General Information on CP/M CP/M File References CP/M Line Editing and Output Control CP/M Built-In Commands CP/M Transient Commands Physical Device Assignments for ARIES-1 CP/M STAT Command CP/M PIP Command CP/M ED Command CP/M ASM Command CP/M LOAD Command The UNLOAD Command CP/M DDT Command The ZDT Command CP/M SYSGEN Command CP/M SUBMIT Command CP/M BDOS -- Basic I/O Operations CP/M BDOS -- Basic Disk Operations CP/M File Types CP/M BIOS Jump Vector :General Information on CP/M CP/Í ió á monitoò controì prograí foò microcomputeò systeí developmenô whicè  useó IBM-compatiblå flexiblå diskó (floppù disks© foò masó  storage® Usinç  á  microcomputeò  mainframå  baseä oî Intel'ó 808°  oò  Zilog'ó  Z8° microprocessor¬   CP/Í   provideó   á  generaì  environmenô   foò   prograí construction¬  storage¬  anä editing¬ alonç witè assemblù anä prograí debuç facilities®  Aî importanô featurå oæ CP/Í ió thaô iô caî bå easilù altereä tï  executå  witè anù computeò configuratioî whicè useó aî  Inteì  808°  oò Ziloç  Z8° Microprocessoò anä haó aô leasô 16Ë byteó oæ maiî memorù witè uð tï fouò IBM-compatablå diskettå drives. Thå  CP/Í monitoò provideó accesó tï programó througè á  comprehensivå filå  managemenô  system®   Thå  filå  subsysteí  supportó  á  nameä  filå structure¬  allowinç dynamiã allocatioî oæ filå spacå aó welì aó sequentiaì anä  randoí  filå access®  Usinç thió filå system¬  á uð  tï  6´  distincô programó caî bå storeä iî botè sourcå anä machine-executablå form. Digitaì  Research¬  thå  designeò oæ CP/M¬  haó provideä á seô oæ  siø manualó whicè describå thå uså anä operatioî oæ CP/Í iî detail. These manuals are: 1® Aî Introductioî tï CP/Í Featureó anä Facilities 2. ED: A Context Editor for the CP/M Disk System 3. ASM: CP/M Assembler User's Manual 4® DDTº CP/Í Dynamiã Debugginç Tooì User'ó Manual 5. CP/M Interface Guide 6. CP/M System Alteration Guide Aó thå readeò caî see¬  CP/Í supportó á contexô editor¬  aî  assembleò (Intel-compatable)¬  anä  á  debuggeò system®  Theså arå availablå iî  thå basiã CP/Í package®  Therå ió á largå varietù oæ otheò softwarå  availablå whicè  caî  ruî undeò CP/Í witè littlå oò nï modification®  Sucè  softwarå includeó  severaì  assembleró (botè 808° anä  Z80)¬  á  symboliã  debugger¬ severaì  high-leveì  languageó (includinç FORTRAΠ IÖ  {compiler}¬  BASIC-Å {translator}¬  CBASIà {translator}¬ manù interpretivå BASICs¬ ALGOL¬ FOCAL¬ anä  C)¬  anä  severaì special-purposå applicationó programó (sucè aó  texô formattinç systemó anä accountinç systems). :CP/M File References Á  filå referencå identifieó á particulaò filå oò grouð oæ fileó oî  á particulaò  disë  attacheä tï CP/M®  Theså filå referenceó caî  bå  eitheò unambiguouó  (ufn©  oò  ambiguouó (afn)®  Aî  unambiguouó  filå  referencå uniquelù identifieó á singlå file¬ whilå aî ambiguouó filå referencå maù bå satisfied by a number of different files. Aî  unambiguouó filå referencå ió aî exacô namå oæ thå specifieä file® Iô consistó oæ uð tï eighô characteró iî thå filå namå anä threå characteró in the file type. An unambiguous file reference is of the form -- pppppppp.sss Thå  characteró useä iî specifyinç aî unambiguouó filå  referencå  maù not contain any of -- < > . , ; : = ? * [ ] Aî  ambiguouó filå referencå ió useä foò directorù searcè anä  patterî matching®  Thå  forí  oæ  aî  ambiguouó filå referencå ió  similaò  tï  aî unambiguouó reference¬ excepô thå symboì '?§ maù bå intersperseä throughouô thå filå reference®  Iî variouó commandó throughouô CP/M¬  thå '?§  symboì matcheó  anù  characteò oæ á filå namå iî thå '?§ position®  Foò  example¬ X?Y.C?Í  wilì matcè XZY.COÍ anä X3Y.CEM®  Thå '*§ symboì ió useä tï  matcè alì characteró oæ á filå namå oò filå type®  Foò example¬ *.COÍ wilì matcè XZY.COM and HELP.COM, while HELP.