dhollis@shiloh.UUCP (Dan Hollis @ 7819367) (07/08/90)
This message is primarily directed at Allan Pratt, and the TOS folks at Atari corp. (but I would love a response from ANYONE!).. Is there some way to 'fake out' TOS, and force a media change via software? If so, is there a 'legal' way to do it? If not a 'legal' way, then how do you do it anyways? Any responses would be appreciated...
csbrod@medusa.informatik.uni-erlangen.de (Claus Brod ) (07/09/90)
dhollis@shiloh.UUCP (Dan Hollis @ 7819367) writes: >Is there some way to 'fake out' TOS, and force a media change via software? >If so, is there a 'legal' way to do it? If not a 'legal' way, then how do >you do it anyways? Any responses would be appreciated... Simple. Link into the hdv vectors. Let them point to routines that return 2 (hdv_mediach), -14 (hdv_rw), or deinstall themselves (hdv_bpb), i.e. something like this: my_rw: move.w $e(a7),d0 ; drive to read/write cmp.w ourdrive(pc),d0 ; drive to fake media change on? bne.s rw2 ; no, goon moveq #-14,d0 ; Media changed rts rw2: move.l old_rw(pc),a0 ; get old rw vector jmp (a0) ; jump to the old routine my_med: move.w 4(a7),d0 ; drive to check media status cmp.w ourdrive(pc),d0 ; drive to fake media change on? bne.s med2 moveq #2,d0 ; media changed rts med2: move.l old_media(pc),a0 ; get old mediach vector jmp (a0) my_bpb: move.w 4(a7),d0 ; drive to get BPB from cmp.w ourdrive(pc),d0 ; you know which drive-... bne.s bpb2 move.l old_rw(pc),hdv_rw ; restore vectors move.l old_media(pc),hdv_med move.l old_bpb(pc),hdv_bpb move.l old_bpb(pc),a0 jmp (a0) After you've done that, do some dummy GEMDOS call like Fopen("X:\\YYYY") where X is the drive where the media changed shall be faked on and YYYY is a file name that may or may not exist. In this moment, GEMDOS calls the BIOS routines: Mediach() and Rwabs() return 'changed', so GEMDOS calls Getbpb() to reinitialize drive data. It also forgets all about the drive, including folder info and things like this. Remember to use XBRA when linking into the BIOS vectors (I omitted that for reasons of brevity). The code above is not guaranteed to work - it's 2 a.m. and I badly need to sleep. By the way: You'll find a detailled description on how to this in the TOS 1.4 release notes. ---------------------------------------------------------------------- Claus Brod, Am Felsenkeller 2, Things. Take. Time. D-8772 Marktheidenfeld, West Germany (Piet Hein) csbrod@medusa.informatik.uni-erlangen.de ----------------------------------------------------------------------
jhenders@van-bc.wimsey.bc.ca (John Henders) (07/09/90)
Re: Forcing media change.
There is a pd autoboot program around called FMC,I believe,which will force a
media change on your floppy drives. If you need to do this in your own program,
I did it once by stealing the vector at $47e,then using this little routine to
replace it.
my_mc:
move.w 4(a7),d0 * drive?
move.l sys_vec,a0
cmp.w #$c,d0 * you talking to me?
bne .sk1 * no get lost
cmp.w #0,dc_flg1 * copied a disk lately?
beq .sk2 * no then use rd vec
move.l #ret_err,a0 * otherwise tell tos to look again
.sk1 jmp (a0)
.sk2 move.l sav_vec,a0
jmp (a0)
ret_err:
moveq.w #2,d0 * disk has definately been changed
move.w #0,dc_flg1 * only need to check once
rts
Note that this was written to support loading a ramdisk (M) with a floppy
as a sort of an un-Turtle program. The system would not look at a ramdisk
for a media change as I loaded the ramdisk by using the ramdisk memory as a
track buffer.
ljdickey@water.waterloo.edu (L.J.Dickey) (07/10/90)
In article <204@shiloh.UUCP> dhollis@shiloh.UUCP (Dan Hollis @ 7819367) writes: >Is there some way to 'fake out' TOS, and force a media change via software? >If so, is there a 'legal' way to do it? If not a 'legal' way, then how do >you do it anyways? Any responses would be appreciated... While browsing through some programs in the directory "diskutils" at "terminator", I came across a program called "fmc" (for Force Media Change). I have not tried it, but this might be just what you want. I don't know how many or which versions of the OS this works for.