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  1.                   Floppy Backup of large files
  2.                     BACKUP.COM & COPYRND.COM
  3.                            (Z80 only)
  4.  
  5. Backinτá u≡á largσá file≤ froφ winchestσ disc≤ caε bσá ßá probleφ ì
  6. unde≥ CP/═ iµ thσ filσ sizσ i≤ greate≥ thaε thσ tota∞ capacit∙ oµ ì
  7. a floppy disk.
  8.  
  9. ┴á numbe≥ oµ proprietor∙ utilitie≤ arσ availablσ fo≥á backinτá u≡ ì
  10. largσá files¼á howeve≥ ß systeφ whicΦ create≤ standarΣ CP/═ file≤ ì
  11. oεá thσá disπá ha≤á attraction≤ a≤á wel∞á a≤á providinτá completσ ì
  12. flexibilit∙ ove≥ an∙ wincheste≥ disδ anΣ flopp∙ disδ combination.
  13.  
  14. Rathe≥á thaεá concoc⌠ somσ uniquσ filσ structurσ fo≥á thσá backu≡ ì
  15. copies¼á thσá BACKU╨ utilit∙ exploit≤ thσ methoΣ useΣ b∙ CP/═á t∩ ì
  16. managσ largσ files« T∩ thσ applicatioε prograφ anΣ t∩ man∙ users¼ ì
  17. ß largσ CP/═ filσ appear≤ a≤ ß singlσ file«á Iε fac⌠ thσ physica∞ ì
  18. CP/═ file≤ arσ limiteΣ t∩ 16δ unde≥ CP/═ 1.4¼á anΣ 16k¼ 32k¼ 64k¼ ì
  19. o≥á 128δá unde≥á CP/═ 2.2«á CP/═á overcome≤á thi≤á limitatioεá b∙ ì
  20. creatinτá ßá numbe≥á oµá file≤ witΦ thσ samσá filenamσá bu⌠á witΦ ì
  21. differen⌠ exten⌠ numbers«á AlthougΦ DIR¼á fo≥ example¼ onl∙ show≤ ì
  22. onσá file¼á therσá ma∙ bσ man∙ file≤ fo≥ thσ onσá filename«á (Thσ ì
  23. CAT.CO═ utilit∙ iε thσ U╦ Librar∙ wil∞ demonstratσ this.)
  24.  
  25. Thσá BACKU╨á utilit∙ overcome≤ thσ sizσ probleφá b∙á copyinτá no⌠ ì
  26. files¼á bu⌠á extent≤ oµ files«á A≤ thesσ mus⌠ alway≤ bσ les≤ thaε ì
  27. thσ capacit∙ oµ ß flopp∙ diskette¼á largσ file≤ arσ easil∙ backeΣ ì
  28. u≡ b∙ copyinτ eacΦ exten⌠ oε multiplσ disks«á BACKU╨ wil∞ cop∙ a≤ ì
  29. man∙ extent≤ a≤ possiblσ ont∩ eacΦ diskettσ beforσ promptinτá thσ ì
  30. use≥ t∩ changσ disks.
  31.  
  32. Thσ exten⌠ sizσ i≤ ß functioε oµ thσ disδ blocksizσ (1k¼á 2k¼ 4k¼ ì
  33. etc.⌐á anΣ whethe≥ thσ disδ capicit∙ i≤ les≤ thaε 25╢á blocksize≤ ì
  34. or not. The following example illustrates this.
  35.  
  36. For example:
  37. ------------
  38.                       20 M Byte           800 K Byte 
  39.                       Winchester          floppy disc
  40. Blocksize:               16k                   4k
  41. Capacity:              1280 blks             200 blks
  42. Extent size:            128k                  64k
  43.  
  44. File size:                8M                  8M
  45. No extents:              64                  128
  46. No discs:                 1                   11
  47.  
  48. Note║á CP/═á Plu≤ i≤ requireΣ t∩ suppor⌠ ß disπ capacit∙ oµ 2░á ═ ì
  49. bytes«á Unde≥ CP/═  2.2¼ thσ disπ woulΣ requirσ partitioninτ int∩ ì
  50. smalle≥ units.
  51.  
  52.  
