;****************************************************** ; North Star Disk Exerciser for CP/M, Version 1.02 ; (Single Density Controller) ; ; Commands: ; ; BO Boots from disk ; LH Load head and keep it loaded, with ; option to nudge the head either way ; MS Measure spindle revolution time ; RE Restore to track 0 ; RS S AAAA Read sector S into memory at ; address AAAA ; SK [TT] Seek track TT ; SU [U] Set disk unit (1-3) ; WS S AAAA Write sector S from memory at ; address AAAA ; ? brief help screen ; ;****************************************************** ; Notes ; ; Nudging: ; The SA400 drive exhibits 'gear lash' in its head ; positioner - the head will be off-track slightly ; toward the outside diameter when a track is ; approached from the outside (stepping toward a higher ; track), and will be off-track slightly toward the ; inside diameter when a track is approached from the ; inside (stepping toward a lower track). The nudge ; sub-commands of the LH function (+ and -) allow you ; to approach the alignment track from either ; direction to observe this difference. ; ; Use the LH function to keep the head loaded during ; radial alignment (Section 2.4.18 in the SA400 ; Service Manual). Nudge the head in both directions ; while performing the alignment, and balance the ; alignment between the two directions. ; ; Spindle Rotation measurement: ; The MS command first measures the CPU speed by ; measuring the time for the Northstar controller ; to generate 125 fake sector pulses while no drive ; is selected. It then uses this measured CPU speed ; to measure the time for 50 actual sector pulses ; (5 disk revolutions). This assumes NODEXER is running ; in zero waitstate RAM.Use this function to adjust ; the drive's spindle rotation speed to be ; 200 mS/revolution. Allow the spindle motor drive to ; warm up for a few minutes before adjusting, as it ; will speed up by about 1% as it warms up. ;****************************************************** ; Revision History ; 1.00 19 November 2014 M. Eberhard ; Created ; ; 1.01 10 October 2015 M. Douglas ; - Fix LH (Load Head command) which previously unloaded ; immediately after loading the head. ; ; 1.02 05 November 2015 M. Douglas ; - Fix problem that caused one character commands (e.g.,"?") ; to not always work. The command failed to execute if ; the third byte in the input buffer didn't happen to ; be zero or a valid ASCII decimal value was present. ; ; - Verify both a sector and address are specified for the read ; and write sector commands, otherwise the program crashed. ; ; - If no parameter is specified for seek track (SK) or set ; disk unit (SU), the commands now display the current ; track or unit number. ; ; - Update the LH command to use "H" to toggle head load ; (drive select) in addition to space bar. Add the "M" ; command to toggle motor on/off (on does a drive select, ; off does de-select & motor off). Display a message on ; each change of state to indicate what was done. ; ; - Accept upper or lower case letters. ; ; - Display only the banner and help instructions at ; power up to avoid scrolling off a 16 line screen. ; ; - Change error message to "huh?" ; ; To Do (maybe) ; initialize disk command ; fast-copy disk command with aggressive recovery ;****************************************************** FALSE equ 0 TRUE equ not FALSE ;************* ; CP/M Equates ;************* ;------------------------------------------ ;BDOS Entry Points and low-memory locations ;------------------------------------------ WBOOT equ 0000H ;Jump to BIOS warm boot WBOOTA equ WBOOT+1 ;Address of Warm Boot BDOS equ WBOOT+5 ;BDOS Entry Point COMBUF equ WBOOT+80H ;disk & cmd line buffer USAREA equ WBOOT+100H ;User program area LINBUF equ COMBUF ;use CP/M's buffer for input LBSIZE equ 64 ;max input line (huge) ;------------------------------------------ ;BDOS Function Codes, passed in register C ;------------------------------------------ ;BRESET equ 0 ;System Reset ;BCONIN equ 1 ;Read