There's a couple of problems. For one, Peter Hizalev's version of the board
uses a higher model of PIC and I'm not sure if the one used in the MVT100
design is up to the task (Stephen and I had discussed going down this path at
some point). I just tried flashing Peter's .hex file into my MVT100 and that
was a no-go - the LED didn't illuminate and no video output was produced. (I
tried v3.0.2 and v2.0.2 whose file size was more in line with the .hex file for
this version of the board, but both produced the same non-result.)
I really don't know enough about these devices or the MPLAB toolkit to say what
would be involved in compiling Peter's source to run on this PIC, not to
mention whether it has the resources to run Peter's code. On top of that, his
version of the board doesn't have composite video output or baud rate jumpers,
so those features would be lost unless someone with more skills than I have put
that code back. Not to mention, the M100 extra escape codes would need to be
added and the 128-255 characters from the M100/DVI character set would need to
be converted.
It's probably not impossible, but it's definitely not a task I'm cut out for.
:)
I think the improvements I'm making will help quite a bit. The original Geoff
Graham design used a 6x12 font which was actually 5x10 if you subtract buffer
space. Of that, most characters only occupied 5x7 pixels and the rest was
reserved for descenders and buffer space. Then, in 24-line mode it would scale
up to 6x18 by simply repeating every other scanline. This made a bit of a mess
of the characters, which I'm guessing had led Geoff to some compromises in the
character shapes to minimize the negative side-effect of the scaling.
I'm re-drawing the characters as 6x18 (while still retaining the 6x12 character
bitmaps for the code to use in 36-line mode) so a normal capital letter would
occupy 5x11 pixels with up to 4 pixels available for descenders. I was
hand-scaling the original Geoff Graham character shapes (except for my improved
6, 9, and Q) but then had the idea to look at the real DVI font to see if it
has more pleasing character shapes. At the very least, it's more authentic to
the MVT100's purpose. :)
(Note: if the DVI characters are horrible, I may just stick with Geoff's
characters. In all likelihood, I will probably end up with two full character
sets, and in that case I guess people could choose to burn a .hex file with the
DVI-inspired font or the Geoff-inspired font...)
jim
From: M100 [mailto:[email protected]] On Behalf Of Mike Stein
Sent: Wednesday, January 27, 2021 12:53
To: [email protected]
Subject: Re: [M100] DVI character set
CAUTION External Sender: Do not click links or open attachments unless you
recognize the sender and know the content is safe.
Just thought since all the source files are there it might be helpful if you're
also changing the MVT character set.
On Wed, Jan 27, 2021 at 2:25 PM Stephen Adolph
<[email protected]<mailto:[email protected]>> wrote:
thanks Mike, similar motivations for sure. The other part of it is that the
M100 DVI character set is unique and related to the M100. So, thinking to both
improve it and change the character set to "M100 style".
On Wed, Jan 27, 2021 at 2:21 PM Mike Stein
<[email protected]<mailto:[email protected]>> wrote:
https://github.com/petrohi/terminal/tree/master/firmware/Terminal.X<https://can01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgithub.com%2Fpetrohi%2Fterminal%2Ftree%2Fmaster%2Ffirmware%2FTerminal.X&data=04%7C01%7CJim.Anderson%40kpu.ca%7C87a9dab7855f472c06be08d8c3059ece%7C66b9f62d3042495eaab6db86f21500c0%7C0%7C0%7C637473776195987532%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=HRdKEMW9C46NhL10V2dKM%2BWOeXPTEd%2BnHiT8wDF7Sg8%3D&reserved=0>
"The updated Version 2 is a huge improvement to the display and character
generation. It results in an easier to read and much clearer display. "
On Wed, Jan 27, 2021 at 1:05 PM Stephen Adolph
<[email protected]<mailto:[email protected]>> wrote:
looks like 8x8 characters, 2KB total.
On Wed, Jan 27, 2021 at 12:00 PM Stephen Adolph
<[email protected]<mailto:[email protected]>> wrote:
super cool thanks for the quick turn!
Steve
On Wed, Jan 27, 2021 at 11:52 AM Brian K. White
<[email protected]<mailto:[email protected]>> wrote:
On 1/26/21 10:42 PM, Stephen Adolph wrote:
> Hey DVI owners,
>
> Would someone mind doing a bit if information mining?
>
> I would love to get the font bitmap for the DVI. Jim Anderson is
> working on improvements to MVT100 firmware and it would be cool to copy
> and use these fonts.
>
> It is stored in a 4 K eprom M17. So I am wondering if someone could
> pull the chip and read the eprom data?
>
> Thanks
> Steve
>
Here ya go
https://drive.google.com/drive/folders/1yqVh_mj5vtBJhYng-Uitvsjnykq0Knnt?usp=sharing<https://can01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fdrive.google.com%2Fdrive%2Ffolders%2F1yqVh_mj5vtBJhYng-Uitvsjnykq0Knnt%3Fusp%3Dsharing&data=04%7C01%7CJim.Anderson%40kpu.ca%7C87a9dab7855f472c06be08d8c3059ece%7C66b9f62d3042495eaab6db86f21500c0%7C0%7C0%7C637473776195997520%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=mlFvo8%2FaD1i88l0lX%2BWw%2FB2uFVkxd5HCoe04wp5Cx0U%3D&reserved=0>
I have 2 units and dumped them both and they were identical.
M40 is labelled "P" (program?)
M17 is labelled "CG" (character generator?)
--
bkw
