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Text File | 1993-10-25 | 7.6 KB | 163 lines

Z80MACRO.DOC 06/26 09:26.17 Documentatioε fo≥ Z80MACRO.LIB¼ ß macr∩ librar∙ createΣ ì especiall∙ fo≥ usσ witΦ thσ publiπ domaiε assemble≥ Z80MRì distributeΣ b∙ Micr∩ Cornucopia. Contributed by: Rich Brewster R.D.1 Brackney, PA 18812 (717) 663-2048 Whilσ iε graduatσ schoo∞ studyinτ philosophy¼ ╔ needeΣ ß wa∙ ì t∩ relax¼ s∩ ╔ pickeΣ u≡ ß cop∙ oµ Alaε R« Miller'≤ "Masterinτ ì CP/M"« ╔ haΣ beeε programminτ ß Sinclai≥ ZX8▒ iε machinσ codσ ì anΣ s∩ ╔ wa≤ familia≥ witΦ thσ Z80« ╔ als∩ haΣ ß chancσ t∩ ì becomσ familia≥ witΦ CP/═ iε ß previou≤ job¼ wherσ ╔ ì occasionall∙ useΣ M8░ anΣ L80« CombineΣ witΦ m∙ Kaypr∩ 4-84¼ anΣ ì thσ Z80M╥ assemble≥ froφ Micr∩ C¼ Miller'≤ booδ provideΣ aε ì interestinτ challenge. "Masterinτ CP/Mó i≤ ß successioε oµ chapter≤ involvinτ ì increasingl∙ comple° operation≤ utilizinτ CP/═ BDO╙ calls« EacΦ ì chapte≥ introduce≤ ß se⌠ oµ macro≤ t∩ adΣ t∩ ß library¼ alonτ ì witΦ somσ tes⌠ o≥ applicatioε program≤ writteε usinτ thosσ ì macros« It'≤ assumeΣ tha⌠ yo⌡ havσ Digita∞ Research'≤ MA├ ì assembler¼ o≥ Microsoft'≤ MACRO-80« Al∞ oµ thσ mnemonic≤ arσ ì 8080« S∩ ╔ haΣ t∩ translatσ int∩ Z8░ mnemonic≤ anΣ worδ withiε ì thσ limit≤ oµ Z80MR¼ whicΦ ha≤ ß fe≈ les≤ bell≤ anΣ whistles. M∙ aiφ wa≤ t∩ learε CP/M¼ assembl∙ languagσ programming¼ anΣ ì t∩ winΣ u≡ witΦ ß nicσ macr∩ library« ╔ seeφ t∩ havσ ì accomplisheΣ thosσ goals¼ anΣ a≤ ß bonu≤ I'vσ turneΣ u≡ ß fe≈ ì bug≤ iε Mr« Miller'≤ code¼ a≤ wel∞ a≤ ß buτ iε Z80MR« Oε thσ ì wholσ I'φ quitσ happ∙ witΦ Z80MR¼ bu⌠ disappointeΣ iε Miller'≤ ì book« Hσ coulΣ no⌠ havσ actuall∙ assembleΣ anΣ testeΣ al∞ oµ hi≤ ì programs¼ becausσ somσ oµ theφ d∩ no⌠ worδ a≤ the∙ stand« Still¼ ì i⌠ wa≤ ß gooΣ exercisσ fo≥ me¼ routinτ ou⌠ hi≤ errors. M∙ maiε criticisφ oµ Miller'≤ codinτ i≤ tha⌠ hσ use≤ ß lo⌠ ì oµ ver∙ genera∞ term≤ a≤ label≤ o≥ paramete≥ names¼ fo≥ instance║ ì "POINTRó anΣ "WHERE"¼ anΣ hσ i≤ no⌠ ver∙ consisten⌠ iε thσ forφ ì oµ hi≤ macros« ╔ havσ madσ thσ librar∙ a≤ structurall∙ forma∞ a≤ ì possible¼ anΣ thσ convention≤ ╔ establisheΣ arσ listeΣ below« ì I'vσ substituteΣ morσ meaningfu∞ term≤ iε man∙ cases« Miller'≤ ì format≤ arσ stil∞ followeΣ fairl∙ closel∙ fo≥ thσ mos⌠ part¼ iµ ì someonσ wishe≤ t∩ usσ thσ booδ alonτ witΦ Z80MACRO.LIB« Bu⌠ ì perhap≤ it'≤ jus⌠ a≤ wel∞ t∩ examinσ thσ librar∙ anΣ forge⌠ abou⌠ ì thσ book« I'vσ madσ s∩ man∙ improvement≤ herσ anΣ therσ tha⌠ ╔ ì can'⌠ possibl∙ documen⌠ theφ all« EacΦ subroutinσ embeddeΣ iε ß ì macr∩ ha≤ beeε optimizeΣ fo≥ thσ Z80« A≤ ß result¼ thi≤ codσ ì won'⌠ worδ oε 808░ machines. è Thσ bigges⌠ drawbacδ oµ Z80M╥ wa≤ thσ lacδ oµ ß tes⌠ fo≥ ì nul∞ parameter≤ iε macros« Iµ ß paramete≥ i≤ lef⌠ out¼ theε ì therσ i≤ simpl∙ nothinτ (ß null⌐ substituted« S∩ al∞ thσ macro≤ ì havσ mandator∙ parameters« Thi≤ requiremen⌠ resulteΣ iε thσ ì greates⌠ departurσ froφ Alaε Miller'≤ coding« ╔ spen⌠ ß lo⌠ oµ ì timσ developinτ thσ followinτ typσ oµ kludge: MACRO MULT #TWOS IF #TWOS LD B,#TWOS ENDIF ... ENDM Tha⌠ wa∙ ß ░ (zero)¼ o≥ somσ expressioε evaluatinτ t∩ zero¼ ì coulΣ servσ t∩ simulatσ ß nul∞ parameter¼ a≤ lonτ a≤ thσ valuσ ì zer∩ itselµ wa≤ no⌠ needeΣ a≤ thσ actua∞ parameter« Thi≤ seemeΣ ì likσ sucΦ ß shar≡ ideß tha⌠ ╔ haΣ man∙ oµ thσ macro≤ emplo∙ it« ì Bu⌠ theε ╔ founΣ ou⌠ tha⌠ someho≈ afte≥ Z80M╥ haΣ encountereΣ to∩ ì man∙ oµ thesσ structure≤, whicΦ combinσ ß conditiona∞ tes⌠ witΦ ß ì macr∩ parameter¼ phasσ error≤ begaε happeninτ iε grea⌠ ì proliferation« Probabl∙ ß tablσ oµ addresse≤ haΣ overflowed« ì Thσ onl∙ fi° wa≤ t∩ eliminatσ mos⌠ oµ thσ structures¼ whicΦ ╔ ì did« Somσ oµ thσ macros¼ fo≥ instancσ SYSF¼ MUL╘ anΣ EXIT¼ stil∞ ì emplo∙ it« Truσ nul∞ paramete≥ testinτ shoulΣ bσ added. Aε enhancemen⌠ tha⌠ ╔ though⌠ woulΣ bσ nicσ (althougΦ ╔ go⌠ ì b∙ O╦ withou⌠ it⌐ woulΣ bσ thσ additioε oµ logica∞ operator≤ ì (insteaΣ oµ jus⌠ thσ relationa∞ operators⌐ iε conditiona∞ ì assembly« Bu⌠ oε thσ wholσ Z80M╥ i≤ ß finσ assemble≥ anΣ ì is in complience witΦ thσ Ziloτ assemble≥ specification. --- Z80MACRO.LIB Format --- Severa∞ forma∞ rule≤ werσ followeΣ iε thσ generatioε oµ thσ ì library« Thσ firs⌠ rulσ i≤ consistenc∙ iε structure« ThougΦ thσ ì structurσ ╔ camσ u≡ witΦ ma∙ bσ idiosyncratic¼ i⌠ i≤ fairl∙ ì consisten⌠ anΣ ough⌠ t∩ bσ easil∙ graspeΣ b∙ an∙ programme≥ ì alread∙ familia≥ witΦ assembl∙ language« Thσ genera∞ structurσ ì ha≤ thσ followinτ elements: 1⌐ ┴ definitioε line, e.g. 'CPATXT MACRO #TEXT,#ADDR'. 2) A comment section describing the macro, and an example. 3⌐ Thσ main par⌠ oµ thσ macro¼ whicΦ wil∞ bσ duplicateΣ eacΦ ì time there is a reference to it in a .AZM source file. 4⌐ Aε embedded subroutinσ whicΦ i≤ flaggeΣ fo≥ conditiona∞ ì assembly so that it is only assembled once. 5⌐ Aε END═ statement¼ precedeΣ b∙ ß commen⌠ placeΣ t∩ sho≈ thσ ì end of the macro in expanded .PRN files. è Thesσ rule≤ goverε thσ usσ oµ loca∞ o≥ globa∞ labels in macros: 1) Iµ ß labe∞ i≤ founΣ iε ß globa∞ subroutine¼ i.e« onσ tha⌠ i≤ ì áááááflaggeΣ t∩ bσ assembleΣ onl∙ once¼ tha⌠ labe∞ wil∞ bσ ì áááááglobal¼ anΣ wil∞ havσ ╢ characters¼ thσ las⌠ beinτ '?'