FORMAT.Text

.Page ;++ ; Format ; ;-- ; REGISTERS ; IN ; All = Any value ; OUT ; All = Destroyed ; ; CALLS ; ClrBuf Clears 524 byte buffer and other variables ; SelSide Selects side ; Recall Recalibrates disk to optical index sensor ; WriTrk Write no. of sectors in TempSec ; VerTrk Verifies no. of sectors in TempSec ; SeekAlt Seeks the teack in IIob+Track and sets speed ; WrSynTrk Writes bitslip FF's and A9's then sector 0 ; WArd16 Write sector x, both header and data fields ; RdAdr Reads sector header ; Read16 Reads data fields ; VfyCksum Verifies checksum that was read ; PreNib Prenibblizes certain bytes for timing purposes ; ;++ .Page Format .Equ * ; Format entry point FormTrk .Equ * Jsr ClrBuf ; Clear the buffer to be written Lda #7 Sta FmtGap Jsr RecalMtr ; Turn on motor & start from a known point (Track 0 ) Bcs FormRts ; Abort upon error from Recal FormTop Jsr SeekAlt ; Go to othe track in IIob+Track & set speed Ldy CurClass Lda SecPrtTrk,y ; Fetch number of sectors in current track Sta TempSec ; Save it for WriTrk Jsr WriTrk ; Write a track full of sectors Lda IIob+Command ; If a format track Cmp #FrmTrk ; Then we're done-exit the routine Beq VT00 ; Command = FormatTrack (5) Lda Iob+NoSides ; 1 = single side, 2 = double side Cmp #2 Bne $39 ; if <> 2 then go to incr to next track Lda #20 Sta IIob+Side Jsr WriTrk ; Now write second side Lda #00 Sta IIob+Side ; Restore to side 0 $39 Inc IIob+Track Lda IIob+Track Cmp #MaxTrack+1 Bcc FormTop ; Until we run out of tracks Dec IIob+Track Bne VT00 ; Skip tunring the motor on Verify .Equ * ; Verify entry point Lda #MaxTrack Sta IIob+Track ; From inside of disk to outer edge VerTrk .Equ * Jsr RecalMtr ; Turn on motor & start from a know point ( track 0 ) Bcs FormRts ; Abort upon error from Recal VT00 .Equ * Jsr SeekAlt ; Go to track in IIob+Track & set speed Ldy CurClass Lda SecPrTrk,y ; Fetch the number of sectors in current track Sta TempSec ; Save it for WriTrk routine Jsr VerTrk Bcs FormErr ; Error, exit from routine Lda IIob+Command ; If a verify track Cmp #FrmtTrk ; Then we're done-exit the routine Bcs $41 ; Command = FormatTrack (5) or VerifyTrack (6) Lda Iob+NoSides ; 1 = Single side, 2 = double side Cmp #2 Bne $39 Lda #20 Sta IIob+Side Jsr VerTrk ; Now verify side 1, track x Bcs FormErr ; Error, exit from routine Lda #00 Sta IIob+Side $39 Dec IIob+Track Bpl VT00 $41 Clc Rts FormErr Lda IIob+Track ; Current track number Sta Trkjl0dNumb ; Save for host's usage Lda IIob+Side ; Current side And #20 ; leave bit 5 -- side bit Beq $17 Lda #1 $17 Sta SideNumb ; Save for host's usage Lda #SErrFrmt ; Format error code FormRts Rts TooSml .Equ * .Byte 0., 5., 10., 15. ; Not used .Byte 20., 25., 30., 35. ; 4:7 .Byte 40., 45., 50., 55. ; 8:11 .Byte 60., 65., 70., 75. ; 12:15 JustRit .Equ * .Byte 108., 99., 90., 81., 72. ; Sectors in class * 9 bytes per sector ;++ ; Wri…