Can an Amiga write MS-DOS disks from an image?

[motorollin]

I'm thinking of trying to get PC-Task up and running, simply because I have never tried it on anything faster than an 040. I don't have a PC I can use to create a DOS boot disk. Is there any way I can download a boot disk, e.g. from bootdisk.com, and use my Amiga to transfer the image on to a real floppy for use in PC Task? I am of course aware of tools which write disk images to floppy on the Amiga, just not sure if they can be used in this way with an MS-DOS image.

--
moto

[amigagr]

maybe it's posible with the use of fat95 and the filedisk.device. modify the MS0: drive to use the filedisk.device and not the mfm.device and try.
at least it will mount the dos image.
give a feadback if it works :-)

-edit-
or modify the mountiso driver and try.

[motorollin]

I don't think mounting the image is the answer. After all you don't mount an ADF before writing it to a disk. I just want to dump the raw contents of the file on to the disk, regardless of filesystem. I would imagine this is possible, since the Amiga doesn't have to understand what's in the image in order to write the tracks to floppy (I assume). Also, it's a 1.44MB image. I think the floppy drive in my A4000 is HD, so it should be ok - as long as the software doesn't stop after 720/880k.

I'll just try it and report back :-)

--
moto

[motorollin]

Just tried ADFBlitzer and I don't think it wrote the whole disk - I counted only 40 clicks from the drive and then it stopped. I then tried the Amiga port of dd to pipe the raw file directly on to the disk, but this failed with an "unspecified error" after about 500 bytes :-?

[EDIT]
Anybody know if it is enough to format PC0, then put command.com etc on to it, from the Amiga side? Will that boot under PC Task?
[/EDIT]

--
moto

[uncharted]

There was, IIRC, a specific flag you needed set in MS-DOS format to create a boot disk (I think it was /S).  It's been rather a long time since I last had to play with DOS floppies though.

[marcfrick2112]

Hi Moto:

Well not sure if this can help, but DMS WB V. 3.05, supposedly handles HD and PC floppies... (Either try Aminet, or I could E-Mail it to you...)

Can't try it out personally, only DD dirves here

[motorollin]

@Andy
Yes, it's /s. But doesn't that just copy command.com et al so the disk will boot? Not sure whether it does anything to the bootblock of the disk itself to make it bootable (i.e. with AmigaDOS "install" command).


@MarcFrick
Just had a look on Aminet for that version and can't find it. Could you let me know where you got it?


This may all be academic now since I don't seem to have PC Task on my Amiga any more, and I think my CUCD with PC Task on it is long gone :-(

--
moto

[Trev]

Just a quick observation: Everyone screams murder at the first sign of Amiga piracy, but an open discussion of pirating MS-DOS goes unchecked. Silliness.

Anyhow, MS-DOS bootable disks consist of the following:

1. FAT file system (type depends on type and size of media)
2. boot sector
3. IO.SYS (or IBMBIO.COM or equivilent)
4. MSDOS.SYS (or IBMDOS.COM or equivilent)
5. DRVSPACE.BIN or DBLSPACE.BIN (if required for disk compression)
6. COMMAND.COM (or other shell, as specified in CONFIG.SYS)

You can safely remove DRVSPACE.BIN or DBLSPACE.BIN if you're not using compressed disks. Note that later versions of Stacker and similar products named themselves DRVSPACE.BIN or DBLSPACE.BIN to take advantage of the early loading mechanism and install their own compression APIs.

The FORMAT and FDISK /MBR commands update the boot sector.

The FORMAT /S and SYS commands copy the appropriate system files to the disk.

EDIT

Anybody know if it is enough to format PC0, then put command.com etc on to it, from the Amiga side? Will that boot under PC Task?

