Hello all,

Dusk's design goal is broadly the same as Collapse OS, that is, run on as many
machines as possible, including partially broken ones. Collapse OS targets 8-bit
and 16-bit, Dusk targets the rest.

I've been thinking of a scenario where Dusk could shine: old partial PCs. For
example, I have in my stuff an old motherboard with a Celeron and some RAM on
it, but no graphic card that fits it. The BIOS won't let me boot it to serial
port.

Unless there's a magic trick I don't know about to make BIOS boot to COM1, this
hardware is unusable. But it's not broken! I *should* be able to use that
hardware.

I've been thinking that maybe I could pop the BIOS ROM out and replace it with
some kind of EEPROM, handle initialization myself, directly. Maybe it's a lot
more complicated than I think, but maybe it's not. Maybe it's as trivial as
starting to poke COM1 ports.

If Dusk meets its design goals, it should be an ideal companion to this kind of
experiment.

Regards,
Virgil

On August 2, 2022 3:10:35 p.m. EDT, Virgil . > Maybe it's a lot
>more complicated than I think, but maybe it's not. Maybe it's as trivial as
>starting to poke COM1 ports.

Modifying or writing new bios sounds too hard and very system specific.

I think you're on the right track to poke PC serial console at the standard locations (io port 0x3f8 and similar) in DuskOS by default.

Any bios boot restrictions could be bypassed by shorting/removing the CMOS battery (old systems) or selectively erasing flash blocks w/ external programmer (for newer systems, collapse OS flash programmer ought to be a fun exercise).

Then boot DuskOS via USB, CD rom, network or whatever the default bios config allows (usually a lot).

No access to bios configuration, but working serial console on nearly all PCs.

S

>If Dusk meets its design goals, it should be an ideal companion to this kind of
>experiment.

Cool stuff.

S


-- 
Shawn Nock <shawn@provisoire.ca>

Old PCs used to do a POST check scan at a memory range where the BIOS
existed but also a few addresses spaces nearby. If a CRC check of
these groups came back as zero then it would execute that ROM. One of
my first ever "embedded" apps was writing a ROM that you could plug
into the IBM PC that then gave access over to a specialized NEC V-20
board my employer created to do external controls for some automation
equipment. Was a great project and basically used the PC as a
terminal. There's no free ROM socket any more like there used to be
but if the POST sequence still works the same you might be able to
make a plugin board (or fake something in an emulator) that could get
executed during boot time. Machine would be in initial segmented mode
still which you could change as you like. Have no idea what the new
BIOSes do these days and all this SecureBoot and UEFI nonsense really
just gums up the works, IMHO. Good luck!

  -- Ben Scherrey


On Wed, Aug 3, 2022 at 2:11 AM Virgil Dupras <hsoft@hardcoded.net> wrote:
>
> Hello all,
>
> Dusk's design goal is broadly the same as Collapse OS, that is, run on as many
> machines as possible, including partially broken ones. Collapse OS targets 8-bit
> and 16-bit, Dusk targets the rest.
>
> I've been thinking of a scenario where Dusk could shine: old partial PCs. For
> example, I have in my stuff an old motherboard with a Celeron and some RAM on
> it, but no graphic card that fits it. The BIOS won't let me boot it to serial
> port.
>
> Unless there's a magic trick I don't know about to make BIOS boot to COM1, this
> hardware is unusable. But it's not broken! I *should* be able to use that
> hardware.
>
> I've been thinking that maybe I could pop the BIOS ROM out and replace it with
> some kind of EEPROM, handle initialization myself, directly. Maybe it's a lot
> more complicated than I think, but maybe it's not. Maybe it's as trivial as
> starting to poke COM1 ports.
>
> If Dusk meets its design goals, it should be an ideal companion to this kind of
> experiment.
>
> Regards,
> Virgil