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  1.                                Z-System Corne≥ (c)
  2.                                  by Jay Sage
  3.                         The Computer Journal, Issue 43
  4.                           Reproduced with permission
  5.                            of author and publisher
  6.  
  7.  
  8.    Thi≤ átimσ ám∙ ácolumε ái≤ goinτ t∩ bσ quitσ áshort« á Iε áresponsσ át∩ ám∙ ì
  9. requests¼ áß numbe≥ oµ author≤ havσ submitteΣ somσ ver∙ interestinτ áarticles¼ ì
  10. bu⌠ átherσ ha≤ no⌠ beeε enougΦ spacσ t∩ prin⌠ them«  ╔ wan⌠ t∩ makσ surσ átha⌠ ì
  11. thosσ áarticle≤ áarσ no⌠ delayeΣ further«  Onσ oµ theφ i≤ oε áthσ ásuperΓ áLS╚ ì
  12. histor∙ shel∞ b∙ RoΓ Friefeld¼ wh∩ ha≤ contributeΣ quitσ ß numbe≥ oµ excellen⌠ ì
  13. ┌-Systeφ áprogram≤ (SALIAS¼ VCOMP¼ anΣ BCOMP¼ t∩ namσ ß few)«  Yo⌡ shoulΣ áno⌠ ì
  14. mis≤ tha⌠ article.
  15.  
  16.    Afte≥ áworkinτ áfirs⌠ áwitΦ thσ origina∞ ┌-Systeφ áhistor∙ áshel∞ á(HS╚ áb∙ ì
  17. Michae∞ áRubenstein⌐ anΣ theε witΦ EAS┼ b∙ Pau∞ Pomerleau¼ i⌠ occurreΣ át∩ ámσ ì
  18. tha⌠ ái⌠ áwoulΣ ábσ eveε nice≥ t∩ havσ ß ful∞-screeε histor∙ áshell« á Wha⌠ á╔ ì
  19. envisioneΣ áwa≤ bringinτ thσ ful∞ resource≤ oµ ß wordprocesso≥ t∩ bea≥ oε áthσ ì
  20. commanΣ átranscript¼ ás∩ átha⌠ ácommand≤ coulΣ ábσ áeasil∙ áviewed¼ ámodified¼ ì
  21. reordered¼ áanΣ áregrouped«  Iµ thσ histor∙ filσ werσ ß standarΣ áASCI╔ áfile¼ ì
  22. theε áonσ ácoulΣ ámassagσ áthσ filσ witΦ ß standarΣ áedito≥ áo≥ áeveε ápreparσ ì
  23. 'historyº script≤ iε advancσ fo≥ specia∞ purposes.
  24.  
  25.    Afte≥ áseeinτ áthσ splendiΣ ful∞-screeε worδ RoΓ FriefelΣ haΣ donσ áiε áhi≤ ì
  26. SALIA╙ á(Screeε áALIA╙ editor)¼ ╔ askeΣ hiφ iµ hσ woulΣ takσ oε áthσ átasδ áoµ ì
  27. writinτ ásucΦ áß histor∙ shell«  Hσ did¼ anΣ hσ ha≤ donσ ß ásplendiΣ ájob« á ╔ ì
  28. would¼ átherefore¼ álikσ át∩ ápublicl∙ átakσ ácredi⌠ áfo≥ átha⌠ áal∞-importan⌠ ì
  29. managemen⌠ skil∞ oµ askinτ thσ righ⌠ persoε t∩ d∩ ß job!
  30.  
  31.  
  32.                           Softwarσ Updatσ Service
  33.  
  34.    Whilσ Echeloε wa≤ stil∞ iε busines≤ marketinτ thσ ┌-System¼ the∙ offereΣ áß ì
  35. ver∙ ánicσ áproduc⌠ calleΣ SU╙ o≥ Softwarσ Updatσ Service« á Peoplσ áwh∩ áhavσ ì
  36. modem≤ anΣ ß nearb∙ ┌-Nodσ o≥ RCP/═ systeφ generall∙ d∩ no⌠ havσ mucΦ átroublσ ì
  37. pickinτ áu≡ áthσ lates⌠ release≤ oµ publiπ-domaiε ┌-Systeφ áanΣ ágenera∞ áCP/═ ì
  38. software« á However¼ fo≥ thosσ wh∩ d∩ no⌠ havσ modem≤ o≥ fo≥ whoφ thσ áneares⌠ ì
  39. ┌-Nodσ ái≤ aε expensivσ lonτ-distancσ call¼ obtaininτ ß ful∞ se⌠ áoµ á┌-Systeφ ì
  40. tool≤ áo≥ keepinτ u≡ witΦ ne≈ release≤ i≤ mucΦ morσ difficult«    Thσ áEcheloε ì
  41. SU╙ áwa≤ ádesigneΣ t∩ solvσ tha⌠ probleφ b∙ makinτ thσ materia∞ áavailablσ áoε ì
  42. diskettσ b∙ mail«  I⌠ wa≤ ß disδ subscriptioε service¼ anΣ roughl∙ ever∙ montΦ ì
  43. subscriber≤ woulΣ ge⌠ ß diskettσ ful∞ oµ publiπ-domaiε software.