Console Chr ;BCONOT equ 2 ;Type Chr on Console ;BPRINT equ 9 ;Print $-terminated String BRDCON equ 10 ;Get Line from Console ;BCONST equ 11 ;Console Status (<>0 IF CHR) ;BDRST equ 13 ;Reset Disk ;BSDISK equ 14 ;select disk ;BOPEN equ 15 ;Disk File Open ;BCLOSE equ 16 ;Close disk file, FCB at de ;BSERCH equ 17 ;Search dir for file, FCB at de ;BDELET equ 19 ;delete file, FCB at (de) ;BREAD equ 20 ;Read from Disk, 0=OK, <>0=EOF ;BWRITE equ 21 ;Write next record, 0=OK, <>0=ERR ;BMAKE equ 22 ;Make new file, 0FFH=BAD ;BCDISK equ 25 ;get current disk ;BSTDMA equ 26 ;Set disk buffer to (de) ;-------------------------------------------------------- ;BIOS Entry Points, relative to the base address in WBOOT ;-------------------------------------------------------- CONST equ 06h ;Console Status CONIN equ 09h ;Console Input CONOUT equ 0Ch ;Console output ;************************************************ ; Northstar disk Controller Addresses & Commands ; (Read or write from address to execute command) ;************************************************ NSCTRL equ 0E800h ;Northstar disk controller NSBOOT equ NSCTRL+100h ;disk boot PROM NWRITE equ NSCTRL+200h ;write prefix (data in low byte) NCOMND equ NSCTRL+300h ;commands NASTAT equ NCOMND+10h ;read A status NBSTAT equ NCOMND+30h ;read B status NSTRST equ NCOMND+09h ;set track step flip flop NCTRST equ NCOMND+08h ;clear track step flip flop NSTOUT equ NCOMND+1Ch ;set step direction to 'out' NSTIN equ NCOMND+1Dh ;set step direction to 'in' NMOTRA equ NCOMND+90h ;motor on, read A stat NRBYTE equ NCOMND+50h ;read a byte of data NWRCRD equ NCOMND+04h ;start write record sequence NRSEFL equ NCOMND+14h ;reset sector flag NRESET equ NCOMND+18h ;reset controller ;**************************** ; Disk Controller Status Bits ;**************************** NSTR0 equ 1 ;NASTAT: track 0 NSWP equ 2 ;NASTAT: write protect NSBDY equ 4 ;NASTAT: body (sync chr found) NSWRT equ 8 ;NASTAT: write ready NSSP equ 0Fh ;NBSTAT: sector position NSMO equ 10h ;NASTAT & NBSTAT: motor on NSWN equ 40h ;NASTAT & NBSTAT: window flag NSSF equ 80h ;NASTAT & NBSTAT: sector flag ;************************** ; Disk Controller constants ;************************** SYNC equ 0FBh ;header sync charactor WRMUP equ 32h ;warm up time in sectors SETL equ 0Dh ;head settling time in sectors SWAIT equ 08Ch ;max wait for body before error MAXUNT equ 3 ;max disk drive unit (0 not allowed) MAXTRK equ 39 ;max track (SA400L) MAXSEC equ 9 ;max sector (SA400 and SA400L) ;************** ; ASCII equates ;************** CR equ 0Dh ;carriage return LF equ 0Ah ;line feed ;****************** ; Program Constants ;****************** DPRMPT equ '+' ;Disk test prompt MAXINP equ 64 ;Longest allowed user input ;============================================= ; Initialization ;============================================= org USAREA di lxi sp,STACK ;local stack lxi h,01FFh ;initialize CRTRAK & CRUNIT shld CRTRAK call CILPRT db 'North Star Single Density Disk Exerciser Vers. 1.02',CR,LF db ' by Martin Eberhard',CR,LF,LF db 'Type ? for help',CR,LF+80h jmp CPROC ;start main loop ;********************************** ; Disk Test Subsystem Command Table ;********************************** NSTAB: db 'BO' ;Boot dw ASKBOT db 'LH' ;load head dw LHCMD db 'MS' ;measure spindle speed dw NSMSPD db 'RE' ;restore dw NSRSTR db 'RS' ;read sector dw NSREAD db 'SK' ;seek track dw NSSEEK db 'SU' ;select unit dw NSUNIT db 'WS' ;write sector dw NSWRIT db '?',0 ;help dw NSHELP db 0 ;table end ;******============================ ;* ? * Help ;****** ;================================== NSHELP: call CILPRT db 'BO Boot from A:',CR,LF db 'LH Load/unload head (drive select/deselect)',CR,LF db 'MS Measure spindle rotation',CR,LF db 'RE Restore',CR,LF db 'SK [tt] Seek track tt (0-39)',CR,LF db 'SU [u] Select unit u (1-3)',CR,LF db 'RS s aaaa Read sector s (0-9) into RAM at address aaaa',CR,LF db 'WS s aaaa Write sector s (0-9) from RAM at address aaaa',CR,LF db LF,'Addresses are hex, all others are decimal.',CR,LF+80h ; 123456789012345678901234567890123456789012345678901234567890 ret ;================================ ;Command Processor for Subsystems ;================================ ;******************* ;bogus command input ;******************* BADINP: call CILPRT db 'huh','?'