Update - making a bit of progress

On Ubuntu desktop at home, I'm getting it to pick up the images and format c: - but the sizes are all screwed up.

Using BXImage to create a 512 MB partition (512,63,16,1040) - FDISK only "sees" 8 MBs.

When I went up to 800 MB IMG file size, FDISK saw 238 MBs or so. But when I went up to 1 GB, FDISK only saw 16 MBs.

This is confusing!!! I'm following the instructions by the book based off what is output by BXImage - what am I doing wrong here?

[Thread moved to DOSBox General Section]

I think you should ask whoever is making this DOSBox for Android.

f00dl3 wrote:

Using BXImage to create a 512 MB partition (512,63,16,1040) - FDISK only "sees" 8 MBs.- what am I doing wrong here?

DOSBOX sees image within INT 13h limitation, just like how real DOS see it.

512 bytes / sectors
63 max sectors per cylinders
255(256?) max 'heads' (sides)
1024 max 'cylinders' (tracks).

1040 mod 1024 = 16
so, 512*63*16*16 = 8,257,536 bytes about 8MBs

so, make sure hdd images MUST conform to INT 13h specification or else!

Ok - so that kind of makes some sense.

Thing is I know DOS is fully capable of reading 800 MB hard disks - the first Packard Bell Legend 300 CD I had with Windows 3.11 had 850 MBs or some weird # up there.

If the max 16h sector size is 1024 - how could I fool DOS Box to read a 850 MB disk image? BXImage by default creates it with 512 / 63 / 16 / * sizes - can I create it that way but mount it in DOS Box differently? I know if I want to have any chance of a Windows 95 install working I need more than 498 MBs of disk space!

Also - got FDISK to work to make the primary DOS partition to 498 MBs using 512/63/16/1011 - but for some reason from the boot I still can't get the DOSBox Turbo to see "C" after it's been mounted prior to booting from the 622 boot disk image.

Vanilla DOSBox supports at most 504MB images.

Got FDISK to see and set the primary DOS partition to 504 MBs in a new image.

Restarted DOS Box, mounted DOS.IMG as C - had to re-specify disk size - but it mounted it as C: - I then switched to C: and typed boot /sdcard/DOS/622.img - but it still won't let me switch to C: to format. If I go into FDISK it now states no partitions detected and I can't format / switch to C: from the boot disk. Any ideas?

In FDISK when I create the partition it shows up right initially - so not sure what is going wrong.

Partition / Status / Type / Volume Label / Mbytes / System / Usage

C: / 1 / PRI DOS / / 504 / UNKNOWN / 100%
Primary DOS Partition Created

I then proceeded to set the partition as A / Active and reboot

when I go back in
imgmount c /sdcard/dos/DOS.IMG -size 512,63,16,1024
boot /sdcard/dos/622.IMGit does not show any partitions - like all I did was lost.

I also tried a different method I saw in a YouTube video to mount the drives:

imgmount a /sdcard/dos/622.img -t floppy
imgmount c /sdcard/dos/dos.img -t hdd -size 512,63,16,1024
boot -l a

still does not show drive C: from the boot disk.

gulikoza wrote:

Vanilla DOSBox supports at most 504MB images.

Eh? There are 2GB images in Windows 9x DOSBox Guide (Not officially supported) that people have been using successfully for some time now.

If you need to make them from scratch, I think you might need to use IMGMAKE (included in the Megabuild and Daum build, I think), as FDISK will apparently not work on its own.
Patch: Imgmake - creates floppy or harddisk images

It's not the image -

For some reason, FDISK is failing in DOSBox Turbo

I was able to create many 498 -504 MB images successfully with Ubuntu on my phone by using the dd /dev/zero trick - and was able to pull them up in DOS Box just as well as the BXImage created images.

The DOS 6 boot disk FDISK recognized it as the desired size i.e. 498 MBs - but again after FDISK'ing it it would not pull up as C: in the "boot disk" mode, even though before doing the boot option it mounts successfully as C:

I attempted using Ubuntu to fdisk the image - but with the t option set to fat 12/16 - neither option allowed the image to be recognized by dosbox as after doing that DOS Box stated it was no longer a valid image file or something on those lines.

An option I haven't tried is after fdisking in Ubuntu is to format them and makedosfs - problem is on my phone it appears there is no loopback module installed - so that makes that pretty much impossible. I will try this on my desktop Ubuntu installation later on and see if that nets any luck or not, if running FDISK from the boot disk on DOSBox on my linux box does not work.

Just to be clear it sounds to me that after making the partition with fdisk you want to boot of the image. That cannot work. You first have to format it and put a system on it. So, imgmount a floppy with a dos system on it, imgmount the hd image, boot a, format c: /s
See Sample usage of a harddisc image in DOSBOX

Dominus wrote:

Just to be clear it sounds to me that after making the partition with fdisk you want to boot of the image. That cannot work. You first have to format it and put a system on it. So, imgmount a floppy with a dos system on it, imgmount the hd image, boot a, format c: /s
See Sample usage of a harddisc image in DOSBOX

No - trying to boot to A after running FDISK and remounting the image as "C" instead of "2"

First I mount the hard disk .img as "2" and run FDISK from the boot disk, and set the Active partition, then it asks to quit upon exiting FDISK. After re-entering DOSBox Turbo, I then mount the hard disk .img as "C" and run FORMAT from the boot disk, but I am unable to access "C" from the boot disk and FORMAT C: won't work because C: is not available. All this being said, if I attempt to acces C: in DOS Box BEFORE entering the boot /sdcard/dos/622.img command, I am able to access C: and run the dir command but it shows no files and no free space. If I run a FDISK again on after mounting the disk image as C, it does not show any partitions on the image and if I try to partition it a 2nd time I just end up repeating all these steps for the same result.

Why not imgmount as 2 again? Until you used format c: /s on it the image is useless.

Perhaps you should see if what you want to accomplish can be done in ordinary DOSBox first, in case it is a flaw in DOSBox Turbo?

Dominus wrote:

Why not imgmount as 2 again? Until you used format c: /s on it the image is useless.

Because if I try that it states "Must specify drive letter to mount image at."

Jorpho wrote:

Perhaps you should see if what you want to accomplish can be done in ordinary DOSBox first, in case it is a flaw in DOSBox Turbo?

That's my next step - just trying to exhaust my options because I can't put a finger on why the mobile platform should be that much different than standard if it's based off the same base code.

Yup - FDISK works fine in reg. DOS box. Just not in DOS Box Turbo. Got it formatted!

FYI to all whom it may concern - IMGMAKE w/ HAL 9000's build isn't the only way to make 2GB images! Not sure if BX Image can do it too - but using any Linux shell you can do a DD and write zeros to make a blank image - as long as you set it up 512,63,64,1023 in dos box, you're good 2 go!

dd if=/dev/zero of=(path to file) bs=512096c count=40485