Hey George,
I have reverse engineered the Video portion of DVI, at least enough to
get 80x25 mode working in VirtualT. I was working on a modern
equivalent called TDock, but discovered I had less than zero time
between work and two young kids. The idea at the time was to build an
expansion board for a RaspPi board with connectors and 5V I/O to
interface with the M100.
I actually built a board at OSHPark, but didn't get it to work before
running into my time crisis (two years ago).
Ken
On 7/25/18 6:40 PM, George Rimakis wrote:
Has anyone managed to reverse engineer this DVI?
That would be a neat project.
~George
On Jul 25, 2018, at 9:30 PM, Randall Kindig <[email protected]
<mailto:[email protected]>> wrote:
Thanks, Brian, that’s very helpful.
Randy
On Jul 25, 2018, at 1:12 AM, Brian White <[email protected]
<mailto:[email protected]>> wrote:
Randy I never answered your last question about the Model 200 cable.
It's these two items:
https://www.amazon.com/gp/aw/d/B003PU1EVG/
https://www.amazon.com/Connector-Rainbow-Ribbon-Cable-1-6ft/dp/B00XP54YKE/
These are just representative examples pulled up quickly from amazon
on my phone. You can get the same things lots of different places
including ebay and digikey etc.
That's it. You just stick the gender changer into one end and stick
that end into the 102 or 200.
For polarity assurance, just keep the cable flat all the way to the
computer.
That's it. No soldering, and the lack of polarity key on the
computer end has an easy answer. And that cable works the same on
both 102 and 200.
I mean it can buch up or fold or loop any way it wants once it's
connected, but just imagine both the DVI and the computer are
sitting on a table, with the back of the computer facing the front
of the DVI, and both boxes are sitting right-side up on their feet.
From that starting position, the cable travels from under the front
of the DVI to the computer without twisting or folding over.
Whichever side of the cable is the bottom at the dvi, is also the
bottom at the computer. If it was a grey cable instead of tha
rainbow one, you could write "bottom" & "top" or "up" & "down" right
on the cable at the computer end with a sharpie, and that would be
enough for even an unsuspecting future owner to get it right safely.
The DVI end is polarity keyed so you don't have to worry about that end.
The only remaining annoyance with that cable is when you pull the
cable out of the computer, the gender-changer pins are just as
likely to stay in the computer as stay on the cable, and then they
are a little difficult to get out of the computer because there is
nothing to get a grip on. So you might want to use a tiny (tiny!)
bit of super glue to keep the pins in the cable. Just enough to
stick the two black plastic parts together, but try to avoid letting
super glue wick and travel down into where the pins make contect
inside the connector on the cable.
Thanks to Mike Stein for the clue about the effect that kind of
straight-through doulble-ended pin header ends up having on the pin
mapping when you use one to butt two female idc plugs up to each
other. It ends up having the same effect as the twists in the normal
cable.
--
bkw
On Tue, Jul 24, 2018, 8:10 PM Randall Kindig
<[email protected] <mailto:[email protected]>> wrote:
I currently have 2. Until a few months ago I didn’t have any
and had never seen a working unit. Now I have 2 great working
units.
I allows the M100/102 to display on a monitor rather than the
small LCD. It also gives it one or 2 disk drives. They are
great, if finicky.
Randy
On Jul 24, 2018, at 7:42 PM, Ken Gregg <[email protected]
<mailto:[email protected]>> wrote:
I see one of these units up for auction on ebay right now:
https://www.ebay.com/itm/Radio-Shack-Tandy-TRS-80-model-100-disk-video-interface/223062580269
On 7/24/2018 12:25 PM, [email protected]
<mailto:[email protected]> wrote:
Oh! Well I've owned my M100 for years now and I had never seen
the DVI. Are these rare? What advantages does this give over a
stock M100 with a floppy drive? I gave a REX in mine, worth
its weight in gold!
Thanks for the replies guys, I still ashamed I didn't know
what DVI was.
Are these rare? Do many on the group have them?
Sent from my iPad
On 24 Jul 2018, at 8:12 pm, Kurt McCullum <[email protected]
<mailto:[email protected]>> wrote:
DVI = Disk Video Interface. It expanded the 100 or 200 with a
180k 5.25" disk drive and an external monitor. Attaches to
the system bus and has it's own DOS.
Kurt
On Tue, Jul 24, 2018, at 12:07 PM, [email protected]
<mailto:[email protected]> wrote:
Perhaps I missed the memo, but I'm not familiar with DVI.
Other than it being a firm video output.
What is DVI in relation to the M100?