+80h ; Fall into CPROC ;************************************************* ; Command Processor Main Entry ; Gets and process commands from the user ; On Entry: ; COMTAB = address of command table, ; which preceeds the execution routines ; first table byte = current prompt character ;************************************************* CPROC: lxi sp,STACK ;repair stack call CILPRT ;print prompt db DPRMPT+80h lxi d,CPROC ;create return address push d ;..on the stack ;Get a line of input from the user call GETLIN rz ;No command? no error. ;Look for and execute the command if found lxi h,NSTAB-1 ;command table xchg ;command to hl ;..table to de ;Search through table at de for a 2-chr match of (hl) NXTCOM: inx d ;skip over address high byte ldax d ora a ;table end? jz BADINP ;y: unknown command xra m ;test first chr mov b,a ;temp save result inx d ;2nd table chr ldax d inx h ;2nd input chr xra m ;test 2nd chr inx d ;point to address low byte inx d ;point to address high byte dcx h ;back to 1st input chr ora b ;both chrs match? jnz NXTCOM ;NO match: keep looking ;Got a match. Get routine address and put it on stack xchg ;(hl)=routine address high byte ;de= input pointer mov b,m ;get routine address from table dcx h mov c,m ;bc=routine address push b ;command address on stack inx d ;skip past 2-letter command inx d ;Get the following parameter (if any) and put it in hl. ;Set the Z flag if no parameter is present. ;Leave de pointing to the 1st chr after the 1st parameter. ;'return' to the command routine on the stack. ; fall into GETDEC ;***Subroutine************************************** ; Skip spaces, then convert ASCII decimal digits in ; input buffer to binary. Stop when a space or the ; end is encountered. Bad decimal aborts via BADINP. ; On Entry: ; Input string starts at (de) ; On Exit: ; Z set if no value found ; abort to BADINP for bogus decimal or value>99 ; b=value, default = 0 ; de advanced past chr ; trashes c ;*************************************************** GETDEC: mvi b,0 ;initial value call SKIPB ;skip blanks rz ;no input: Z set GDLOOP: ldax d ;get character ora a ;end of line? jz GH1 ;Y: done cpi ' ' ;end of parameter? jz GH1 sui '0' ;un-ascii cpi 10 ;valid? jnc BADINP mov c,a ;temp save new digit mov a,b ;multiply by 10 cpi 10 ;will next digit overflow? jnc BADINP ;too big? add a ;x2 add a ;x4 add b ;x5 add a ;x10 add c ;combine digits mov b,a ;save partial result inx d ;bump the pointer jmp GDLOOP ;get more digits ;***Subroutine************************************** ; Skip spaces, then convert ASCII hex digits in ; input buffer to binary. Stop when a space or the ; end is encountered. Bad hex aborts through BADINP. ; On Entry: ; Input string starts at (de) ; On Exit: ; Z set if no value found ; abort to BADINP for bogus hex ; hl=value, default = 0 ; de advanced past chr ; trashes a,c ;*************************************************** GETHEX: lxi h,0 ;default value call SKIPB ;skip blanks rz ;no input: Z set GHEXLP: ldax d ;get character ora a ;end of line? jz GH1 ;Y: done cpi ' ' ;value separator? jz GH1 ;Y: done dad h ;make room for the new one dad h dad h dad h call HEXCON ;do the conversion jc BADINP ;bogus hex: error add l mov l,a ;move it in inx d ;bump the pointer jmp GHEXLP GH1: inr a ;good value: clear Z flag ret ;***Subroutine************************* ; Convert ASCII hex digit to binary ; On Entry: ; a=chr to convert ; On Exit: ; a=binary ; carry clear if OK, set if bogus chr ;************************************** HEXCON: sui '0' ;remove ASCII bias cpi 10 cmc ;so carry means error rnc ;IF 0-9 then we're done sui 'A'-'9'-1 ;subtract gap to ASCII A cpi 10 ;netween ASCII 9 and A? rc ;error:return w/ carry cpi 