  44.  
  45.    ╔ áaφ happ∙ t∩ announcσ tha⌠ SU╙ i≤ cominτ back¼ thank≤ t∩ thσ áurginτ áanΣ ì
  46. energ∙ oµ Chri≤ McEwen¼ syso≡ oµ thσ Socrate≤ ┌-Nodσ (#32)¼ iε Plainfield¼ NJ«  ì
  47. Chri≤ anΣ Bil∞ Tishey¼ togethe≥ witΦ Sagσ Microsystem≤ East¼ wil∞ bσ áofferinτ ì
  48. aε áeveε morσ extensivσ servicσ thaε Echelon's«  Bil∞ Tishey¼ a≤ mos⌠ áoµ áyo⌡ ì
  49. know¼ áha≤ áfo≥ ásomσ timσ beeε maintaininτ ß ácompletσ ácataloτ áoµ á┌-Systeφ ì
  50. program≤ á(ZFILESnn.LST⌐ anΣ ß compendiuφ oµ HL╨ file≤ coverinτ al∞ áoµ áthem«  ì
  51. A⌠ áfrequen⌠ áintervals¼ áBil∞ release≤ aε updatσ LB╥ witΦ al∞ áthσ áne≈ áhel≡ ì
  52. files« á Now¼ áiε áadditioε t∩ tha⌠ service¼ Bil∞ áwil∞ ábσ áputtinτ átogethe≥ ìèdiskette≤ witΦ thσ softwarσ a≤ wel∞ a≤ thσ documentation.
  53.  
  54.    Thi≤ ámean≤ tha⌠ yo⌡ wil∞ bσ ablσ t∩ purchasσ diskette≤ witΦ áthσ ácompletσ ì
  55. se⌠ áoµ ┌-Systeφ program≤ and/o≥ subscribσ t∩ ß monthl∙ updatσ service« á Bil∞ ì
  56. anΣ áChri≤ wil∞ bσ handlinτ mos⌠ oµ thσ diskettσ production╗ SM┼ áwil∞ áhandlσ ì
  57. thσ order≤ anΣ bookkeepinτ anΣ wil∞ producσ diskette≤ iε thσ fe≈ format≤ átha⌠ ì
  58. Chri≤ anΣ Bil∞ canno⌠ handlσ (8ó IB═ SSSD¼ NorthSta≥ harΣ-sector¼ anΣ áAmstraΣ ì
  59. 3").
  60.  
  61.    Wσ havσ no⌠ ye⌠ workeΣ ou⌠ al∞ thσ pricinτ detail≤ fo≥ al∞ thσ options¼ bu⌠ ì
  62. b∙ áthσ timσ yo⌡ arσ readinτ thi≤ column¼ wσ wil∞ havσ flyer≤ áavailablσ áwitΦ ì
  63. al∞ áthσ information«  Jus⌠ dro≡ mσ ß lette≥ o≥ postcard¼ o≥ leavσ áß ámessagσ ì
  64. fo≥ mσ iε an∙ oµ thσ way≤ indicateΣ iε thσ sideba≥ t∩ thi≤ column¼ anΣ ╔ áwil∞ ì
  65. ge⌠ ß flye≥ t∩ you«  T∩ givσ yo⌡ somσ ideß oµ wha⌠ wσ arσ talkinτ about¼ ß á╢-ì
  66. montΦ SU╙ subscriptioε t∩ ß U╙ addres≤ wil∞ probabl∙ bσ $4╕ ($╕ pe≥ disk⌐ áanΣ ì
  67. ß year'≤ subscriptioε $7▓ ($╢ pe≥ diskette)«  A≤ yo⌡ caε see¼ wσ arσ tryinτ t∩ ì
  68. kee≡ thσ pricσ ver∙ low«  Wσ reall∙ wan⌠ al∞ oµ yo⌡ t∩ bσ ablσ t∩ ge⌠ anΣ áusσ ì
  69. al∞ thesσ wonderfu∞ programs.
