DOS ain't dead - BIOSCOM - use a serial terminal as a text-mode display

samwdpckr

08.09.2024, 01:44

BIOSCOM - use a serial terminal as a text-mode display (Announce)

I have one XT-class computer with an MDA graphics card, but I don't have a display for it. It does have serial ports, so I wrote this program so that I can actually use that computer for something.

The program can be downloaded from here:
http://sininenankka.dy.fi/leetos/software.php

I also recorded a video of using the computer with PuTTy as its screen: https://www.youtube.com/watch?v=w9IM43iaVUE

mceric

Germany,
08.09.2024, 14:36

@ samwdpckr

BIOSCOM - use a serial terminal as a text-mode display

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> I have one XT-class computer with an MDA graphics card, but I don't have a
> display for it. It does have serial ports, so I wrote this program so that
> I can actually use that computer for something.
>
> The program can be downloaded from here:
> http://sininenankka.dy.fi/leetos/software.php
>
> I also recorded a video of using the computer with PuTTy as its screen:
> https://www.youtube.com/watch?v=w9IM43iaVUE

that seems to be rather slow, looking at the video, maybe it will help to tune how it deals with scrolling?

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FreeDOS / DOSEMU2 / ...

samwdpckr

09.09.2024, 00:03

@ mceric

BIOSCOM - use a serial terminal as a text-mode display

Post reply

> > I have one XT-class computer with an MDA graphics card, but I don't have
> a
> > display for it. It does have serial ports, so I wrote this program so
> that
> > I can actually use that computer for something.
> >
> > The program can be downloaded from here:
> > http://sininenankka.dy.fi/leetos/software.php
> >
> > I also recorded a video of using the computer with PuTTy as its screen:
> > https://www.youtube.com/watch?v=w9IM43iaVUE
>
> that seems to be rather slow, looking at the video, maybe it will help to
> tune how it deals with scrolling?

It detects situations where the screen has been scrolled down, but it can only do so much. If the screen has been scrolled more before the last lines have been updated, it starts updating the screen line-by-line, because it has only one double buffer in the memory. A better scrolling detection would require two double buffers. Each buffer is 4K in the standard 80x25 text mode.

The baud rate on the video is 19200, which is the maximum that VT420 can do.

bocke

10.11.2024, 10:13

@ samwdpckr

BIOSCOM - use a serial terminal as a text-mode display

Post reply

> I have one XT-class computer with an MDA graphics card, but I don't have a
> display for it. It does have serial ports, so I wrote this program so that
> I can actually use that computer for something.
>
> The program can be downloaded from here:
> http://sininenankka.dy.fi/leetos/software.php
>
> I also recorded a video of using the computer with PuTTy as its screen:
> https://www.youtube.com/watch?v=w9IM43iaVUE

You might also want to check out CTTY command:

https://www.youtube.com/watch?v=wqbFyMBUIe4

https://www.youtube.com/watch?v=NWHiPGP0r6k

Although, this will work only with programs that use MS-DOS I/O functions without calling the BIOS functions (like triggering video and keyboard interrupts directly).

DosWorld

10.11.2024, 11:32

@ samwdpckr

BIOSCOM - use a serial terminal as a text-mode display

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https://www.serdashop.com/MCE2VGA

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Make DOS great again!

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