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

[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

[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

[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

[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