  70.  
  71.  
  72.                           Full∙ Customizinτ NZCOM
  73.  
  74.    M∙ átechnica∞ topiπ fo≥ thi≤ timσ wil∞ bσ abou⌠ designinτ full∙ ácustomizeΣ ì
  75. NZCO═ á┌-Systems«  ╔ havσ alway≤ beeε satisfieΣ witΦ thσ system≤ tha⌠ ácaε ábσ ì
  76. produceΣ s∩ easil∙ usinτ thσ MKZC═ (MaKσ nZCoM⌐ men⌡-driveε utility¼ anΣ s∩ á╔ ì
  77. neve≥ áreall∙ ádelveΣ áint∩ áthi≤ areß ver∙ much«  Abou⌠ ß áweeδ áo≥ ás∩ áago¼ ì
  78. however¼ áDavσ Goodmaε brough⌠ thσ probleφ t∩ me«  Hσ ha≤ ß NorthSta≥ áHorizoε ì
  79. witΦ áaε adΣ-oε harΣ disk¼ anΣ thσ operatinτ systeφ ha≤ ß RO═ stucδ ásomewherσ ì
  80. iε áthσ middlσ oµ thσ addres≤ space«  Tha⌠ lef⌠ somσ disjoin⌠ block≤ áoµ áfreσ ì
  81. memory¼ áanΣ Davσ reall∙ wanteΣ t∩ makσ usσ oµ al∞ thσ space«  ╔ tolΣ áhiφ ám∙ ì
  82. standarΣ answe≥ t∩ tha⌠ problem.
  83.  
  84.    Iε sectioε ╡ (especiall∙ subsectioε 5.2.3⌐ oµ thσ NZCO═ manual¼ ╔ poin⌠ ou⌠ ì
  85. tha⌠ thσ NZCO═ systeφ i≤ defineΣ b∙ ß descripto≥ filσ anΣ tha⌠ thi≤ filσ (witΦ ì
  86. typσ áZCM⌐ ái≤ ß purσ ASCI╔ filσ tha⌠ caε bσ editeΣ witΦ one'≤ áfavoritσ átex⌠ ì
  87. editor«  Thσ manua∞ recommend≤ tha⌠ everyonσ makσ certaiε change≤ s∩ tha⌠ áthσ ì
  88. descripto≥ wil∞ properl∙ reflec⌠ thσ user'≤ hardwarσ environment¼ sucΦ a≤ áthσ ì
  89. disδ ádrive≤ áavailablσ anΣ thσ characteristic≤ oµ thσ ásystem'≤ áprinte≥ áanΣ ì
  90. terminal.
  91.  
  92.    ╔ ádiΣ áno⌠ áactuall∙ ácomσ ou⌠ anΣ sa∙ i⌠ áexplicitly¼ ábu⌠ átherσ ái≤ áaε ì
  93. implicatioε tha⌠ othe≥ value≤ iε thσ ZC═ filσ caε als∩ bσ changed«  Thσ átrutΦ ì
  94. is¼ ╔ believe¼ tha⌠ ╔ avoideΣ thi≤ subjec⌠ iε par⌠ becausσ ╔ wa≤ no⌠ áentirel∙ ì
  95. surσ whicΦ value≤ coulΣ anΣ whicΦ value≤ coulΣ no⌠ bσ changed«  M∙ ásuggestioε ì
  96. t∩ Davσ Goodmaε wa≤ tha⌠ hσ experimen⌠ witΦ designinτ ß custoφ memor∙ ma≡ áfo≥ ì
  97. hi≤ ásystem¼ edi⌠ thσ value≤ int∩ thσ ZC═ file¼ anΣ seσ wha⌠ happeneΣ wheε áhσ ì
  98. trieΣ t∩ loaΣ it.
  99.  
