Emulate empty floppy drive and CD-ROM drive

frank-deng commented 7 months ago

Is your feature request related to a problem? Please describe.

No response

What you want

Is it possible to emulate a scenario where Floppy/CD-ROM is present but without floppy disk/CD-ROM disc inserted, like VirtualBox does.

Describe alternatives you've considered

No response

Additional information

No response

Have you checked that no similar feature request(s) exist?

[X] I have searched and didn't find any similar feature request.

Code of Conduct & Contributing Guidelines

[X] I agree to follow the code of conduct and the contributing guidelines.

rderooy commented 7 months ago

Yes, there should be an option for imgmount to "mount" an empty drive. Especially for running Win9x this would be helpful. The work-around for now is to always have some media in the drive, which for a floppy drive can be an empty disk.

For floppy, this will also require setting the floppy drive type.

joncampbell123 commented 7 months ago

Yes! Not everybody 1990s kid booted their computers with a floppy and a CD inserted in the drives. :)

joncampbell123 commented 7 months ago

I got an initial implementation for mounting an empty floppy and empty CD-ROM drive finished.

Latest commit:

IMGMOUNT 0 -fs none -t floppy -empty IMGMOUNT e: -t iso -empty

rderooy commented 7 months ago

@joncampbell123 nice!

But you should probably add a flag to set the floppy BIOS type, otherwise some software will get confused. I'm thinking of Win9x thinking you have a 5.25" drive (type 2), while you are wanting to use 3.5" 1.44MB (type 4).

joncampbell123 commented 7 months ago

@joncampbell123 nice!

But you should probably add a flag to set the floppy BIOS type, otherwise some software will get confused. I'm thinking of Win9x thinking you have a 5.25" drive (type 2), while you are wanting to use 3.5" 1.44MB (type 4).

It's going to have to be a 1.44MB drive for now, but I'll address that after release March 1st.

joncampbell123 commented 7 months ago

Actually, I added support for the -size numbers for the empty drive, and it will try to match BIOS floppy type code too. That should complete this request.

rderooy commented 7 months ago

I'm not sure what the issue is here, but compiled the latest code and cannot seem to mount an empty floppy or CD-ROM disk drive. some things I tried:

joncampbell123 commented 7 months ago

Syntax changed.

It is now:

IMGMOUNT 0 empty -t floppy -fs none

and

IMGMOUNT e: empty -t cdrom

The file name "empty" is now handled as a special name that means "empty drive".

This was done to clean up the code and to make it possible to mount "empty" along with other disk images to a drive so you can use "Swap Floppy" and "Swap CD" mapper shortcuts to rotate between empty and other disk images.

rderooy commented 7 months ago

Thanks,

That works for a 3.5" and CD-ROM drive, it does not seem to work for a 5.25". Or at least, after booting Win98SE it only saw the first floppy drive.

IMGMOUNT 0 empty -fs none -t floppy
IMGMOUNT 1 empty -fs none -t floppy -size 512,80,2,15
IMGMOUNT C hdd.img -ide 1m
IMGMOUNT D empty -t iso -ide 2m

Also, when I tried to mount a CD from the drop-down menus (DOS -> Change current CD image) while running Win98SE, DOSBox-X segfaulted.

Doing the same with a 3.5" diskette image did work.

joncampbell123 commented 7 months ago

Thanks,

That works for a 3.5" and CD-ROM drive, it does not seem to work for a 5.25". Or at least, after booting Win98SE it only saw the first floppy drive.
IMGMOUNT 0 empty -fs none -t floppy
IMGMOUNT 1 empty -fs none -t floppy -size 512,80,2,15
IMGMOUNT C hdd.img -ide 1m
IMGMOUNT D empty -t iso -ide 2m
Also, when I tried to mount a CD from the drop-down menus (DOS -> Change current CD image) while running Win98SE, DOSBox-X segfaulted.

Doing the same with a 3.5" diskette image did work.

Remember that -size is sz,S,H,C not sz,C,H,S.

IMGMOUNT 1 empty -fs none -t floppy -size 512,15,2,80

That's how the original DOSBox project defined it and DOSBox-X follows that for compatibility.

rderooy commented 7 months ago

Thanks for the correction. But it makes no difference, Win98SE still does not show the drive B icon. Here is what the logs print for the mount commands.

LOG: FAT: Partition type is MBR (IBM PC)
LOG: Mounted FAT volume is FAT32 with 514573 clusters
LOG: Mapping BIOS DISK C/H/S 1023/64/63 as IDE 4092/16/63
LOG: IMGMOUNT: HDD image mounted to drive no. 2 (IDE Primary Master)
LOG: Mounted empty C/H/S/sz 80/2/18/512 1440KB
LOG: Updating floppy type to 8 BIOS type 0x02
LOG: Mounted empty C/H/S/sz 80/2/15/512 1200KB
LOG: Empty ISO
LOG: IMGMOUNT: CD-ROM image mounted to drive D (IDE Secondary Master)

rderooy commented 7 months ago

Some further testing show that the issue seems to be that Win98SE only sees the first floppy drive, regardless of configuration. If I swap the two around such that A: becomes 5.25" and B: becomes 3.5", Win98SE will only show the 5.25" A: drive.

joncampbell123 commented 7 months ago

For whatever reason I can't get Windows 95 to see more than one floppy drive.

I also cannot get Windows 95 to talk to the floppy controller emulation. I don't mean like it pokes that the I/O ports and rejects it, I mean it absolutely won't even try to probe the FDC to talk to it. It doesn't try anything and then complains that the FDC is not present or working.

frank-deng commented 6 months ago

When I boot into real DOS with an empty CD-ROM drive, then load CD-ROM disc from menu "DOS->Change current CD image...", the whole emulator will CRASH!

Changing floppy disk from menu "DOS->Change current floppy image..." works well without crashing when booting into real DOS with empty floppy drives.

Also is it possible to add an action "Leave Empty" apart from Yes and No for this dialog? So as to emulate removing media from Floppy/CDROM drive.

joncampbell123 / dosbox-x