* will match HELP.COM and HELP.HLP. :CP/M Line Editing and Output Control The following are the line editing functions supported by CP/M -- rubout Delete and echo the last character typed at the console. Ctrl-U Delete the entire line typed at the console. Ctrl-X Same as Ctrl-U. Ctrl-R Retype current command line: types a "clean line" following character deletion with rubouts. Ctrl-E Physical end of line: carriage is returned, but line is not sent until the carriage return key is depressed. Ctrl-C CP/M system reboot (warm start). Ctrl-Z End input from the console (used in PIP and ED). Other control functions affect console output -- Ctrl-P Copy all subsequent console output to the currently- assigned list device (LST:). Output is sent to both the list device and the console device until the next Ctrl-P is typed. Ctrl-S Stop the console output temporarily. Program execution and output continue when the next character is typed at the console. Typing Ctrl-C returns control to CP/M. Inpuô lineó caî generallù bå uð tï 25µ characteró iî length® Theù arå not acted upon until the carriage return key is typed. :CP/M Built-In Commands CP/M supports five built-in commands -- ERÁ  afî  -- Thå  ERÁ  (erase© commanä  removeó  fileó  froí  thå currently logged-in disk. DIÒ  afî -- Thå DIÒ (directory© commanä causeó thå nameó  oæ  alì fileó whicè satisfù thå ambiguouó filå namå afî tï bå listeä oî  thå consolå device®  Alì fileó arå listeä iæ nï afî  ió given. REΠ ufn1=ufn²  -- Thå  REÎ (rename© commanä allowó thå  useò  tï changå thå nameó oæ fileó oî disk® Thå filå satisfyinç ufn² is changed to ufn1. SAVÅ  î ufî -- Thå SAVÅ commanä placeó î pageó (256-bytå  blocks© onto disk from the TPA and names this file ufn. TYPÅ  ufî -- Thå TYPÅ commanä displayó thå contentó oæ thå  ASCIÉ sourcå  filå  ufî  oî thå currentlù logged-iî  disë  aô  thå console device. :CP/M Transient Commands The CP/M standard transient commands are -- STAÔ  Lisô thå numbeò oæ byteó oæ storagå remaininç  oî  thå currentlù    logged-iî   disk¬    providå   statisticaì informatioî  abouô  particulaò files¬  anä  displaù  oò alter device assignment. PIÐ Loaä thå Peripheraì Interchangå Prograí foò  subsequenô disk file and peripheral transfer operations. ED Load and execute the CP/M text editor program. SUBMIT Submit a file of commands for batch processing. ASÍ  Loaä  thå  CP/Í assembleò anä assemblå  thå  specifieä program from disk. LOAÄ  Loaä thå filå iî Inteì "hex¢ machinå codå  formaô  anä producå  á filå iî machinå executablå forí whicè caî bå loadeä intï thå TPÁ (thió loadeä prograí becomeó á  ne÷ command under the CCP). DDT Load the CP/M debugger into the TPA and execute it. DUMP Dump the contents of a file in hex. SYSGEN Create a new CP/M system diskette. MOVCPÍ  Regeneratå  thå  CP/Í systeí foò á  particulaò  memorù size. :Physical Device Assignments for ARIES-1 Logical Device Physical Device CON: TTY: Model 43 Teletype CRT: Hazeltine 1500 CRT BAT: CRT and Modem UC1: In=CRT, Out=CRT and Modem RDR: TTY: Model 43 Teletype PTR: Modem UR1: CRT and Modem w/CRT Output UR2: CRT and Modem PUN: TTY: Model 43 Teletype PTP: Modem UP1: CRT and Modem UP2: CRT and Modem LST: TTY: Model 43 Teletype CRT: Hazeltine 1500 CRT LPT: Modem UL1: CRT and Modem :CP/M STAT Command The STAT Command takes any of the following forms -- STAÔ Calculatå thå storagå remaininç oî alì activå driveó anä prinô  á message like x: R/W, SPACE: nnnK -- if disk is Read/Write x: R/O, SPACE: nnnK -- if disk is Read Only STAT x: Calculate the storage remaining on the specified drive and print BYTES REMAINING ON x: nnnK STAT x:afn Scaî thå specifieä fileó oî thå specifieä drivå (xº ió