mirror of
https://github.com/hsoft/collapseos.git
synced 2024-11-23 19:28:06 +11:00
80d1b59050
Splitting a word into MSB/LSB pairs happens often and is worth, I think, native words. Also, I'm going to need it in the upcoming commits.
89 lines
2.7 KiB
Forth
89 lines
2.7 KiB
Forth
( ----- 600 )
|
|
PC/AT recipe
|
|
|
|
602 MBR bootloader 604 KEY/EMIT drivers
|
|
606-608 BLK drivers 610 AT-XY drivers
|
|
612 xcomp unit
|
|
( ----- 602 )
|
|
H@ ORG ! 0x7c00 BIN( ! ( BIOS loads boot bin at 0x7c00 )
|
|
JMPs, L1 FWRs ( start )
|
|
ORG @ 0x25 + HERE ! ( bypass BPB )
|
|
L1 FSET ( start )
|
|
CLI, CLD, AX 0x800 MOVxI, DS AX MOVsx, ES AX MOVsx,
|
|
SS AX MOVsx, DX PUSHx, ( will be popped by OS ) STI,
|
|
AH 2 MOVri, DH 0 MOVri, 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,
|
|
ORG @ 0x1fe + HERE ! 0x55 C,* 0xaa C,*
|
|
( ----- 604 )
|
|
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
|
|
( ----- 606 )
|
|
CODE 13H08H ( driveno -- cx dx )
|
|
DI POPx, DX PUSHx, ( protect ) DX DI MOVxx, AX 0x800 MOVxI,
|
|
ES PUSHs, DI DI XORxx, ES DI MOVsx,
|
|
0x13 INT, DI DX MOVxx, ES POPs, DX POPx, ( unprotect )
|
|
CX PUSHx, DI PUSHx,
|
|
;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
|
|
( ----- 607 )
|
|
: FDSPT 0x70 RAM+ ;
|
|
: FDHEADS 0x71 RAM+ ;
|
|
: _ ( AX BX sec )
|
|
( AH=read sectors, AL=1 sector, BX=dest,
|
|
CH=trackno CL=secno DH=head DL=drive )
|
|
FDSPT C@ /MOD ( AX BX sec trk )
|
|
FDHEADS C@ /MOD ( AX BX sec head trk )
|
|
8 LSHIFT ROT OR 1+ ( AX BX head CX )
|
|
SWAP 8 LSHIFT 0x03 C@ ( boot drive ) OR ( AX BX CX DX )
|
|
13H 2DROP 2DROP
|
|
;
|
|
( ----- 608 )
|
|
: FD@
|
|
2 * 16 + ( blkfs starts at sector 16 )
|
|
0x0201 BLK( 2 PICK _
|
|
0x0201 BLK( 0x200 + ROT 1+ _ ;
|
|
: FD!
|
|
2 * 16 + ( blkfs starts at sector 16 )
|
|
0x0301 BLK( 2 PICK _
|
|
0x0301 BLK( 0x200 + ROT 1+ _ ;
|
|
: FD$
|
|
( get number of sectors per track with command 08H. )
|
|
0x03 ( boot drive ) C@ 13H08H
|
|
8 RSHIFT 1+ FDHEADS C!
|
|
0x3f AND FDSPT C!
|
|
;
|
|
( ----- 610 )
|
|
: COLS 80 ; : LINES 25 ;
|
|
CODE AT-XY ( x y )
|
|
( DH=row DL=col BH=page )
|
|
AX POPx, BX POPx, DX PUSHx, ( protect )
|
|
DH AL MOVrr, DL BL MOVrr, BX BX XORxx, AH 2 MOVri,
|
|
0x10 INT, DX POPx, ( unprotect )
|
|
;CODE
|
|
( ----- 612 )
|
|
0xff00 CONSTANT RS_ADDR
|
|
0xfffa CONSTANT PS_ADDR
|
|
RS_ADDR 0x80 - CONSTANT SYSVARS
|
|
30 LOAD ( 8086 asm )
|
|
262 LOAD ( xcomp ) 270 LOAD ( xcomp overrides )
|
|
445 461 LOADR ( 8086 boot code )
|
|
353 LOAD ( xcomp core low )
|
|
604 LOAD ( KEY/EMIT drivers )
|
|
606 608 LOADR ( BLK drivers )
|
|
610 LOAD ( AT-XY drivers )
|
|
390 LOAD ( xcomp core high )
|
|
(entry) _ ( Update LATEST ) PC ORG @ 8 + !
|
|
," BLK$ FD$ ' FD@ BLK@* ! ' FD! BLK!* ! " EOT,
|