  100.    Dave'≤ árepor⌠ ábacδ át∩ áme¼ no≈ confirmeΣ b∙ m∙ áowε áexperiment≤ áoε ám∙ ì
  101. Televide∩ á803H¼ áindicateΣ átha⌠ áAL╠ ávalue≤ ácaε ábσ áchanged« á Thσ ááonl∙ ì
  102. requiremen⌠ ái≤ átha⌠ áthσ ávalue≤ áprovidσ áß ámemor∙ áma≡ áwitΦ án∩ ámodule≤ ì
  103. overlapping« á Wheε áyo⌡ áusσ MKZC═ t∩ desigε thσ system¼ i⌠ átake≤ áove≥ áthσ ìèresponsibilit∙ áfo≥ ágeneratinτ áß ávaliΣ memor∙ map╗ iµ áyo⌡ ád∩ áthσ ádesigε ì
  104. yourself¼ yo⌡ bette≥ bσ careful.
  105.  
  106. ┴ Helpfu∞ Utility
  107.  
  108.    Thi≤ ásuggest≤ ß ver∙ nicσ utilit∙ prograφ tha⌠ somσ thoughtfu∞ sou∞ ácoulΣ ì
  109. contributσ át∩ áthσ community«  Thi≤ utilit∙ (let'≤ cal∞ i⌠ ZMAP⌐ migh⌠ ád∩ áß ì
  110. numbe≥ oµ helpfu∞ things«  First¼ i⌠ coulΣ display¼ perhap≤ iε somσ ágraphica∞ ì
  111. o≥ semΘ-graphica∞ way¼ thσ memor∙ ma≡ oµ ß ┌-System¼ thσ onσ actuall∙ árunninτ ì
  112. o≥ áonσ specifieΣ iε thσ forφ oµ ß ZC═ o≥ EN╓ filσ (anΣ maybσ eveε thσ áZ3PLU╙ ì
  113. descripto≥ áfilσ áoµ typσ Z3P)«  Presen⌠ utilities¼ sucΦ a≤ SHO╫ á(ZSHOW⌐ áanΣ ì
  114. Z3LOC¼ lis⌠ thσ modulσ addresse≤ iε ß fixeΣ order¼ no⌠ iε orde≥ oµ áincreasinτ ì
  115. memor∙ áaddress«  Thu≤ the∙ arσ no⌠ ver∙ helpfu∞ iε determininτ iµ átherσ áarσ ì
  116. gap≤ áo≥ áoverlap≤ iε thσ map«  Ideally¼ ZMA╨ woulΣ flaτ an∙ sucΦ ádefect≤ áo≥ ì
  117. potentia∞ defect≤ iε thσ ma≡ s∩ tha⌠ the∙ coulΣ bσ correcteΣ beforσ the∙ causσ ì
  118. harm.
  119.  
  120.    Thσ fina∞ iteφ oε m∙ wishlis⌠ ¡¡ anΣ thi≤ migh⌠ bette≥ bσ implementeΣ iε áß ì
  121. second¼ áindependen⌠ prograφ (ZDESIG╬ perhaps⌐ ¡¡ woulΣ bσ ß genera∞ á┌-Systeφ ì
  122. designer¼ alonτ thσ line≤ oµ MKZC═ bu⌠ withou⌠ it≤ restrictions«  Onσ woulΣ bσ ì
  123. ablσ t∩ specif∙ thσ orde≥ oµ al∞ thσ module≤ iε memor∙ anΣ thei≥ sizes«  Giveε ì
  124. thσ áhighes⌠ memor∙ addres≤ available¼ thσ prograφ woulΣ theε figurσ áou⌠ áanΣ ì
  125. displa∙ áthσ memor∙ map«  Onσ shoulΣ bσ ablσ easil∙ t∩ alte≥ thσ orde≥ oµ áthσ ì
  126. modules¼ anΣ onσ shoulΣ bσ ablσ t∩ overridσ specifiπ addresse≤ t∩ creatσ ágap≤ ì
  127. iµ ánecessar∙ (bu⌠ no⌠ t∩ forcσ overlaps)«  Oncσ thσ desireΣ systeφ áha≤ ábeeε ì
  128. designed¼ áthσ áprograφ áshoulΣ writσ ou⌠ ß ZC═ o≥ EN╓ filσ fo≥ áit« á SucΦ áß ì
  129. prograφ i≤ ß gooΣ candidatσ fo≥ implementatioε witΦ ß higΦ leve∞ languagσ sucΦ ì
  130. a≤ áBD╙ á┌ áo≥ áTurb∩ áPascal«  AnΣ i⌠ surσ woulΣ áhavσ áhelpeΣ ámσ áwitΦ áthσ ì
  131. experiment≤ átha⌠ á╔ áaφ áabou⌠ t∩ ádescribσ á(severa∞ ámistake≤ áresulteΣ áiε ì
  132. crashes).
