DOS ain't dead

MODE command (Developers)

posted by kerravon, Ligao, Free World North, 16.10.2021, 02:07

> > MODE can do an OS call and the OS can keep
> > track of the situation. I assumed that is
> > how it was done in MSDOS too, but maybe not.
>
> I'm not sure how MS or Free or any other DOS actually does it. But I think
> if I were implementing it I would just read the UART data directly from the
> I/O port. Even though there's not a standard BIOS (INT 14h) call you can
> use, the base I/O addresses of the four serial ports are stored in the BIOS
> Data Area (BDA) at 0040:0000 so they are part of the BIOS. It odes seem
> weird that there isn't an INT 14h call to read the current status, almost
> as if they expect you to use direct I/O.
>
> I've only messed around with serial ports a little bit, and when I did I
> always used direct I/O. I wrote a TSR called SERIAL that monitors the
> status of a serial port in "real time" on the screen, which you can
> download from my website (bretjohnson.us) if you're interested. I also
> know in the old days at least some of the BBS's used FOSSIL, which is an
> "upgraded" INT 14h, but that won't help you here.

PDOS/386 uses the BIOS for everything, which gives
it a benefit that a BIOS vendor can implement the
serial port on INT 14H as some other device, like
Bluetooth or Wifi.

My dumb phone (an Alcatel Onetouch) supports Bluetooth
plus has an internet connection, and it would be great
if I could boot PDOS/386 on the metal, point my BIOS to
my phone, and be able to contact a newsgroup. I was
hoping that SeaBIOS could help with that, but the
bottleneck is apparently Bluetooth being undocumented.

The next best thing is for me to buy a computer with a
real serial port, and connect that to another computer
running Linux or whatever and presenting me with the
newsgroup capability by forwarding on my requests.

Or simply continue as now which is to run PDOS/386
under Bochs or qemu or Virtualbox under Windows.

BFN. Paul.

Complete thread:

• MODE command - kerravon, 14.10.2021, 12:34 (Developers)
  • MODE command - bretjohn, 14.10.2021, 17:36
    • MODE command - kerravon, 15.10.2021, 00:29
      • MODE command - bretjohn, 15.10.2021, 07:29
        • MODE command - kerravon, 15.10.2021, 07:42
          • MODE command - bretjohn, 16.10.2021, 00:50
            • MODE command - kerravon, 16.10.2021, 02:07
              • MODE command - RayeR, 18.10.2021, 21:44
  • MODE command - DosWorld, 22.10.2021, 03:35
    • MODE command - kerravon, 23.10.2021, 01:50
      • MODE command - DosWorld, 01.11.2021, 19:05
        • MODE command - kerravon, 01.11.2021, 20:02
          • MODE command - tom, 02.11.2021, 18:53
            • MODE command - kerravon, 02.11.2021, 21:22