10h ;above ASCII F? cmc ;so carry means error ret ;return with or w/o carry ;***Subroutine*********************************** ; Get a line of input from the user ; Scan past blank positions looking for the first ; non-blank character. This assumes that LINBUF ; fits fully within one page of RAM. ; On Exit: ; Z set, carry clear if none found ; a=1st character value if found ; carry set if chr is below ' ' ; de = address of 1st non-blank chr ;*********************************************** GETLIN: mvi c,BRDCON ;get user input lxi d,LINBUF ;give CP/M a buffer push d mvi a,LBSIZE ;buffer size stax d call BDOS ;get input line pop d ;de->LINBUF inx d ;de->byte count (from BDOS call) ldax d ;a=byte count mov c,a ;c=byte count inx d ;de->start of input characters push d ;stack has pointer to start of data GLLOOP: ldax d ;a=next character from buffer cpi 'A' ;alpha? jc GLSKIP ;no, skip it ani 5fh ;convert to upper case stax d GLSKIP: inx d ;de->next character position dcr c ;decrement buffer length count jnz GLLOOP ;Store two trailing null characters xra a stax d ;paste in terminating null inx d stax d ;2nd null in case one char command ;Skip leading blanks, and set Z for blank lines pop d ;Beginning of user input ;Fall into SKIPB ;***Subroutine*********************************** ; Scan past blank positions looking for the first ; non-blank character. ; On Entry: ; de = address of next input buffer chr ; On Exit: ; Z set, carry clear if none found ; a=1st character value if found ; carry set if chr is below ' ' ;*********************************************** SKIPB: ldax d ;get next character ora a ;end of line? rz cpi ' ' rnz ;we are past blanks inx d ;next scan address jmp SKIPB ;keep skipping ;***Subroutine******* ; Print CR, LF ; Trashes psw ;******************** PCRLF: call ILPRNT db CR,LF+80H ret ;***Subroutine***************************************** ; Print CR, LF, then In-line Message ; The call to ILPRNT is followed by a message string. ; The last message chr has its msb set. ; Trashes psw ;****************************************************** CILPRT: call PCRLF ;Fall into ILPRNT ;***Subroutine***************************************** ; Print In-line Message ; The call to ILPRNT is followed by a message string. ; The last message chr has its msb set. ; On Exit: ; Z cleared ; Trashes psw ;****************************************************** ILPRNT: xthl ;Save hl, get msg addr push b IPLOOP: mov a,m ani 7Fh ;strip end marker mov c,a call PRINTC ;print byte mov a,m ;end? inx h ;Next byte ora a ;msb set? jp IPLOOP ;Do all bytes of msg pop b xthl ;Restore hl, ;..get return address ret ;******================================== ;* BO * Boot from Northstar Disk after ;****** Asking the user to insert a disk ;======================================== ASKBOT: call CILPRT db 'Boot drive A (Y/N)','?'+80h call GETLIN cpi 'N' ;abort? jz CPROC ;y: go to command cpi 'Y' jz NSBOOT ;boot from disk jmp ASKBOT ;******================================================= ;* LH * Load Head and Keep it Loaded. ;****** 'H' or space toggles head load (drive select) ; 'M' toggles motor on/off ; '+' nudges in then out ; '-' nudges out then in ; 'Q' quits ;======================================================= LHCMD: call CILPRT db 'H toggles head load (drive select)',CR,LF db 'M toggles motor on/off (drive select & motor)',CR,LF db '+ nudges in then out',CR,LF db '- nudges out then in',CR,LF db 'Q quits',CR,LF+80h LHSLCT: mvi d,0 ;start with drive selected call CILPRT db 'SELECTED (head loaded, motor started)',' '+80h LHLOOP: mov a,d rrc cc UNSLCT cnc NSELCT call TESTQ ;Anything from kbd? push d ;save de lxi d,NSTIN cpi '+' ;approach from the OD? cz HNUDGE dcr e ;de=NSTOUT cpi '-' ;approach from the ID? cz HNUDGE pop d ;restore de cpi 'M' ;motor off? jnz LHCHKH ;no, go check for H command mov a,d ;test current select state rrc jc LHSLCT ;presently de-selected, go select inr d ;change to de-selected state lda NRESET ;reset deselects and turns