pcat: BLK-enabled!

That INT 13H logic was a bit tricky to implement...

read-only for now.
This commit is contained in:
Virgil Dupras 2020-06-21 22:07:12 -04:00
parent 8d645405b3
commit dc7f36263a
3 changed files with 40 additions and 4 deletions

View File

@ -4,8 +4,8 @@ ORG @ 0x25 + HERE ! ( bypass BPB )
L1 FSET ( start )
CLI, CLD, AX 0x800 MOVxI, DS AX MOVsx, ES AX MOVsx,
SS AX MOVsx, STI,
AH 2 MOVri, DX 0 MOVxI, CH 0 MOVri, CL 2 MOVri, AL 12 MOVri,
BX 0 MOVxI, 0x13 INT, ( read sectors 2-14 of boot floppy )
AH 2 MOVri, DX 0 MOVxI, CH 0 MOVri, CL 2 MOVri, AL 15 MOVri,
BX 0 MOVxI, 0x13 INT, ( read sectors 2-15 of boot floppy )
( TODO: reading 12 sectors like this probably doesn't work
on real vintage PC/AT with floppy. Make this more robust. )
0x800 0 JMPf,

View File

@ -13,13 +13,14 @@ os.bin: xcomp.fs $(STAGE)
disk.bin: mbr.bin os.bin
cat mbr.bin os.bin > $@
dd if=$(EDIR)/blkfs of=$@ bs=512 seek=16
$(STAGE):
$(MAKE) -C $(EDIR) stage
.PHONY: emul
emul: $(TARGET)
qemu-system-i386 -fda $(TARGET)
qemu-system-i386 -drive file=$(TARGET),if=floppy,format=raw
.PHONY: clean
clean:

View File

@ -10,11 +10,46 @@ CODE (emit) 1 chkPS,
AX POPx, AH 0x0e MOVri, ( print char ) 0x10 INT,
;CODE
CODE (key)
AH AH XORrr, 0x16 INT, AH AH XORrr, AX PUSHx, ;CODE
AH AH XORrr, 0x16 INT, AH AH XORrr, AX PUSHx,
;CODE
CODE 13H08H ( driveno -- cx )
DI POPx, DX PUSHx, ( protect ) DX DI MOVxx, AX 0x800 MOVxI,
DI DI XORxx, ES DI MOVsx,
0x13 INT, DX POPx, ( unprotect ) CX PUSHx,
DI 0x800 MOVxI, ES DI MOVsx,
;CODE
CODE 13H ( ax bx cx dx -- ax bx cx dx )
SI POPx, ( DX ) CX POPx, BX POPx, AX POPx,
DX PUSHx, ( protect ) DX SI MOVxx, DI DI XORxx,
0x13 INT, SI DX MOVxx, DX POPx, ( unprotect )
AX PUSHx, BX PUSHx, CX PUSHx, SI PUSHx,
;CODE
: FDSPT 0x70 RAM+ ;
: _ ( dest secno )
( AH=read sectors, AL=1 sector, BX=dest,
CH=trackno CL=secno DH=head. )
0x0201 ROT ROT ( AX BX sec )
FDSPT @ /MOD ( AX BX sec trk )
2 /MOD ( AX BX sec head trk )
8 LSHIFT ROT OR 1+ ( AX BX head CX )
SWAP 8 LSHIFT ( AX BX CX DX )
13H 2DROP 2DROP
;
: FD@
2 * 16 + ( blkfs starts at sector 16 )
BLK( OVER _ BLK( 0x200 + SWAP 1+ _ ;
: FD! DROP ;
: FD$
( get number of sectors per track with command 08H. )
0 13H08H 0x3f AND FDSPT !
;
380 LOAD ( xcomp core high )
(entry) _
( Update LATEST )
PC ORG @ 8 + !
," BLK$ FD$ "
," ' FD@ BLK@* ! "
," ' FD! BLK!* ! "
EOT,
ORG @ 256 /MOD 2 PC! 2 PC!
H@ 256 /MOD 2 PC! 2 PC!