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SvarDOS / edrdos

Enhanced DR-DOS kernel and command interpreter ported to JWasm and OpenWatcom C
http://svardos.org/
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change dual-file names back to IBMBIO.COM and IBMDOS.COM #114

Open boeckmann opened 2 months ago

boeckmann commented 2 months ago

At least Digital Research DR DOS 6 and Caldera DR-DOS 7.03 kernel files are named IBMBIO.COM and IBMDOS.COM. As the dual-file builds purpose is mainly being a drop-in replacement for this systems, I suggest that the names are changed. Currently they are called DRBIO.SYS and DRDOS.SYS.

As the zero-compressed DRBIO.SYS is smaller than 29K it can be booted at least from a DR-DOS 7.03 bootsector perfectly fine (tested), if renamed to IBMBIO.COM.

ecm-pushbx commented 2 months ago

MS-DOS (IO.SYS / MSDOS.SYS) and IBM PC-DOS (IBMBIO.COM / IBMDOS.COM) boot sector loaders may not work as expected because they may fail to initialise bp to 7C00h, so current SvarDOS flavour EDR-DOS would not find the hidden sectors where expected.

Further, with a kernel file close to the 29 KiB limit the load may fail if you run on a file system with larger cluster sizes such as 2 KiB, all the way up to 32 KiB, 64 KiB, or 128 KiB.

boeckmann commented 2 months ago

I tend to make the single-file kernel the default build, and the dual-file one especially for compatibility with older DR-DOS systems, as I see no benefit in having the dual-file version when not using it with an existing DR DOS. New systems can use the single-file version, like SvarDOS does.

My point of view is that the compatibility outweights the problems with MS-DOS loaders etc. But this is a discussion, so lets see what other opinions show up :)

The DR-DOS provided IBMBIO.COM is 24.810 bytes in size, the EDR one is currently 25.286 bytes. So the EDR kernel should work with the DR-DOS provided loaders where the original kernel does, I guess.