off motor call CILPRT db 'DE-SELECTED (head unloaded, motor off)',' '+80h jmp LHLOOP LHCHKH: cpi 'H' ;toggle head state? jz LHTGLH ;yes cpi ' ' ;accept space too jnz LHLOOP LHTGLH: mov a,d ;test current select state rrc jc LHSLCT ;presently de-selected, go select inr d ;change to de-selected state call CILPRT db 'DE-SELECTED (head unloaded)',' '+80h jmp LHLOOP ;---Local Subroutine-------------- ; Nudge the head one track ; On Entry: ; de = NSTIN or NSTOUT ; Returns with a=0 or 2 ; trashes psw,de,h ;--------------------------------- HNUDGE: mvi h,1 ;1 step call NSSTEP mvi h,1 ;1 step again mov a,e xra h ;switch direction mov e,a jmp NSSTEP ;---Local Subroutine-------------- ; Deselect drive ; trashes a, does not change carry ;--------------------------------- UNSLCT: lda NCOMND ;Y: deselect drive to ret ;..unload its head ;******============================= ;* MS * Measure and report spindle ;****** revolution time in mSec ;=================================== NSMSPD: ;---------------------------------------------------- ;Measure CPU speed by comparing to the Northstar disk ;controller's clock. (The N* contoller will generate ;32.768 mS "sector" pulses when no drive is selected. ; (1000 * 2^16/2,000,000hz = 32.768 mS) ;---------------------------------------------------- call CILPRT db 'Measuring CPU Speed:',' '+80h lda NCOMND ;select no drive mvi a,125 ;time 125 "sectors" call TIMSEC ;Divide result in (b,hl) by 8 to get CPU speed in 102.4 Hz units mvi c,3 DIV8LP: xra a ;clear carry mov a,b rar mov b,a mov a,h rar mov h,a mov a,l rar mov l,a dcr c jnz DIV8LP mov a,b ;result too big? ora a jnz TOOBIG ;y: error, exit lxi d,-10240 ;print CPU speed and divide ;result by 1024 while doing ;..decimal conversion mvi a,4 ;4 digits after the decimal call DIVIDE ;result lands in QOTENT call ILPRNT db ' MHz',' '+80h ;Detect and report type of CPU sub a ;test for 8080 or Z80 cpe IS8080 cpo ISZ80 call ILPRNT db '80 CPU detecte','d'+80h ;Compute hl= -(cpu speed) for rev-timing math lhld QOTENT ;binary CPU speed mov a,h ;compute -(CPU speed) cma mov h,a mov a,l cma mov l,a inx h ;complement and add 1 ;------------------------------------------------ ;Measure the spindle speed by counting cycles and ;dividing by the measured CPU speed. Do this over ;and over until the user types Q. ; hl = -(CPU speed) ;------------------------------------------------ push h ;-(cpu speed) onto stack call NSELCT ;load the head call CILPRT db 'Measuring spindle revolutions. Q to quit.',CR,LF+80h MSLOOP: mvi a,50 ;50 sectors to time call TIMSEC ;time 50 sectors ;..result in (b,hl) ;(b,hl) = cycle count for 50 sectors mov a,b ani 0FEh ;17 bits max jnz TOOSLO ;Time (uS/rev) = ((b,hl)*10) / (CPU speed) pop d ;de= -(CPU speed) push d ;save for next pass mvi a,2 ;2 digits after decimal pt call DIVIDE ;divide (b,hl) by CPU speed ;..print result in mS call ILPRNT db ' mSec/rev',CR,LF+80h ;Keep measuring until the user types Q MSLP2: call TESTQ jmp MSLOOP ;Error: CPU speed is too high TOOBIG: call ILPRNT db 'out of rang','e'+80h ret ;Error: spindle is too slow TOOSLO: call CILPRT db 'Spinde too slo','w'+80h jmp MSLP2 ;---Local Subroutine----------- ;Print 1st part of 8080 message ; On Exit: ; Parity is even ;------------------------------ IS8080: call ILPRNT db '8','0'+80h sub a ;set parity even again ret ;---Local Subroutine----------- ;Print 1st part of Z80 message ;------------------------------ ISZ80: call ILPRNT db 'Z'+80h ret ;******============================ ;* RE * Restore Disk to Track 0 ;****** ; On Exit: ; a=track=0 ;================================== NSRSTR: call NSELCT ;select drive, spin up ;Step in once, in case the head is lost lxi d,NSTIN ;step in once mvi h,1 call NSSTEP ;step in now jz STUCK0 ;z: Stuck on track 0 ;Step out enough times that we should find track 0 even ;if the SA400's actuator is out of its spiral groove mvi h,MAXTRK+16 ;more than enough dcr e ;e=NSTOUT to step out call NSSTEP ;steppin' out to track 0 rz ;z set: found track 