  133.  
  134. M∙ Experiments
  135.  
  136.    Fig« á▒ áshow≤ ß printou⌠ oµ thσ standarΣ NZCOM.ZC═ filσ áoε ám∙ áTelevide∩ ì
  137. 803H«  I⌠ ha≤ alread∙ beeε customizeΣ iε severa∞ way≤ usinτ MKZCM«  First¼ ái⌠ ì
  138. allocate≤ ß ┤-recorΣ VBIOS«  ╔ usσ ß versioε tha⌠ fixe≤ thσ 803'≤ fau° pa≤ áoµ ì
  139. clobberinτ thσ inde° register≤ durinτ BIO╙ call≤ anΣ implement≤ ß checδ oµ thσ ì
  140. ┌-Systeφ ádrivσ vecto≥ fo≥ BIO╙ disδ-selec⌠ call≤ a≤ describeΣ iε áß ápreviou≤ ì
  141. column«  I⌠ als∩ ha≤ rooφ fo≥ ß 2░-recorΣ RCP¼ whicΦ allow≤ mσ t∩ usσ ß áful∞-ì
  142. featureΣ áRC╨ áwitΦ Carsoε Wilsoε anΣ RoΓ Friefeld'≤ residen⌠ áhistor∙ áshell¼ ì
  143. CLE─ (seσ RCPZRL11.LB╥ oε ┌-Nodes).
  144.  
  145. -----------------------------------------------------------------------------
  146.  
  147. E606 CBIOS    0080 ENVTYP    E3F4 EXPATH    0005 EXPATHS    D300 RCP
  148. 0014 RCPS    0000 IOP    0000 IOPS    DD00 FCP    0005 FCPS
  149. DF80 Z3NDIR    0023 Z3NDIRS    E400 Z3CL    00CB Z3CLS    E280 Z3ENV
  150. 0002 Z3ENVS    E200 SHSTK    0004 SHSTKS    0020 SHSIZE    E380 Z3MSG
  151. E3D0 EXTFCB    E4D0 EXTSTK    0000 QUIET    E3FF Z3WHL    0004 SPEED
  152. 0010 MAXDRV    001F MAXUSR    0001 DUOK    0000 CRT    0000 PRT
  153. 0050 COLS    0018 ROWS    0016 LINS    FFFF DRVEC    0000 SPAR1
  154. 0050 PCOL    0042 PROW    003A PLIN    0001 FORM    0000 SPAR2è0000 SPAR3    0000 SPAR4    0000 SPAR5    BB00 CCP    0010 CCPS
  155. C300 DOS    001C DOSS    D100 BIO    0000 PUBDRV    0000 PUBUSR
  156.  
  157. Figurσ á1« á Thσ ZC═ descripto≥ filσ fo≥ thσ norma∞ NZCO═ systeφ ╔ usσ áoε ám∙ ì
  158. Televide∩ 803╚ computer.
  159.  
  160. ¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡-
  161.    ╔ ádecideΣ át∩ bσ cautious¼ especiall∙ afte≥ onσ oµ m∙ ne≈ ásysteφ ádesign≤ ì
  162. causeΣ thσ systeφ t∩ hang¼ anΣ ╔ madσ ß serie≤ oµ systems¼ eacΦ differen⌠ froφ ì
  163. thσ ápreviou≤ onσ iε ß relativel∙ smal∞ way«  ╔ aφ no⌠ goinτ t∩ sho≈ áyo⌡ áal∞ ì
  164. thσ ástep≤ áalonτ thσ wa∙ bu⌠ wil∞ g∩ righ⌠ t∩ thσ ámos⌠ áradicall∙ ádifferen⌠ ì
  165. version«  Seσ Fig« 2«  Iµ yo⌡ looδ carefully¼ ╔ thinδ yo⌡ wil∞ finΣ tha⌠ áonl∙ ì
  166. thσ ácommanΣ álinσ buffe≥ (Z3CL⌐ i≤ stil∞ iε thσ samσ placσ a≤ i⌠ wa≤ áiε áthσ ì
  167. origina∞ systeφ (bu⌠ i⌠ i≤ bigge≥ now).
  168.  
  169. -----------------------------------------------------------------------------
  170.  