optional)¬ anä  lisô  alì fileó whicè satisfù thå unambiguouó  referencå  iî alphabeticaì  ordeò witè storagå requirements®  Á tablå likå thå following is generated -- RECS BYTS EX D:FILENAME.TYP rrrr nnnK ee d:pppppppp.sss where rrrr -- number of 128-byte records allocated to the file nnnK -- number of bytes (in K, K=1024) allocated to the file nnn = rrrr * 128 / 1024 ee -- number of 16K extensions ee = nnn / 16 d:pppppppp.sss -- drive name (d may be A, B, C, D) and file name STAT x:=R/O Seô thå specifieä drivå tï Reaä Only®  Thió ió cleareä bù á warí boot. When a disk is Read Only, the message BDOS ERR ON x: READ ONLY will appear if there is an attempt to write to it. STAT VAL: Displaù  thå  possiblå logicaì tï  physicaì  devicå  assignments® STAT will print the list -- CON: = TTY: CRT: BAT: UC1: RDR: = TTY: PTR: UR1: UR2: PUN: = TTY: PTP: UP1: UP2: LST: = TTY: CRT: LPT: UL1: STAT DEV: Displaù  thå  currenô logicaì tï physicaì  devicå  mapping®  Foò example, the list may appear as -- CON: = CRT: PUN: = PTP: RDR: = UR1: LST: = TTY: STAT ld1=pd1, ld2=pd2, ... Changå  thå  logicaì  tï physicaì  devicå  assignments®  Logicaì devicå ld± ió assigneä tï physicaì devicå pd1¬  etc®  Thå  valiä logical device names are -- CON: The system console device RDR: The paper tape reader device PUN: The paper tape punch device LST: The output list device The valid physical device names are -- TTY: Slow speed output device (teletype) CRT: High speed output device (cathode ray tube) BATº Batcè processinç (CONº inpuô ió RDR:¬  CONº outpuô is LST:) UC1: User-defined console PTR: Paper tape reader PTP: Paper tape punch UR1: User-defined reader #1 UR2: User-defined reader #2 UP1: User-defined punch #1 UP2: User-defined punch #2 LPT: Line printer UL1: User-defined list device #1 :CP/M PIP Command PIР (Peripheraì  Interchangå  Program© ió thå  CP/Í  transienô  whicè implementó thå basiã mediá conversioî operationó necessarù tï load¬  print¬ punch¬  copy¬  anä  combinå  disë files®  PIÐ ió initiateä bù onå  oæ  thå following forms -- PIР Engagå PIP¬  prompô thå useò witè '*'¬  anä  reaä commanä lineó directlù froí thå console® PIÐ useä iî  thió  waù ió exiteä bù eitheò typinç aî  emptù commanä linå (jusô á carriagå return© oò á  Ctrl-à as the first character of the line. PIР cmnä Engagå PIP¬  executå thå specifieä  command¬  anä return to CP/M. The form of each command line in PIP is -- destination = source#1, source#2, source#3, ..., source#n The general forms of PIP command lines are -- x:=y:afî  Copù  alì  fileó satisfyinç afî froí drivå  ù  tï drivå x®  'y§ maù bå omitted¬  and¬  iæ  so¬  thå currently logged-in drive is selected. x:ufn=yº  Copù thå filå giveî bù ufî froí ù tï x®  'x§ maù bå omitted¬  and¬  iæ so¬  thå currentlù logged-iî drive is selected. x:afn=y:afî Likå thå above¬ buô ø and/oò ù maù bå omitted» thå defaulô   drivå  ió  selecteä  foò   thå   omitteä drive(s). ld=pä  Copù  froí thå specifieä physicaì devicå  tï  thå specifieä  logicaì device®  Valiä logicaì deviceó are -- CON:, RDR:, PUN:, LST: Valid physical devices are -- TTY:, CRT:, UC1:, PTR:, PTP:, UR1:, UR2:, UP1:, UP2:, LPT:, UL1: Additional device names which may be used in PIP commands are -- NUL: Send 40 Nulls (ASCII 0) to the device. EOF: Send a CP/M End of File character (ASCII Ctrl-Z). INP: Special PIP input source to be patched (see manual). OUTº  Speciaì  PIР outpuô destinatioî tï  bå  patcheä  (seå manual). PRNº  Samå aó LST:¬  buô tabó arå expandeä aô  everù  eightè characteò position¬ lineó arå numbered¬ anä pagå ejectó are inserted every 60 lines with an initial eject. Thå  useò  caî  alsï specifù onå oò morå PIР parameteró  encloseä  iî square brackets separated by zero or more blanks. These