0 ;Error: track 0 not detected despite many steps outward call CILPRT ;can't find track 0 db 'No track ','0'+80h jmp CPROC ;repair stack & quit ;******============================== ;* RS * Read Sector (0-9) ;****** ; On Entry: ; b = desired sector number ; (de) = Memory address ;==================================== NSREAD: jz BADINP ;no parameter specified call NSETUP ;set up for read/write ;Wait for sector body mvi b,SWAIT ;max time until body NSRD1: dcr b ;(5) jz NOSYNC ;(10)no sync character lda NASTAT ;(13)look for sync chr ani NSBDY ;(7) jz NSRD1 ;(10)keep looking lxi b,0 ;initial CRC, 256 bytes ;Read sector data NSRD2: lda NRBYTE ;read a byte mov m,a ;save it xra b ;compute checksum rlc mov b,a inx h ;bump pointers dcr c ;256 byteS jnz NSRD2 ;Check CRC lda NRBYTE ;get disk CRC xra b ;compare to computed CRC rz ;Z flag set if OK, else error call CILPRT db 'CRC erro','r'+80h ret ;******=============================== ;* SU * Set Unit (1-3) ;****** ; On Entry: ; b = desired unit ; On Exit: ; CRUNIT = desired unit ; CRTRAK < 0, since we don't Know ; Where we are anymore ;===================================== NSUNIT: jnz SUSET ;unit parameter is present call CILPRT db 'Current unit is',' '+80h lda CRUNIT ;display current unit number mov b,a jmp DSPDEC SUSET: mov a,b dcr a ;only 1-3 allowed cpi MAXUNT jnc BADINP inr a ;1-3 sta CRUNIT ;remember new unit cma ;sets msb sta CRTRAK ;don't know where we are ret ;ret WITH Z clear ;******============================== ;* WS * Write Sector (0-9) ;****** ; On Entry: ; b = desired sector number ; (de) = Memory address ;==================================== NSWRIT: jz BADINP ;no parameter specified lda NASTAT ;check for write protect ani NSWP jnz WPERR call NSETUP ;set up for read/write ;Wait for controller to be ready to write the sector lda NWRCRD ;prepare to write NSWR1: lda NASTAT ;wait for controller ani NSWRT ;..to get ready to write. jz NSWR1 ;Write sector header lxi b,NWRITE ;C=0,b=write prefix lxi d,000FH ;number of header zeros, ;init CRC calculation NSWR2: ldax b ;write now. dcr e ;count header zeros jnz NSWR2 ;Write sector sync character mvi c,SYNC ;write sync chr ldax b ;Write sector data NSWR3: mov c,m ;get chr from RAM mov a,c ;Calculate CRC xra d ;keep CRC in d rlc mov d,a ldax b ;write chr to disk inx h ;bump pointers dcr e ;write 256 bytes jnz NSWR3 ;Write sector CRC mov c,d ;Write CRC to disk ldax b ret ;don't wait for end of sector ;..since user is slow ;******============================ ;* SK * Seek Track (0-39 decimal) ;****** (Supports also SA400L) ; On Entry: ; b= desired track ;================================== NSSEEK: jnz SKTRAK ;track param present, do seek call CILPRT db 'On track',' '+80h lda CRTRAK ;a=current track number ora a jm SKNOTK ;msb set=track undefined mov b,a ;otherwise, display track number jmp DSPDEC SKNOTK: call ILPRNT db 'unknow','n'+80h ret SKTRAK: mov a,b cpi MAXTRK+1 jnc BADINP ;bogus? mov l,a ;save track number call NSELCT ;select drive, spin up lda CRTRAK ;where are we? ora a ;0FFh means we don't know cm NSRSTR ;lost: restore ;Compute the required number of steps and the direction sub l ;which way to step? rz ;already there? lxi d,NSTOUT ;desiredcurrent NSSK1: ;Remember target track, and step there mov h,a ;number of steps mov a,l ;remember target track sta CRTRAK ;..is new track, when done ;Fall into NSSTEP ;***Subroutine******************************* ; Step Head ; On Entry: ; h = number of steps, >0 ; de = step command: NSTIN or NSTOUT ; On Exit: ; Z set, a=0, and CRTRAK=0 if track 0 found ; a = 2 otherwise ; trashes psw,bc, h ;******************************************** NSSTEP: ldax d ;set step direction NSSTP1: lda NSTRST ;Reset step flipflop xthl ;(18)must be here for delay. xthl ;(18)at least 10 uSec mvi b,2 ;(7)step timer lda NCTRST ;set step flipflop call NSWAIT ;wait 2 sector times lda NASTAT ;at track 0? rar ;NSTR0 is bit 0 jc NSSTP2 ;y: stop stepping dcr h ;n: step again jnz NSSTP1 ;stepped enough? inr h ;clear