ISA video card w/ a microcontroller.

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Hello,

I spent 8 hours on goole yesterday and 4 hours on google groups .. so
I am pretty sure this answer isn't as quick as a look @ this link.

I am trying to use an ISA VGA card for a text console for a
microcontroller. I want to use the 80x25 mode (I think they startup in
this mode automatically). Does anyone have some extended information
on how to do this? From what I have read I can just write the ASCII
character to the 8 bit data port and strobe, but I don't know anything
about the following bit to be sent (color/inverse video bit) or any
display movement commands, etc.

Thank you,
Charles

Re: ISA video card w/ a microcontroller.
"Charles Douvier" wrote...
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Quite likely the VGA card has it's own BIOS that has to run before the card
behaves like a proper VGA card. That BIOS ROM hold 80x86 instructions...

If you want to program the chip set directly, look for

  Ferraro, R.F. - Programmer's guide to the EGA and VGA cards
  Addison-Wesley

It is old but describes most (older) ISA card chipsets and has driver
sources for them.

Regards,
Arie de Muynck



Re: ISA video card w/ a microcontroller.

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card

Or emulate x86!

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Re: ISA video card w/ a microcontroller.
W.r.t. 80x25 text mode, VGA is functionally
equivalent to CGA and EGA in text mode,
and there should be truckloads of reference
on that.    I'm not sure how to do that on a
non-PC compatible embedded system, but
the easiest (?!) thing is probably writing
directly into the display memory.  If I can find
it, some time ago I wrote a nifty test program
to access video memory.


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Re: ISA video card w/ a microcontroller.

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see  http://instruct1.cit.cornell.edu/courses/ee476/FinalProjects/20 %
http://instruct1.cit.cornell.edu/courses/ee476
http://instruct1.cit.cornell.edu/courses/ee476/video/index.html
for video projects using avr's

Re: ISA video card w/ a microcontroller.
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 VGA cards have Boot-Roms, and part of the PC startup, includes
a call into these, that set all the VGA chip registers.
 To run ISA cards, on a non X86 uC, ( if you can still buy them )
you need to reverse-engineer the BIOS Rom.
 It can be done, but it is 'non trivial' and non portable.

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 We can offer something close :)
 See   http://www.designtools.co.nz/vga_232.htm

This was designed to replace ISA-VGA cards in microcontroller systems.
It runs in 80x25 VGA text mode, (640p x 400p), and has scalable text.
Interface is serial-FIFO, so is uC friendly.

-jg

Re: ISA video card w/ a microcontroller.
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VGA card does not initialize automatically, onboard bios has code for
CPU to initialize it. You can hook the VGA card up to microcontroller
and hardwire most of the address bus, but you still have to take care
of 16-bit data bus, control signals, and initialization code. I've
considered this approach quite a bit and found that it proabably wont
work all that well...


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