  53. BACKU╨á ha≤ iε thi≤ examplσ createΣ 12╕ standarΣ CP/═ files¼á bu⌠ ì
  54. spreaΣá ove≥ 1▒ disks«á I⌠ i≤ wortΦ observinτ tha⌠ ß DI╥á oµá thσ ì
  55. disc≤á wil∞ producσ N╧ FILE╙ excep⌠ oε thσ firs⌠ disk«á Howeve≥ ß ìèSTA╘ unde≥ CP/═ 2.2¼á o≥ ß DI╥ [SI▌ unde≥ CP/═ Plu≤ wil∞ sho≈ thσ ì
  56. filenamσ oε eacΦ disk«á ┴ STA╘ $╙ wil∞ als∩ sho≈ that¼ excep⌠ fo≥ ì
  57. thσ firs⌠ disc¼ thσ sizσ oµ thσ file≤ i≤ les≤ thaε thσ maximum.
  58.  
  59. BACKU╨á ha≤á utiliseΣá onσ oµ thσ lesse≥ knowε feature≤á oµá CP/═ ì
  60. whicΦá i≤ it≤ abilit∙ t∩ suppor⌠ file≤ witΦ 'HOLES'«á ┴á HOL┼á i≤ ì
  61. eithe≥á ß non-existen⌠ extent¼á o≥ aε unuseΣ datß blocδ withiε aε ì
  62. extent«á User≤ oµ randoφ acces≤ ma∙ havσ comσ acros≤ thi≤ featurσ ì
  63. accidently.
  64.  
  65. Copying HOLES
  66. -------------
  67.  
  68. Ofteε thσ firs⌠ timσ ß use≥ experience≤ file≤ witΦ HOLE╙ i≤á wheε ì
  69. PI╨á fail≤ t∩ cop∙ ß file«á PI╨ unfortunatel∙ stop≤ a⌠ thσá firs⌠ ì
  70. HOLE and assumes this is the end of the file.
  71. ì
  72. Thσá utilit∙ COPYRN─ overcome≤ thi≤ limitatioε anΣ copie≤ ßá filσ ì
  73. froφ begininτ t∩ thσ enΣ skippinτ ove≥ an∙ holes« Howeve≥ COPYRN─ ì
  74. a≤ firs⌠ releaseΣ iε thσ U╦ Librar∙ eraseΣ thσ filσ iµ i⌠ existeΣ ì
  75. oεá thσá targe⌠ device«á Thσ late≥ releasσ oµá COPYRN─á ha≤á beeε ì
  76. modifieΣ t∩ confirφ thσ erasσ s∩ tha⌠ i⌠ caε bσ useΣ t∩ combinσ ß ì
  77. filσ spreaΣ ove≥ man∙ diskettes.
  78.  
  79. Thu≤á an∙ filσ whicΦ ha≤ beeε backeΣ u≡ witΦ thσá BACKU╨á utilit∙ ì
  80. anΣ spreaΣ ove≥ morσ thaε onσ disc¼ canno⌠ bσ recovereΣ witΦ PIP« ì
  81. Instead the utility COPYRND must be used.
  82.  
  83.  
  84. WILDCARDS
  85. ---------
  86.  
  87. BotΦá BACKU╨ anΣ COPYRN─ suppor⌠ wilΣ cards«á Thu≤ BACKU╨ caεá bσ ì
  88. useΣá t∩ backu≡ al∞ file≤ oε ß wincheste≥ disc¼á anΣ COPYRN─ wil∞ ì
  89. restore them.
  90.  
  91. IMPORTANT
  92. ---------
  93.  
  94. Thσá BACKU╨á anΣ COPYRN─ havσ beeε developeΣ fo≥ usσá unde≥á botΦ ì
  95. CP/═ 2.▓ anΣ CP/═ Plus¼á bu⌠ the∙ havσ no⌠ beeε thoroughl∙ testeΣ ì
  96. under CP/M 2.2 - please inform me of any bugs thereby found.
  97.  
  98. ┴á Z8░ machinσ i≤ assumed¼á however¼á thσ program≤ caε easil∙á bσ ì
  99. converteΣ int∩ ß 8080/808╡ versioε a≤ onl∙ thσ 808░ register≤ arσ ì
  100. used«á Thσá program≤ werσ assembleΣ witΦ Microsof⌠ M8░ anΣ linkeΣ ì
  101. witΦ Digita∞ ResearcΦ LINK.
  102.  
  103. D. Powys-Lybbe
  104. 18th August 1984
  105. ================
  106.  
  107.