Z: not track 0 ret ;On track 0. clear CRTRAK, and return with Z set NSSTP2: xra a ;set Z: track 0 sta CRTRAK ret ;***Subroutine****************************** ; Set up read or write, then wait for sector ; On Entry: ; b = desired sector number ; (de) = target memory address ; On Exit: ; hl = memory address ; Z cleared if an error occured ; trashes psw,bc,de ;******************************************* NSETUP: mvi a,MAXSEC ;legal sector? cmp b ;n: set carry jc BADINP ;bad sector number push b ;save b=sector call GETHEX ;get hl=memory address jz BADINP ;address not present call NSELCT ;select drive, spin up pop d ;recover d=desired sector ;Wait for desired sector, following a sector pulse NSRWS1: mvi b,1 call NSWAIT ;wait for next sector pulse lda NBSTAT ;get current sector number ani NSSP ;just the sector number bits cmp d ;is this the sector we want? rz ;y: return quickly jmp NSRWS1 ;n: wait for next sector ;***Subroutine******************************** ; Turn on the motor if necessary, Select drive ; On Entry: ; CRUNIT = desired drive (1-3) ; trashes psw,bc ;********************************************* NSELCT: mvi b,WRMUP-SETL ;motor warmup time ;Long delay if motors are off lda NMOTRA ;turn on drive motors ani NSMO ;were they already on? cz NSWAIT ;n: spin them up ;Select drive, load head mvi b,NCOMND/256 ;select drive lda CRUNIT mov c,a ldax b ;Load head on drive c ;Wait for settling time after head load mvi b,SETL ;head settling time ;Fall into NSWAIT to stall ;***Subroutine*********************** ; Wait for b sectors ; On Entry: ; b = number of sectors to wait for ; trashes psw,b ;************************************ NSWAIT: lda NRSEFL ;reset sector flag NSWAT1: lda NMOTRA ;get a status, bump motor ora a ;test NSSF: sector hole? jp NSWAT1 ;nope. dcr b ;wait for b sectors to pass rz jmp NSWAIT ;***Subroutine************************************** ; Time sectors ; On Entry: ; a = number of sectors to time ; On Exit: ; b,hl = total number of passes ; where each pass is 50 CPU cycles ; ;Timing in this subroutine: (8080 cycles)[Z80 cycles] ; Trashes psw,c,de ;**************************************************** TIMSEC: mov c,a ;save no. of sectors ;Wait for initial sector lda NRSEFL+80h ;reset sector flag ;..and keep motor on NSTLP0: xra a ;(4)[4](stall) dad d ;(10)[11]bump timer (stall) adc b ;(4)[4]catch carry bit(stall) mov b,a ;(5)[4]b=high byte(stall) lda NBSTAT ;(13)[13]sector number and flag ora a ;(4)[4]wait for valid sector jp NSTLP0 ;(10)[10]NSSP is bit 7 ;Set up timer and timer incrementer. Match time outside loop below. mvi b,0 ;(7)[7]clear MSB of timer lxi h,0 ;(10)[10]clear rest of timer lxi d,1 ;(10)for incrementing lxi d,1 ;(10)stall ;Time b sectors using c,hl as the timer NSTLP2: lda NRSEFL+80h ;(13)[13]reset sector flag ;..and keep motor on NSTLP1: xra a ;(4)[4] dad d ;(10)[11]bump timer (de=1) adc b ;(4)[4]catch carry bit mov b,a ;(5)[4]b=high byte lda NBSTAT ;(13)[13]sector number and flag ora a ;(4)[4]wait for valid sector jp NSTLP1 ;(10)[10]NSSF is msb ;Inner loop: 50 cycles per spin nop ;(4)[4]stall xra a ;(4)[4] dad d ;(5)[6]make up for time outside loop adc b ;(4)[4]catch carry bit mov b,a ;(5)[4]b=high byte dcr c ;(5)[4]next sector jnz NSTLP2 ;(10)[10] ;Exactly 50 cycles outside the inner loop [49 for Z80] ;b,hl = total cycles ;Time/revolution (uS) = ((b,hl*50)/5)/CPU speed (MHz) ;Time/revolution (uS) = (b,hl*10)/CPU speed (MHz) ret ;***Subroutine*********************************** ; Print b,hl/de in decimal on the console, and ; compute result in binary in QOTENT ; On Entry: ; (b,hl)=Dividend ; de=divisor ; a = number of digits after decimal point ; On Exit: ; QOTENT = result in binary ; Trashes all registers ;************************************************ DIVIDE: mvi c,5 ;digit counter push h ;initialize quotent lxi h,0 shld QOTENT pop h DDLOOP: push psw ;save decimal point place push b ;save digit count ;Print decimal point if it's the right place cmp c mvi c,'.' cz PRINTC ;Compute & print one ASCII digit: c=((b,hl)/de)+'0' ;and compute b,hl = remainder X 10 call DECDIG ;compute/print digit ;Compute binary partial result in QOTENT push h push d lhld QOTENT ;multiply result so far by 10 mov d,h mov e,l dad h ;X2 dad h ;X4 dad d ;X5 dad h ;X10 mov a,c ;de-ASCII digit sui '0' mov e,a mvi d,0 ;de=new digit in binary dad d ;add in new digit shld QOTENT ;binary result so far pop d pop h mov a,b ;remainder high byte pop b ;recover c=digit count mov b,a ;but keep new high byte pop psw ;decimal point place ;See if we've done enough digits dcr c jnz DDLOOP ret ;---Local Subroutine-------------------------------- ; Divide hl by bc and print 1-digit result ; On Entry: ; (b,hl)=Dividend ; de=-(divisor) ; On Exit: ; Quotent has been printed in decimal ; (b,hl)=remainder X 10 ; c=current digit of quotent in ASCII ; trashes psw ;--------------------------------------------------- DECDIG: mov a,b ;a=dividend high byte lxi b,0FF00h+'0'-1 ;init c=ASCII quotient ;..(will go 1 too many) ;create b=MSB of divisor ;Divide a,hl by (b,de). The result will be an ASCII number ;in c, The remainder will be 16 bits on the stack push h ;set up stack DIGLP: inx sp ;chuck stack value inx sp ;pop to garbage push h ;remember prior result inr c ;bump quotent dad d ;add a negative number adc b ;catch carry bit jc DIGLP pop h ;hl=remainder ;c = quotent in ASCII, hl = remainder in binary ;Compute (b,hl) := hl X 10 (could be 19 bits) push d mov d,h ;temp save X1 mov e,l xra a mov b,a dad h ;X2 adc b ;b=0: catch carry dad h ;x4 adc a ;MSB dad d ;x5 adc b ;b=0: catch carry dad h ;X10 adc a ;MSB mov b,a ;(b,hl) = remainder X 10 pop d ;Fall into PRINTC to print quotent digit in c ;***Subroutine******************* ; Print character in c on console ; trashes psw ;******************************** PRINTC: mvi a,CONOUT ;Fall into GOBIOS ;***Subroutine********************** ; Go call a BIOS driver directly ; On Entry: ; c=value for BIOS routine, if any ; a = BIOS call address offset ; On Return: ; psw as BIOS left it ; all other regs preserved ;*********************************** GOBIOS: push h push d push b call DOBIOS pop b pop d pop h ret ;***Subroutine********************** ; Go call a BIOS driver directly ; On Entry: ; c=value for BIOS routine, if any ; a = BIOS call address offset ; On Return: ; all regs as BIOS left them ;*********************************** DOBIOS: lhld WBOOTA ;get BIOS base address mov l,a ;a has jump vector pchl ;'call' BIOS routine ;********************************* ; Disk Error Reporting Subroutines ;********************************* STUCK0: call CILPRT db 'Track 0 stuc','k'+80h jmp CPROC ;repair stack & quit NOSYNC: call CILPRT db 'No syn','c'+80h ret WPERR: call CILPRT db 'Write protec','t'+80h ret ;***Subroutine****************************** ;DSPDEC - Display value in b as one or two ; decimal digits (0-99 only) ; On Exit: ; Trashes psw,b,c ;******************************************* DSPDEC: mvi c,'0'-1 ;c contains 10's result in ASCII mov a,b ;a=value to convert DD10LP: inr c ;count 10's sbi 10 jnc DD10LP adi 10+'0' ;compute 1's digit in ASCII mov b,a ;save in b mov a,c ;leading zero in 10's digit? cpi '0' cnz PRINTC ;no, print 10's digit mov c,b ;print ones digit jmp PRINTC ;***Subroutine****************************** ;Test for Quit ('Q' or 'q') from user ; On Exit: ; a=0 and Z set if no chr ; Z clear and a=input chr if there was one ;******************************************* TESTQ: mvi a,CONST call GOBIOS ora a ;any chr waiting? rz ;N: ret with z set mvi a,CONIN call GOBIOS ;get the chr cpi 'A' ;letter? rc ;n: done ani 5fh ;strip parity, make upper case cpi 'Q' rnz ;z cleared ;fall into ABORT ;********************* ;Abort EPROM operation ;********************* ABORT: jmp CPROC ;============================ ; RAM Variables ;============================ CRTRAK: ds 1 ;current track, <0 means lost CRUNIT: ds 1 ;current unit (must follow CRTRAK) QOTENT: ds 2 ;Binary quotent result ds 80 ;40-deep stack STACK: END