parameters are --   Blocë modå transfer®  Datá ió buffereä bù PIÐ untiì aî ASCIÉ X- Off character (Ctrl-S) is received from the source device. Dî  Deletå characteró whicè extenä pasô columî î iî thå transfeò  oæ data to the destination from the character source. E Echo all transfer operations to the console. F Filter (remove) form feeds from the file. È Heø datá transfer® Alì datá ió checkeä foò propeò Inteì heø filå format. I Ignore ':00' records in the transfer of Intel hex format file. L Translate upper case to lower case alphabetics. N Add line numbers to each line transferred to the destination. O Object file (non-ASCII) transfer. Ignore End of File. Pn Include page ejects at every n lines. Qs^Ú Quiô  copyinç froí thå sourcå devicå oò filå wheî thå  strinç  ó (terminated by Ctrl-Z) is encountered. Ss^Z Start copying from the source file when the string s is seen. Tn Expand tabs to every nth column. U Translate lower case to upper case alphabetics. V Verify that data has been copied correctly. Z Zero the parity bit on input for each ASCII character. :CP/M ED Command Thå  EÄ  Prograí  ió thå CP/Í  systeí  contexô  editor¬  whicè  allowó creatioî anä alteratioî oæ ASCIÉ files®  Completå detailó arå giveî iî thå user's manual. The following are the error indicators given by ED -- ? Unrecognized Command > Memory buffer full # Cannot apply command the number of times specified O Cannot open LIB file in R command The following are the control characters recognized by ED -- ^C System reboot ^E Physical (not entered in command) ^I Logical tab ^L Logical in search and substitute strings ^U Line delete ^Z String terminator Rubout Character delete Break Discontinue command The following are the commands recognized by ED -- nA Append lines +/- B Beginning/Bottom of buffer +/- nC Move character positions +/- nD Delete characters E Exit nFs^Z Find string H End edit, close and reopen files Is^Z Insert characters nJ Place strings in juxtaposition +/- nK Kill (delete) lines +/- nL Move down/up lines nM Macro definition O Return to original file +/- nP Move and print pages Q Quit with no file changes R Read library file nSs1^Zs2^Z Substitute s2 for s1 +/- nT Type lines +/- U Translate lower to upper case if U; none if -U +/- V Engage/disengage line numbers (verify) 0V Print memory buffer info (free/total usage) nW Write lines nX Transfer n lines to X$$$$$$$.LIB 0X Empty X$$$$$$$.LIB nZ Sleep +/- n Move and type (+/- nLT) n: Move to absolute line (V engaged) :n Process from current line to specified line (V engaged) :CP/M ASM Command Thå ASÍ Commanä loadó anä executeó thå CP/Í 808° assembler®  Iô ió oæ the form -- ASM filename.xyz where filename ... is the name of the file 'filename.ASM' to assemble x ... designates the disk name which contains the source y ... designates the disk name to contain the hex file (y=Z suppresses generation of the hex file) z ... designates the disk name to contain the print file (y=X lists on CON:, y=Z suppresses listing) Refer to the ASM Manual for further details. :CP/M LOAD Command Thå LOAÄ Commanä readó thå filå specified¬ whicè ió assumeä tï contaiî Inteì heø formaô machinå codå anä produceó á memorù imagå filå whicè caî bå subsequently executed (converts .HEX to .COM files). It is of the form -- LOAD filename where filename is the name of the file 'filename.HEX'. :The UNLOAD Command Thå UNLOAÄ Commanä doeó thå reverså oæ thå LOAÄ Commanä -- iô convertó COM files to HEX files. It is of the form -- UNLOAD filename where filename is the name of the file 'filename.COM'. :CP/M DDT Command Thå  DDÔ  Prograí allowó dynamiã interactivå testinç anä debugginç  oæ programs generated in the CP/M environment. It is invoked by -- DDT DDT filename.HEX Š