MVT100 the hardware is the serial-to-video part of an ordinary serial
terminal, used as a display output only, no keyboard, one-way
communication from host to screen, no keyboard to host. And just the
electronics, ie instead of having a screen, it has a vga out.
https://bitchin100.com/wiki/index.php?title=VT100
It's a subset of an ordinary serial terminal, so you could do the same
thing with any serial terminal or terminal emulator, except what's
special about it is it renders the M100-specific terminal codes and
maybe uses the font from the Disk/Video Interface (I don't remember).
And in addition to regular rs-232 it also supports a special serial
interface using a hardware mod to the barcode port on a M100 which can
output ttl serial at higher baud rates, and doesn't occupy the regular
serial port uart or the physical port, so the regular serial port on the
100 can be used at the same time as the serial display.
https://bitchin100.com/wiki/index.php?title=BCR_TTL_SERIAL_HACK
The desktop application is a terminal emulator where the terminal it's
emulating is the MVT100 that's all. But since it's display-only, you
still have to use the keyboard on the 100 itself. Like the mvt100, it's
1/2 of a terminal just used as a display.
On the 100, it needs the driver software Steve provides, which works the
same way the Disk/Video Interface does, using the CRT: hooks in the main
rom.
https://bitchin100.com/wiki/index.php?title=Integrated_VT100_driver
I can't find where the rom hooks are documented.
The hand-wavy no-actual-details explanation is the main rom has some
special hook addresses that it will read or jump to at various times,
and those addresses normally just contain a no-op or a return
instruction so they do nothing. The addresses are in ram space, so you
can write to them. So you install some code somewhere in ram, and write
the address to your code into the hook address. Now when the main rom
reads or jumps to that hook, it runs your code instead of doing nothing.
One of those is the CRT: output. The Disk/Video Interface installs some
driver code that makes the CRT: interface actually do something (sends
data over the system bus to the DVI), and adds some functions to BASIC
to use it.
--
bkw
On 3/18/24 20:07, Will Senn wrote:
I'm a little confused about the MVT100...
on this page:
https://bitchin100.com/wiki/index.php?title=MVT100_Desktop_Application
It sounds like it's a terminal emulator for connecting to the M100 over
serial. But somewhere else I saw it as some kind of adapter to talk to
VGA. I'm guessing it's both - adapter gadget provides the VGA out thing
and provides a server for the pc terminal app? I downloaded the software
and it runs fine on linux under wine (to the degree that it appears to
start up and not crash. I couldn't figure out how to get it to talk to
my m100... so I'm guessing I need the hardware gadget in addition to my
rexcpm to get it working?
Thanks,
Will
--
bkw
