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720k ... master

Author SHA1 Message Date
Juhani Krekelä e161d14321 Reset floppy disks upon read failure 2022-03-29 09:01:56 +03:00
Juhani Krekelä 48436ef9bd Put debug output behind debug define in io.asm 2022-03-29 09:01:56 +03:00
3 changed files with 9 additions and 18 deletions

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@ -2,7 +2,7 @@ DOSBOX=dosbox -conf dosbox-build.conf -exit
ordos.img: BOOT.BIN IO.SYS ORDOS.SYS COMMAND.COM debug.com edlin.com exe2bin.exe link.exe masm.exe
rm -f ordos.img
mkfs.fat -C $@ 720
mkfs.fat -C $@ -M 0xff 320
rw -I 0x7c00 -i BOOT.BIN -o $@ -c 512
mcopy -i $@ IO.SYS ::
mcopy -i $@ ORDOS.SYS ::

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@ -17,12 +17,12 @@ jmp code
dw 512 ; Bytes per sector
db 2 ; Sectors per cluster
dw 1 ; Reserved sectors
fats db 2 ; FATs
db 2 ; FATs
dw 112 ; Root directory entries
dw 2*720 ; Total sectors
db 0f9h ; Media descriptor
sectorsperfat dw 3 ; Sectors per fat
sectorspertrack dw 9
dw 2*320 ; Total sectors
db 0ffh ; Media descriptor
dw 1 ; Sectors per fat
sectorspertrack dw 8
heads dw 2
dd 0 ; Hidden sectors
dd 0 ; Total sectors (large)
@ -40,7 +40,7 @@ code:
mov drivenumber, dl
; TODO: Check we actually have the OS
mov ax, 14
mov ax, 10
mov bx, 600h
mov cx, 17 ; This is what PC-DOS 1.10's full size ends up at
call loadsectors

13
io.asm
View File

@ -568,15 +568,14 @@ code ends
constants segment
sectorspertrack dw 9 ; TODO: Don't hardcode
sectorspertrack dw 8 ; TODO: Don't hardcode
heads dw 2 ; TODO: Don't hardcode
disks_table:
db 1 ; 1 drive, TODO: Don't hardcode
db 0 ; Physical drive 0
;dw offset iogroup:parameters_320k
dw offset iogroup:parameters_720k
dw offset iogroup:parameters_320k
parameters_320k:
dw 512 ; Sector size in bytes
@ -586,14 +585,6 @@ parameters_320k:
dw 112 ; Number of directory entries
dw 320*2 ; Number of sectors
parameters_720k:
dw 512 ; Sector size in bytes
db 2 ; Sectors per cluster
dw 1 ; Number of reserved sectors
db 2 ; Number of FATs
dw 112 ; Number of directory entries
dw 720*2 ; Number of sectors
doubleticks_per_hour dw 32772 ; 1800B0h / 2 / 24
ticks_per_minute dw 1092 ; 1800B0h / 24 / 60
ticks_per_second dw 18 ; 1800B0h / 24 / 60 / 60