dragon-nx-32: more floppy work

diff --git a/Kernel/platform-dragon-nx32/floppy.s b/Kernel/platform-dragon-nx32/floppy.s
index ef37dfa..07927ea 100644 (file)
--- a/Kernel/platform-dragon-nx32/floppy.s
+++ b/Kernel/platform-dragon-nx32/floppy.s
@@ -102,9 +102,6 @@ fdsetup:
        sta     <FDCTRK         ; reset track register
        pshs    x,y
        cmpa    TRACK,x         ; target track
-;
-;      FIXME: what have we screwed up here so this always branches ???
-;
        beq     fdiosetup
 
        lda     TRACK,x
@@ -158,9 +155,9 @@ noprecomp:
        orcc    #0x50           ; irqs off or we'll miss bytes
        ldb     DIRECT,x
        cmpb    #0x01           ; read ?
-       beq     fdio_in_1
+       beq     fdio_in
        cmpb    #0x02
-       beq     wait_drq_1      ; write
+       beq     fdio_out        ; write
        sta     <FDCREG         ; issue the command
        nop                     ; give the FDC a moment to think
        exg     a,a
@@ -177,14 +174,14 @@ fdxferdone:
 ;
 ;      Relies on B being 2...
 ;
-wait_drq_1:
+fdio_out:
        sta     <FDCREG         ; issue the command
-       nop                     ; give the FDC a moment to think
-       exg     a,a
-       exg     a,a
+       ldx     DATA,x          ; get the data pointer
+       lda     ,x+             ; otherwise we don't have time
+                               ; to fetch it
 wait_drq:
-       bitb    <FDCREG
-       bne     drq_on
+       ldb     <0xFF23         ; check for DRQ the fastest way we can
+       bmi     drq_go          ; go go go...
        leay    -1,y
        bne     wait_drq
        ;
@@ -199,47 +196,48 @@ wait_drq:
 ;
 ;      Begin the actual copy to disk
 ;
-drq_on:
-       ldx     DATA,x
-       lda     ,x+
-       bra     drq_go
 drq_loop:
        sync
 drq_go:
        sta     <FDCDATA
+       ldb     <0xFF22         ; clear the FIR (PIA1DB)
        lda     ,x+
-       bra     drq_loop
+       bra     drq_loop        ; exit is via NMI
 
 ;
 ;      Read from the disk
 ;
-fdio_in_1:
-       sta     <FDCREG         ; issue the command
-       nop                     ; give the FDC a moment to think
-       exg     a,a
-       exg     a,a
 fdio_in:
+       sta     <FDCREG         ; issue the command
        ldx     DATA,x
 fdio_dwait:
-       ldb     <FDCREG
-       bitb    #0x02
-       bne     fdio_go
+       ldb     <0xFF23         ; wait on the PIA not fd regs.. quicker
+       bmi     fdio_go
+;
+;      Not ready, go round again
+;
+fdio_nogo:
        leay    -1,y
        bne     fdio_dwait
+;
+;      FIXME: do error recovery at some point (reset/poll)
+;
        ldb     fdcctrl
        stb     <FDCCTRL
        lda     #0xff
        rts
-;
-;      Now do the data
-;
-fdio_loop:
-       sync
+
 fdio_go:
+       lda     <FDCDATA        ; get the data first
+       ldb     <0xFF22         ; clear FIR
+       sta     ,x+             ; store the received byte
+fdio_loop:
+       sync                    ; stall for FIR
        ldb     <0xFF22         ; clear the FIR (PIA1DB)
        lda     <FDCDATA
        sta     ,x+
-       bra     fdio_loop
+       bra     fdio_loop       ; NMI terminates this
+
 
 ;
 ;      PIA management