DDT filename.COM where 'filename' is the name of the program to be loaded or tested. DDT responds to the normal CP/M input line editing characters. DDT responds to the following commands -- As Perform inline assembly starting at the specified address s. D Display memory from the current address for 16 display lines. Ds Display memory from address s for 16 display lines. Ds,f Display memory from address s to address f. Fs,f,c Fill memory from start address s to final address f with byte c. G Start execution at the current value of the PC. Gs Start execution at the specified address s. Gs,â Starô executioî aô thå specifieä addresó ó anä seô á  breakpoinô at the address b. Gs,b,c Same as above with breakpoints at b and c. G,b Start execution at the current value of the PC with breakpoint b. G,b,c Same as above with breakpoints at b and c. If Insert a file name f into the default FCB. L List 12 lines of disassembled code from the current address. Ls List 12 lines from the specified address s. Ls,f List lines of disassembled code from s to f. Ms,f,d Move the block from address s to f to destination at address d. R Read file in FCB into memory at 100H. Rb Read file in FCB into memory with offset b from 100H. Ss Set (examine and alter) memory starting at address s. T Trace the next instruction. Tn Trace the next n instructions. U Untrace -- like Trace, but intermediate steps are not displayed. X Examine all registers and flags. Xr Examine specified registers or flag, where r may be -- C Carry flag Z Zero flag M Minus (sign) flag I Interdigit Carry flag A Accumulator B BC Reg pair D DE Reg pair H HL Reg pair S Stack pointer P PC :The ZDT Command ZDT is a Z80 version of DDT. It is invoked by typing -- ZDT Thå  commandó  recognizeä bù ZDÔ arå inpuô iî  single-characteò  inpuô mode®  Nï  inpuô linå editinç ió done¬  anä eacè commanä expectó aî  exacô input®  Alì bytå valueó arå exactlù twï characters¬  anä alì addresseó arå exactly four characters. The commands recognized by ZDT are -- A bbbb Enteò ASCIÉ characteró intï memorù froí keyboarä startinç aô address bbbb. B Warm Boot -- Return to CP/M. C bbbb eeee nnnn Comparå  memorù froí addresó bbbâ tï addresó eeeå  tï  blocë starting at nnnn. D bbbb eeee Dump memory from bbbb to eeee. E bbbb eeee Searcè  foò  ASCIÉ strinç froí bbbâ tï eeee®  Strinç ió  aô most 16 characters. String is terminated by . F bbbb eeee Searcè  foò  heø  strinç  froí  bbbâ  tï  eeee®  Strinç  ió terminated by . G Go to next breakpoint. H aaaa nnnn Hex add and subtract. Computes aaaa+nnnn and aaaa-nnnn. I nn Input. Prints value at port nn. J nnnn Jump to and execute at location nnnn. K Keyboard echo. L filename.typ nnnn Loads specified disk file into location nnnn. M bbbb eeee nnnn Move block from bbbb to eeee-1 to nnnn. N aaaa Enter offset aaaa for loading. O nn dd Output byte dd to port nn. P bbbb Inpuô heø intï memorù froí keyboarä startinç aô bbbb®  or backs pointer. Q bbbb eeee Dumps from bbbb to eeee in ASCII. R n ll tt ss bbbb Reaä blocë oæ datá froí disë î oæ lengtè lì (256-bytå pages© starting at track tt and sector ss placing the data at bbbb. S bbbb eeee Disassembly (symbolic dump) from bbbb to eeee. T bbbb eeee Destructive memory test from bbbb to eeee-1. U bbbb Set breakpoint at bbbb. V Display all currently-set breakpoints. W n ll tt ss bbbb Writå oî disë î thå datá aô bbbâ foò á lengtè oæ lì startinç at track tt, sector ss. ll is in 256-byte pages. X Display registers. Z bbbb eeee dd Zero or set memory from bbbb to eeee-1 with byte dd. :CP/M SYSGEN Command Thå  SYSGEÎ transienô commanä allowó generatioî oæ aî initializeä disë containing the CP/M Operating System. It is invoked by typing SYSGEN Oncå invoked¬  thå useò ió prompteä througè