  171. E606 CBIOS    0080 ENVTYP    E3F4 EXPATH    0005 EXPATHS    D700 RCP
  172. 0014 RCPS    0000 IOP    0000 IOPS    D480 FCP    0005 FCPS
  173. D200 Z3NDIR    0023 Z3NDIRS    E400 Z3CL    00FB Z3CLS    E180 Z3ENV
  174. 0002 Z3ENVS    E100 SHSTK    0004 SHSTKS    0020 SHSIZE    E280 Z3MSG
  175. E2D0 EXTFCB    E300 EXTSTK    0000 QUIET    E2FF Z3WHL    0004 SPEED
  176. 0010 MAXDRV    001F MAXUSR    0001 DUOK    0000 CRT    0000 PRT
  177. 0050 COLS    0018 ROWS    0016 LINS    000F DRVEC    0000 SPAR1
  178. 0050 PCOL    0042 PROW    003A PLIN    0001 FORM    0000 SPAR2
  179. 0000 SPAR3    0000 SPAR4    0000 SPAR5    BA00 CCP    0010 CCPS
  180. C200 DOS    001C DOSS    D000 BIO    0000 PUBDRV    0000 PUBUSR
  181.  
  182. Figurσ 2«  ┴ radicall∙ reconfigureΣ NZCO═ systeφ produceΣ b∙ manuall∙ áeditinτ ì
  183. thσ ZC═ file.
  184.  
  185. -----------------------------------------------------------------------------
  186.  
  187.    Perhap≤ yo⌡ arσ wonderinτ wh∙ ╔ didn'⌠ makσ thσ mos⌠ dramatiπ demonstratioε ì
  188. possiblσ b∙ changinτ absolutel∙ ever∙ addres≤ (anΣ perhap≤ size¼ too)« á Well¼ ì
  189. therσ áwa≤ áaε extrß constrain⌠ tha⌠ ╔ wa≤ explorinτ witΦ thi≤ system« á ╔ áaφ ì
  190. runninτ áZDDOS¼ anΣ ╔ havσ specifieΣ tha⌠ thσ clocδ drive≥ bσ loadeΣ int∩ áthσ ì
  191. s∩-calleΣ áuse≥ ábuffer«  ╔ havσ eveε applieΣ thσ NZCO═ ápatcΦ á(NZCOMPAT.HEX⌐ ì
  192. tha⌠ come≤ witΦ thσ ZSDOS/ZDDO╙ packagσ s∩ tha⌠ wheε ne≈ systeφ configuration≤ ì
  193. arσ áloaded¼ áthσ clocδ drive≥ wil∞ bσ reconnecteΣ t∩ áthσ áDO╙ áautomaticall∙ ì
  194. withou⌠ thσ neeΣ fo≥ runninτ LDTI═ again.
  195.  
  196.    Iµ yo⌡ kno≈ ß lo⌠ abou⌠ ┌-System¼ yo⌡ wil∞ kno≈ tha⌠ therσ i≤ n∩ sucΦ thinτ ì
  197. a≤ áß use≥ bufferí  Thσ use≥ buffe≥ i≤ ß specia∞ creaturσ oµ NZCOM╗ i⌠ i≤ áno⌠ ì
  198. defineΣ áiε thσ ┌-Systeφ environmen⌠ descripte≥ (o≥ ¡¡ looδ closel∙ ¡¡ iε áthσ ì
  199. ZC═ file)«  How¼ then¼ doe≤ onσ determinσ wherσ thi≤ specia∞ ga≡ iε thσ memor∙ ì
  200. ma≡ oµ aε NZCO═ systeφ i≤ located┐  Tha⌠ i≤ exactl∙ wha⌠ ╔ wondereΣ myself«  ╔ ì
  201. coulΣ áhavσ ácalleΣ ZDO╙ author≤ Caφ Cotril∞ o≥ Ha∞ Bowe≥ anΣ askeΣ átheφ áho≈ ì
  202. the∙ áinfe≥ it≤ location¼ bu⌠ ╔ decideΣ t∩ experimen⌠ instead«  Wha⌠ á╔ áfounΣ ì
  203. afte≥ ávariou≤ trial≤ anΣ error≤ wa≤ tha⌠ thσ NZCO═ patcΦ seemeΣ t∩ ábσ áhapp∙ ì
  204. anΣ áablσ át∩ finΣ thσ LDTI═ clocδ modulσ s∩ lonτ a≤ thσ commanΣ álinσ ábuffe≥ ì
  205. stayeΣ áiε thσ samσ place«  Apparently¼ thσ assumptioε i≤ madσ tha⌠ áthσ áuse≥ ìèbuffe≥ ái≤ thσ memor∙ froφ 100╚ abovσ thσ star⌠ oµ thσ commanΣ linσ buffe≥ áu≡ ì
  206. t∩ thσ rea∞ CBIO╙ (E40░ t∩ E5F╞ iε m∙ case).
