Mercurial > hg > Members > kono > nitros9-code
changeset 2593:4c3c19ec3257
Added second vhd drive for MESS version 144 and newer. Will not alter
performance with older versions of MESS.
| author | robertgault |
|---|---|
| date | Sat, 24 Dec 2011 13:01:17 +0000 |
| parents | 7d8831f053ff |
| children | 3eeef3d4f272 |
| files | 3rdparty/drivers/emudsk/emudsk.asm |
| diffstat | 1 files changed, 53 insertions(+), 27 deletions(-) [+] |
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--- a/3rdparty/drivers/emudsk/emudsk.asm Sat Dec 24 12:48:56 2011 +0000 +++ b/3rdparty/drivers/emudsk/emudsk.asm Sat Dec 24 13:01:17 2011 +0000 @@ -6,6 +6,12 @@ * Ed. Comments Who YY/MM/DD * ------------------------------------------------------------------ * 01 Modified to compile under OS9Source tjl 02/08/28 +* 02 Modified to handle two .vhd drives R. Gault 11/12/23 +* Conforms to MESS v1.44 or more recent +* Added and enhanced some comments +* Note the forced > extended addressing in some cases. +* That is required as this code is relocatable but the +* addresses are fixed. Part of original code. * EmuDisk floppy disk controller driver * Edition #1 @@ -33,7 +39,8 @@ * $FF84-$FF85: 6809's 16-bit buffer address (cannot cross an 8K boundary due * to interference from the MMU emulation). buffer equ $FF84 pointer to the buffer - +* $FF86: controls .vhd drive 0=drive1 1=drive2 +vhdnum equ $FF86 * * Returns: * @@ -62,34 +69,39 @@ tylg set Drivr+Objct atrv set ReEnt+rev -rev set $01 +rev set $02 mod eom,name,tylg,atrv,start,size fcb $ff org 0 -u0000 rmb $FF Normal RBF device mem for 4 drives +u0000 rmb DRVBEG+(DRVMEM*2) Normal RBF device mem for 2 drives RG + rmb 255-. residual page RAM for stack etc. RG size equ . fcb $FF This byte is the driver permissions name fcs /EmuDsk/ - fcb 1 edition #1 + fcb 2 edition #2 RG * Entry: Y=Ptr to device descriptor * U=Ptr to device mem * * Default to only one drive supported, there's really no need for more. -INIT lda #$FF 'Invalid' value & # of drives - leax DRVBEG,u Point to start of drive tables - sta ,x DD.TOT MSB to bogus value - sta <V.TRAK,x Init current track # to bogus value - +* Since MESS now offers second vhd drive, EmuDsk will support it. RG +INIT ldd #$FF02 'Invalid' value & # of drives + stb V.NDRV,u Tell RBF how many drives + leax DRVBEG,u Point to start of drive tables +init2 sta DD.TOT,x Set media size to bogus value $FF0000 + sta V.TRAK,x Init current track # to bogus value + leax DRVMEM,x Move to second drive memory. RG + decb + bne init2 * for now, TERM routine goes here. Perhaps it should be pointing to the * park routine? ... probably not. TERM GETSTA clrb no GetStt calls - return, no error, ignore -L0086 rts + rts start lbra INIT 3 bytes per entry to keep RBF happy lbra READ @@ -101,11 +113,11 @@ * Entry: B:X = LSN * Y = path dsc. ptr * U = Device mem ptr -READ clra READ the sector +READ clra READ command value=0 bsr GetSect Go read the sector, exiting if there's an error - tstb + tstb msb of LSN bne GETSTA if not sector 0, return - leax ,x sets CC.Z bit + leax ,x sets CC.Z bit if lsw of LSN not $0000 bne GETSTA if not sector zero, return * LSN0, standard OS-9 format @@ -113,7 +125,10 @@ * LSN0 never changes after it's read in once. But we'll do it anyhow ldx PD.BUF,y Get ptr to sector buffer leau DRVBEG,u point to the beginning of the drive tables - ldb #DD.SIZ copy bytes over + lda PD.DRV,y Get vhd drive number from descriptor RG + beq copy.i go if first vhd drive + leau DRVMEM,u point to second drive memory +copy.i ldb #DD.SIZ copy bytes over copy.0 lda ,x+ grab from LSN0 sta ,u+ save into device static storage decb @@ -121,7 +136,9 @@ clrb rts -WRITE lda #$01 WRITE to emulator disk, and fall thru to GetSect +WRITE lda #$01 WRITE command = 1 + bsr GetSect Use same code as used by READ + rts * Get Sector comes here with: * Entry: A = read/write command code (0/1) @@ -129,25 +146,27 @@ * Y = path dsc. ptr * U = Device static storage ptr * Exit: A = error status from command register -GetSect tst <PD.DRV,y get drive number requested - bne DrivErr only one drive allowed, return error - - pshs x,b save LSN for later - stb >LSN +GetSect pshs x,d Moved up in routine to save command code. RG + lda PD.DRV,y Get drive number requested + cmpa #2 Only two drives allowed. RG + bhs DrivErr Return error if "bad" drive# + stb >LSN Tell MESS which LSN stx >LSN+1 - - ldx PD.BUF,y where the 256-byte LSN should go + ldx PD.BUF,y Where the 256-byte LSN should go + sta >vhdnum Set to MESS drive# RG * Note: OS-9 allocates buffers from system memory on page boundaries, so * the low byte of X should now be $00, ensuring that the sector is not * falling over an 8K MMU block boundary. +* This is the job of RBF not EmuDsk! RG stx >buffer set up the buffer address + puls a recover command sta >command get the emulator to blast over the sector - lda >command restore the error status - bne FixErr if non-zero, go fix the error and exit - puls b,x,pc restore LSN and exit + lda >command get the error status + bne FixErr if non-zero, go report the error and exit + puls d,x,pc restore registers and exit -DrivErr leas 2,s kill address of calling routine (Read/Write) +DrivErr leas 6,s kill address of calling routine (Read/Write) comb * FIND ERROR CODE TO USE * ldb #E$ find appropriate error code... @@ -225,7 +244,14 @@ ldb #E$UnkSvc return illegal service request error rts -park ldb #$02 close the drive +* This next is pointless for a virtual drive but probably does not hurt. +* MESS does not require this if hard drives are swapped in mid-stream. In +* real hardware, this is important as would be closing all open files. RG +park lda PD.DRV,y get drive number RG + cmpa #2 test for illegal value RG + bhs format ignore if illegal RG + sta $FF86 tell MESS which drive to halt RG + ldb #$02 close the drive stb >command save in command register format clrb ignore physical formats. They're not