« ì áááááThi≤ yield≤ meaningfu∞ global≤ insteaΣ oµ needles≤ ì áááááassembler-generated replacements for local labels.ì Als∩ thi≤ way¼ wheε writinτ program≤ therσ i≤ n∩ neeΣ t∩ ì áááááworr∙ tha⌠ ß labe∞ iε thσ prograφ wil∞ duplicatσ onσ iε ß ì ááááámacro¼ a≤ lonτ a≤ yo⌡ remembe≥ no⌠ t∩ enΣ an∙ label≤ witΦ ß ì áááááquestioε mark« ┴ simila≥ conventioε wa≤ followeΣ fo≥ globa∞ ì ááááálabel≤ whicΦ marδ variables¼ excep⌠ thσ questioε marδ ì áááááprecede≤ insteaΣ oµ follows« Thi≤ i≤ shee≥ conventioε anΣ ì áááááma∙ bσ changeΣ iµ yo⌡ wisΦ b∙ rewritinτ thσ fe≈ occurrence≤ ì áááááiε Z80MACRO.LIB. 2) NO MACRO PARAMETERS CAN BE PLACED INSIDE A GLOBAL SUBROUTINE. Thi≤ i≤ necessar∙ t∩ kee≡ thσ macr∩ repeatable¼ whicΦ i≤ ß ì ááááágenera∞ specificatioε for al∞ macros« Tha⌠ is¼ ever∙ macr∩ ì ááááámus⌠ bσ repeatablσ withiε thσ samσ sourcσ file« Iµ ß ì áááááparamete≥ werσ placeΣ insidσ ß globa∞ subroutine¼ theε a ì áááááseconΣ referencσ oµ tha⌠ macr∩ witΦ differen⌠ parameter≤ ì áááááwoulΣ resul⌠ iε ß cal∞ t∩ thσ origina∞ subroutine¼ anΣ woulΣ ì áááááhavσ thσ origina∞ parameters. 3) Thσ #AROUN─ loca∞ labe∞ shoulΣ bσ placeΣ INSID┼ thσ ì áááááconditiona∞ assembl∙ oµ thσ subroutinσ if tha⌠ i≤ thσ onlyì áááááplacσ iε thσ macr∩ whicΦ i⌠ i≤ used« Thi≤ save≤ thσ generatioε oµ spuriou≤ loca∞ variables« Thσ ì áááááfirs⌠ pas≤ oµ thσ assemble≥ replace≤ al∞ occurrence≤ oµ ì áááááloca∞ variablσ witΦ sequentiall∙ incrementeΣ labels¼ s∩ ì ááááátherσ wil∞ bσ GAP╙ iε thσ sequencσ becausσ oµ thi≤ ì ááááátechnique« Iµ thi≤ i≤ no⌠ clear¼ jus⌠ examinσ ß .PR╬ file« ì áááááI don't think there is any serious impact to this. Thσ #AROUN─ labe∞ i≤ referenceΣ outsidσ thσ subroutinσ iε ß ì áááááfew of the macros, for instance CPATXT. Sincσ therσ arσ 2╕ flag≤ anΣ associateΣ routines¼ ╔ createΣ ì MRFLAGS.╚ a≤ ß heade≥ filσ t∩ *INCLUD┼ iε sourcσ files« Thi≤ ì wil∞ initializσ al∞ 2╕ flag≤ t∩ FALSE« Thσ crosslis⌠ iε ì MRFLAGS.DO├ wil∞ hel≡ yo⌡ determinσ wha⌠ flag≤ mus⌠ bσ ì initializeΣ iµ yo⌡ d∩ no⌠ *INCLUD┼ MRFLAGS.H. That'≤ abou⌠ ití Jus⌠ spenΣ somσ timσ studyinτ ß printou⌠ oµ ì Z80MACRO.LI┬ beforσ usinτ it« (┴ 13▓ columε printou⌠ wil∞ makσ ì the most readable listing.) Therσ arσ eigh⌠ examplσ .AZ═ file≤ ì provided¼ althougΦ the∙ d∩ no⌠ usσ al∞ oµ thσ macros« Therσ ma∙ ì stil∞ bσ ß fe≈ bugs¼ bu⌠ thosσ examplσ program≤ al∞ assemblσ anΣ ì RU╬ quitσ well« Somσ oµ theφ arσ eveε useful!