  207.  
  208.    ╔ ádiΣ áno⌠ perforφ exhaustivσ test≤ oµ thi≤ hypothesis«  Le⌠ u≤ ájus⌠ ása∙ ì
  209. tha⌠ ái⌠ i≤ no⌠ terribl∙ pruden⌠ t∩ tr∙ t∩ makσ usσ oµ ß 'use≥ bufferº witΦ áß ì
  210. full∙ ácustomizeΣ system«  I⌠ woulΣ bσ wise≥ t∩ desigε thσ systeφ witΦ áß ága≡ ì
  211. belo≈ thσ CBIO╙ fo≥ thσ clocδ drive≥ anΣ t∩ creatσ ß versioε oµ LDTI═ witΦ áaε ì
  212. explici⌠ áloaΣ áaddress«  Thσ NZCOMPA╘ patcΦ shoulΣ bσ omitteΣ froφ áNZCO═ áiµ ì
  213. sucΦ custoφ system≤ arσ goinτ t∩ bσ used.
  214.  
  215. A Few Bugs
  216.  
  217.    Therσ áwerσ áß áfe≈ bug≤ iε NZCO═ tha⌠ surfaceΣ durinτ áthi≤ átestinτ átha⌠ ì
  218. sugges⌠ tha⌠ NZCOM.CO═ wa≤ no⌠ quitσ designeΣ t∩ worδ rigorousl∙ anΣ t∩ handlσ ì
  219. thσ ámos⌠ ágenera∞ ásysteφ loadinτ situations«  Sometime≤ á╔ áfounΣ átha⌠ áND╥ ì
  220. module≤ ábecamσ empty¼ anΣ thσ commanΣ searcΦ patΦ wa≤ rarel∙ ápreserveΣ áwitΦ ì
  221. thesσ systems«  Codσ-containinτ modules¼ sucΦ a≤ thσ FCP¼ RCP¼ DOS¼ anΣ s∩ on¼ ì
  222. canno⌠ ábσ ámoveΣ áfroφ onσ addres≤ t∩ another« á Iµ áthei≥ ástartinτ áaddres≤ ì
  223. changes¼ áthσ ácodσ mus⌠ bσ reloadeΣ fresΦ froφ thσ ZR╠ file« á Oε áthσ áothe≥ ì
  224. hand¼ ámodule≤ tha⌠ contaiε data¼ sucΦ a≤ thσ NDR¼ shel∞ stack¼ path¼ ámessagσ ì
  225. buffer¼ áanΣ ás∩ on¼ caε anΣ shoulΣ bσ moveΣ t∩ an∙ ne≈ address¼ ás∩ álonτ áa≤ ì
  226. therσ i≤ rooφ fo≥ thσ olΣ content≤ iε thσ ne≈ home«  NZCO═ sometime≤ faileΣ t∩ ì
  227. d∩ this«  Maybσ no≈ tha⌠ ╔ havσ uncovereΣ thesσ smal∞ problems¼ ╔ caε pas≤ thσ ì
  228. informatioε áoε át∩ áJoσ Wright¼ anΣ hσ caε fi° u≡ thσ codσ át∩ áhandlσ áthesσ ì
  229. situations.
  230.  
  231. [Thi≤ articlσ wa≤ originall∙ publisheΣ iε issuσ 4│ oµ Thσ Compute≥ Journal,
  232. P.O« Bo° 12¼ SoutΦ Plainfield¼ N╩ 0708░-001▓ anΣ i≤ reproduceΣ witΦ the
  233. permissioε oµ thσ autho≥ anΣ thσ publisher« Furthe≥ reproductioε fo≥ noε-
  234. commercia∞ purpose≤ i≤ authorized« Thi≤ copyrigh⌠ noticσ mus⌠ bσ retained.
  235. (c⌐ Copyrigh⌠ 1990¼ 199▒ Socrate≤ Pres≤ anΣ respectivσ authors]
  236.