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Text File | 1991-01-16 | 11.8 KB | 484 lines

; rename this IO-KP.DRV to RSXIO.INC for assembly with RSXMAST subttl 'DSKDRIVE machine dependant drivers' ; ; Most of this file can be used unchanged with any 1790 series ; disk controller chip. The actual seek mechanism, at the end, ; will have to be customized. This version is for the 1983 ; style Kaypro 4. The kp84 equate converts to the 1984 model, ; BUT HAS NOT BEEN CHECKED. ; ; rdhst/wthst read or write to/from buff from/to hstrk/hstsec. ; One physical block is transferred. Errflg is set to zero on ; a good transfer, else non-zero. This is the total responsiblity ; of this portion of the system. It refers to the extended disk ; parameter tables for host configuration. ; ; Set only one of the following true (choose Kaypro model) k83 equ true k84 equ false; *** NOT checked. CAUTION *** k10 equ false; *** NOT checked. Kaypro 10 *** ; ; This option, when set yes, increases disk transfer time detect equ no; yes to detect disk not mounted ; no to wait for disk to be mounted ; ; 1791/2/3 Controller chip specific ; For most Z80 implementations the data request and interrupt from ; the 1791 is connected to NMI (possibly gated by the CPU halt ; status line). Thus a CPU halt is ended by the appropriate ; controller status, with the RET instruction in memory location ; 066h. A status read after the interrupt will reset the interrupt, ; as will satisfying the data request. 8080s need more hardware. wrtmsk equ 0FDH; Status bits useful after write rdmask equ 09DH; " " read clrcmd equ 000H; home disk rdcmd equ 08CH; read physical sector wtcmd equ 0ACH; write physical sector radrcmd equ 0C4H; read address command seekcmd equ 014H; seek track ficmd equ 0D0H; clear controller. ; ; Z80 opcodes used in driver outi macro db 0edh,0a3h endm ini macro db 0edh,0a2h endm ; ; This writes a physical sector to the disk. The size, etc. ; of that sector are controlled by the extended disk parameter ; tables. All i/o is performed to/from buff. ; a,f,b,c,d,e,h,l wthst: call rwtbgn wthst1: ei; during seeks call setup; (disables interrupts) jnz rwtxit mvi e,wtcmd; write command rrc jnc wthst2; Not 128 byte physical rcd mvi b,128 call dcmnde jmp w256 wthst2: mvi b,0 rrc jnc wthst3; Not 256 byte physical rcd call dcmnde jmp w256 wthst3: rrc jnc wthst4; 1024 byte physical rcd call dcmnde jmp w512; 512 byte physical rcd wthst4: call dcmnde ; " " w1024: hlt; Else 1024 byte rcd. outi; *** Z80 code jnz w1024 w768: hlt outi jnz w768 w512: hlt outi jnz w512 w256: hlt outi jnz w256; May be a W128, on entry bc call notbsy ani wrtmsk jz rwtxit call clear dcr d jnz wthst1; retry ori 0FFH; Signal error jmp rwtxit ; ; Set up NMI return, save controller track setting. ; Sets the number of retries to be performed. ; a,f,d rwtbgn: lda 0066H sta save66 mvi a,0C9H; "RET" instruction for NMI sta 0066H in trkreg sta trksav mvi d,10; retries ret ; ; Similar to wthst, reads from disk into buff, using the ; extended parameter table. ; a,f,b,c,d,e,h,l rdhst: call rwtbgn rdhst1: ei call setup; (disables interrupts) jnz rwtxit mvi e,rdcmd; read command rrc jnc rdhst2; Not 128 bytes per phys. block mvi b,128 call dcmnde jmp r256 rdhst2: mvi b,0; i.e. 256 rrc jnc rdhst3; Not 256 bytes per block call dcmnde jmp r256 rdhst3: rrc jnc rdhst4; 1024 byte physical record call dcmnde jmp r512; 512 bytes per block rdhst4: call dcmnde ; " " r1024: hlt; else 1024 bytes per block ini; *** Z80 code jnz r1024 r768: hlt ini jnz r768 r512: hlt ini jnz r512 r256: hlt ini jnz r256; May be r128, on entry (b) call notbsy ani rdmask jz rwtxit call clear dcr d jnz rdhst1; retry ori 0FFH; Signal error ; " " ; Exit, restoring 