Disks formatted by CrossDOS under Amiga OS 3.x are not bootable. The boot sector just displays a message and enters an infinite loop:

Code: [Select]


        sti                             ;enable interrupts
        xor ax,ax                       ;ax = 0000
        mov ss,ax                       ;ss = 0000
        mov ds,ax                       ;ds = 0000
        mov sp,0x7c00                   ;ss:sp = 0000:7c00
        mov si,0x7c59                   ;ds:si = 0000:7c59
        mov ah,0xe                      ;ax = 000e (BIOS video output)
        mov bx,0x7                      ;bx = 0007 (grey on black)
getc:
        lodsb                           ;al = ds:[di], inc di
        test al,al                      ;al = 0?
loop:
        jz loop                         ;yes, loop forever
        int 0x10                        ;display character
        jmp short getc                  ;get next character
msg:                                    ;0000:7c59
        db "CrossDOS(TM) non-bootable disk!",0


Trev

[motorollin]

Trev wrote:
Just a quick observation: Everyone screams murder at the first sign of Amiga piracy, but an open discussion of pirating MS-DOS goes unchecked. Silliness.

Where did that happen? Who mentioned pirating MS-DOS?

Trev wrote:
Anyhow, MS-DOS bootable disks consist of the following:

The problem is I have no way of creating the disk from within a DOS environment since I don't have a PC with a floppy drive. That's why I was trying to write the disk image from bootdisk.com directly to a floppy with my Amiga.

--
moto

[Trev]

Where did that happen? Who mentioned pirating MS-DOS?

None of the images on bootdisk.com are legal. ;-) FreeDOS is an excellent substitute, but it's not truly 100% MS-DOS/PC-DOS compatible.

The problem is I have no way of creating the disk from within a DOS environment since I don't have a PC with a floppy drive. That's why I was trying to write the disk image from bootdisk.com directly to a floppy with my Amiga.

Unfortunately, owning a copy of Windows doesn't entitle the end user to an unlimited number of installed copies of MS-DOS; however, no one's going to hunt you down for tinkering with MS-DOS.

I do recommend trying FreeDOS; however, it may not work properly under PC-Task. Try searching for PC-Task in the forums here. Quite a bit of discussion has gone on in the past regarding PC-Task, making bootable floppies, etc.

Trev

[motorollin]

Trev wrote:
None of the images on bootdisk.com are legal. ;-) FreeDOS is an excellent substitute, but it's not truly 100% MS-DOS/PC-DOS compatible.

Really? I didn't realise that. Although didn't MS give DOS away at one point anyway?

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moto

[Trev]

Really? I didn't realise that. Although didn't MS give DOS away at one point anyway?

In the same way that most Amiga software is perceived as free or abandoned? No, and Microsoft is still quite vocal about protecting their aging intellectual property, hence the noise around the FAT file system over the last few years. (FAT is the de facto standard file system for flash devices and FAT32 is part of the EFI specification.)

Trev

[motorollin]

Trev wrote:
In the same way that most Amiga software is perceived as free or abandoned?

No, I thought MS actually allowed people to download it. Maybe I'm thinking of Apple with System 7.

--
moto

[Trev]

Probably. Caldera open sourced DR-DOS as OpenDOS at one point but quickly changed their minds. You can still find source and binaries for OpenDOS 7.01, although neither The SCO Group (Caldera) nor DRDOS, Inc. (the current owners of DR-DOS) support it. Apple does have a nice archived and unsupported software section. So do Borland and Novell.

MS-DOS is so easy to come by, even on Microsoft's own web site, that it would be very difficult for Microsoft to actively seek out and prosecute everyone using it. Of course, everyone thought the same thing about file sharing and the MPAA and RIAA. ;-) WinPE (and various free alternatives) have changed the landscape a bit, but as most everyone knows, MS-DOS boot disks were once an indispensable support and installation tool.

So, your free alternatives are OpenDOS, FreeDOS, and perhaps a few others.

Trev

[rkauer]

 I personally don't care about M$ (those Bills outside can kill each other and we'll have a better world, IMHO).

 Back to the question: in what format the image is?

 A good trick: mount a RAD: device, with the geometry of a regular M$ floppy and cast the image in there, if you have a standard (to Amiga) format.

 .img is not a valid format to Amiga, I have to say.

 .exe or .com too...

 But if the image is in ISO format, go for it! Use mountISO (or ISOmount, don't remember now) from aminet.