thå session® Refeò tï thå CP/M Manual for further details. :CP/M SUBMIT Command Thå  SUBMIÔ  commanä allowó CP/Í commandó tï bå batcheä  togetheò  foò automatic processing. The form of this command is SUBMIT ufn parm1 parm2 ... parmn Thå ufî giveî iî thå SUBMIÔ commanä musô bå thå filenamå (noô type© oæ á  filå whicè existó oî thå currentlù logged-iî disë witè aî  assumeä  filå type of '.SUB'. Refer to the CP/M Manual for further details. :CP/M BDOS -- Basic I/O Operations Function and Number Input Parameters Output Parameters Read Console 1 None ASCII Char in A Write Console 2 ASCII Char in E None Read Reader 3 None ASCII Char in A Write Punch 4 ASCII Char in E None Write List 5 ASCII Char in E None Get I/O Status 7 None I/O Status in A Put I/O Status 8 I/O Status in E None Print Buffer 9 Address of string None terminated by $ in DE Read Buffer 10 Address of Read Read Buffer is filled Buffer in DE Console Ready 11 None LSB of A is 1 if char ready *All function numbers are passed in Reg C. I/O Status Byte -- Value Bits 6&7 Bits 4&5 Bits 2&3 Bits 0&1 00 CON:=TTY: RDR:=TTY: PUN:=TTY: LST:=TTY: 01 CRT: PTR: PTP: CRT: 10 BAT: UR1: UP1: LPT: 11 UC1: UR2: UP2: UL1: Read Buffer -- Byte Function 1 Maximum Buffer Length 2 Current Buffer Length (returned value) 3-n Data (returned values) :CP/M BIOS -- Basic Disk Operations Function and Number Input Parameters Output Parameters Lift Head 12 None None Init BDOS 13 None None Log-In Disk 14 Value in Reg E None A=0, B=1, C=2, D=3 Open File 15 Address of FCB Byte address of FCB in DE if found or 0FFH if not Close File 16 Address of FCB Byte address of FCB in DE if found or 0FFH if not Search for File 17 Address of FCB Byte address of first FCB in DE if found or 0FFH if not Search for Next 18 Address of FCB Byte address of next FCB in DE if found or 0FFH if not Delete File 19 Address of FCB None in DE Function and Number Input Parameters Output Parameters Read Next Record 20 Address of FCB 0=successful read in DE 1=read past EOF 2=reading random data Write Next Rec 21 Address of FCB 0=successful write in DE 1=error in extending 2=end of disk data 255=no more dir space Make File 22 Address of FCB Byte address of FCB or in DE 255 if no more dir space Rename FCB 23 Address of FCB Byte Address of Dir entry in DE or 255 if no match Read Drive No 25 None Number of logged-in drive (A=0, B=1, C=2, D=3) Set DMA Address 26 Address of 128 None byte buffer in DE *All function numbers are passed in Reg C :CP/M File Types ALG ALGOL 60 Source File ASM Assembler Source File BAK Backup File BAS BASIC Source File (CBASIC) C C Source File COM "Command" File (Binary ORGed to 100H) FOR FORTRAN IV Source File HEX Intel "hex" code file HLP HELP File INT BASIC Intermediate File LST Listing File MAC MACRO-80 Source File PRN Assembler Listing File SRC PASCAL/MT Source File SUB SUBMIT File TC Tiny-C Source File TFS TFS Source File TXT Text File $$$ Temporary File :CP/M BIOS Jump Vector Thå  followinç ió á tablå representinç thå entrù pointó intï thå  CP/Í BIOS of the major routines accessable to the user -- Routine Relative Offset Comment BOOT 00H Cold Start WBOOT 03H Warm Start CONST 06H Console Status Reg A = 00 if no char ready Reg A = FF if char ready Š CONIN 09H Console char in (Reg A) CONOUT 0CH Console char out (Reg C) LIST 0FH List out (Reg C) PUNCH 12H Punch out (Reg C) READER 15H Reader in (Reg A) Routine Relative Offset Comment HOME 18H Move to track 00 SELDSK 1BH Select disk given by Reg C (A=0,B=1,...) SETTRË  1EÈ  Seô  tracë  addresó  giveî  bù  Reç  Ã (0...76) SETSEà 21È  Seô  sectoò  addresó giveî  bù  Reç  Ã (1...26) SETDMA 24H Set subsequent DMA address (RP B&C) READ 27H Read track/sector (block) WRITE 2AH Write track/sector (block)