTAL SYNC PULSES ARE GIVEN IN EVERY SCANNED LINE BETWEEN
  91. CHAR 52 AND 55. THE VERTICAL SYNC PULSE IS GIVEN WHEN THE LINE COUNT IS 19,
  92. SCAN IS BETWEEN 0 AND 3, AND CHAR IS BETWEEN 48 AND 51.