66, trkreg, setting errflg on (a) rwtxit: push psw lda save66 sta 0066H lda trksav; restore the controller, in out trkreg; case bios assumes unchanged pop psw ei sta errflg ret ; ; The actual selection and addressing of the disk controller. This ; is responsible for address conversion, and uses the extended disk ; parameter table. z flag for success, nz for failure. d preserved. ; a,f,b,c,e,h,l setup: lhld hsttrk shld adrtrk lda hstsec sta adrsec xra a sta side; default use side 0 lda config ani 0fh; remove density selection cpi maxcase+1 jnc error lxi h,cases; Execute the appropriate code call docase; This varies with the format call seek; being read/written. ; " " ; Setup registers for read/write commands lda hstblk; block size in 128 byte records mvi c,datapt; port to read/write data from/to lxi h,buff; and where to/from di; Can't interrupt during rd/wrt ret; with z/nz flag from seek ; ; docase (a) on table (hl)^ to muck with disk addressing. ; a,f,h,l (and the destination code) docase: add a add l mov l,a adc h sub l mov h,a mov a,m inx h mov h,m mov l,a pchl ; cases: dw case0, case1, case2 dw case3, case4 ; ; Native and logical addresses are the same case0: ret ; ; logical sectors from 0 to offsec-1 are on side 0. ; from offsec up are on side 1, and addressed by adding nsecs. ; a,f,h,l case1: lda adrsec; config = 1 lxi h,offsec sub m rc lxi h,nsecs add m sta adrsec ; " " ; set side one to be accessed ; a,f sside1: mvi a,1 sta side ret ; ; odd logical tracks on side 1, even on side 0. ; physical track address = logical track/2 ; Side 1 uses an offset to the sector address. ; a,f,h,l case2: lhld adrtrk mov a,l ani 1 sta side mov a,h rar mov h,a mov a,l rar mov l,a shld adrtrk rnc; on side 0 lxi h,nsecs lda adrsec; side 1, correct sector address add m sta adrsec ret ; ; 1st ntrks are on side 0, others side 1. For logical track ; on side 1, physical track is logical track - ntrks. ; a,f,h,l case3: lda adrtrk lxi h,ntrks cmp m; tracks per side rc sub m; On second side sta adrtrk jmp sside1 ; ; 1st ntrks are on side 0, others on side 1. For side 1 track ; numbers count down from ntrk, i.e. the disk looks like ; ; side0 0 1 2 . . ntrk-1 ; side1 2ntrk-1 . . ntrk+1 ntrk (CPM86 on IBM PC) ; a,f,h,l case4: lda adrtrk lxi h,ntrks cmp m rc; On first side cma add m add m; Now we count down sta adrtrk jmp sside1 ; ; Haven't the vaguest idea how to address this disk ; a,f error: ori 0FFH; config unknown, error sta dsktrk; and mark disk unused ret ; ; Clear disc controller. nz flag for timeout ; a,f clear: mvi a,clrcmd; reset controller call dcmnd call notbsy ani 1 rnz; timed out sta dsktrk ret ; ; await not busy controller status ; a,f notbsy: push h lxi h,0 call dkwait pop h ral; restore status ret; with busy bit (1) if time out ; ; Timed out wait for non-busy controller. Time varies with hl ; Carry set for timeout. (a) is status right shifted ; a,f,h,l dkwait: in statpt rar rnc; not busy, ok if detect dcr l; preserve status in a jnz dkwait; for possible time-out exit dcr h; (re-getting may be different) jnz dkwait push psw; busy time-out, save status bits mvi a,ficmd call dcmnd; clear controller chip pop psw; show status bits stc; and signal error ret else; not detect jmp dkwait endif ; ; command (e) to disk controller ; a,f dcmnde: mov a,e ; " " ; command (a) to disk controller. Pause for status valid ; f dcmnd: out ctrlpt push b; and 20 uSec. delay mvi b,(20*clkspd - 37)/14; clkspd >= 3(00 khz) dcmnd1: dcr b jnz dcmnd1; pause for controller status pop b ret ; ; pause (b) * 10 Millisec. Set for 2.5 Mhz clock. ; a,f,b pause: push d pause1: lxi d,41*clkspd; clkspd in 100khz units pause2: dcx d mov a,e ora d jnz pause2 dcr b jnz pause1 pop d ret ; ; ================================================================= ; Everything above this point probably does not have to be changed ; for any machine using the 1790 series disk controllers. The rest ; will have to be customized. ; ================================================================= ; ; Kaypro Specific sideb equ 2; side selection, bit number drvmsk equ 3; bits 0 & 1 select drive densb equ 32; bit weight for density selection ; if k83; 1983 version bitpt equ 1ch; system control port mtrb equ 6; bit number mtron equ 0 abit equ 0; bit number bbit equ 1; bit number side0 equ 0 side1 equ 1 shl sideb endif if k84 or K10; 1984 version bitpt equ 14H; system control port mtrb equ 4; bit number mtron equ 1 abit equ 1; bit number bbit equ 0; bit number side0 equ 1 shl sideb side1 equ 0 endif drivea equ 1 shl abit driveb equ 1 shl bbit ; ; Field to be controlled here modmsk equ drvmsk+(1 shl mtrb)+(1 shl sideb)+densb ; ; Host specific routines here - setup for Kaypro 4 ; This performs the actual seek, sets density, etc. ; *** ENTRY IN THE MIDDLE at "seek" *** <<< ; a,f,b,c,e,h,l (allowed). (d is retry count) ; seek3: call clear; Never used yet, clear controller jnz error; timeout error, no disk mounted seek4: lda adrtrk; Do physical seek out datapt; changing tracks mvi a,seekcmd; seek track call dcmnd call notbsy ani 99H; Check status jz seek5; good seek, finish up ani 1 jnz error; no disk, error exit call error; mark physical seek needed dcr d jz error; no more retries, error ; " " ; Main routine entry point. <<< *** ENTRY HERE << seek: lda dsktrk; If we have switched drives out trkreg; set the controller to match history ; " " ; set up density lda config; Set up for side and density ora a lxi h,dendbl jp seek1; Normal double density system inx h; else set single density command seek1: mov b,m ; " " ; set up side selection lda side; Move side selection bit into place. if k84 OR k10; Side bit is complemented cma endif ani 1 ral; Position the side select bit ral ora b; Compute drive selection/density code mov b,a ; " " ; Kaypro combines all these things in one port in bitpt; Keep bank (80), turn mtr on (40=0) push psw; clear DDEN (20), keep lptstrobe (10) ani NOT modmsk; ignore prtbusy(8), clear side(4), ora b; drive code (2, 1) bit weights ori mtron shl mtrb ; " " ; add in the physical drive selection coding. lxi h,dskode ora m ; " " ; now we actually select drive/side/density and turn on motors out bitpt pop psw ani 1 shl mtrb if k84 OR k10; inverted motor control bit xri mtron shl mtrb endif mvi b,50; *10 = 500 millisec cnz pause; if motor was off wait for it lda dsktrk inr a; check for 1st access to this drv jz seek3; 1st access to this drive dcr a lxi h,adrtrk cmp m jnz seek4; Need a physical seek ; " " ; All well, final setup and exit seek5: if detect mvi a,radrcmd call dcmnd; try to read an address call notbsy ani 1 jnz error; busy time out, no disk endif; detect lda adrsec; Successful seek or not needed lxi h,sec1st; last buggery with sec. address add m out secreg; set physical sector lda adrtrk sta dsktrk; record what track we are on xra a ret ; ; These four bytes following MUST BE the last portion of this file. ; This makes them accessible by a negative offset from the "info" ; pointer, which is returned by the master RSX enquiry call, and ; allows supporting software to dynamically reconfigure the system. ; This portion must be customized on installation to host only. ; modrv: db drv-'A'; and drive id to use (0=A). patchable ; dskode: if k10; Only 1 floppy drive db drivea; addressed as C. else db driveb; drive selection coding. drive B endif dendbl: db 0; base command for double density densgl: db densb; base command for single density í