The TI 34010

From: Derek Peschel <dpeschel_at_u.washington.edu>
Date: Fri Mar 5 22:58:42 1999

Eric Smith wrote:
> Derek wrote:
> > Exactly why isn't it VGA-compatible?
>
> The 34010 isn't even *similar* to a VGA. The exact extent of the
> compatability is that both hook up to a host processor, and both produce
> a video output.
>
> > I thought that certain things are true of the 34010:
> > - flexible memory architecture
>
> If a large flat address space is a "flexible memory architecture",
> then the 34010 certainly has it. However, that isn't what VGA uses. VGA
> has all sorts of crufty bank switching and other disgusting hacks.

I should have used a different phrase. Isn't it possible to have the 34010
interpret the data in (data) memory in various ways, based on the code you
put in (code) memory? That's what I meant by "flexible".

> > - many operations done in software (not hardware)
>
> Actually most of the interesting operations of the 34010 are done in
> microcode. But those operations aren't similar to VGA.

Again, I was thinking of the reconfigurability of the 34010.

> > It's certainly possible to emulate the Hercules, CGA, and MDA. Is there
> > some lack of configuration registers, or some internal timing constraint,
> > that makes emuilating the VGA impossible?
>
> The 34010 doesn't have any built-in support for emulating any of those things.
> Sure, you could do it by adding a big pile of external logic (which you could
> put into an ASIC, or some PLDs). Due to communication overhead, it would
> be a fair bit slower to emulate a VGA with a 34010.

Ah. Well, there goes my idea of havng an "uber-graphics board" that does
everything... As for emulating the older cards, I have a _Micro Cornucopia_
issue which describes a board that promises exactly that. There's some
external logic, but I doubt there are any ASICs.

> It's cheaper and easier to just put a VGA controller on the card, since that
> does exactly what you need in a single inexpensive chip. Leave the 34010
> to doing what it does well. For example, acting as a display list processor
> for AutoCAD. The VGA interface is too low-level and baroque to be
> efficiently emulated in software.

Hmph. I should have guessed. You might have already figured out that I'm
always thinking of the design of my Perfect Computer (tm). The problem is:
The IBM PC has software, the Perfect Computer doesn't. I'd either have to
write all the software myself, port it from the IBM -- but the point was
to *avoid* all the cruftiness of the IBM -- or write a PC emulator. Ick.
Of course I could get the software from somewhere else.

Also, I fear that any design I could come up with will never be as fast as
any current PowerPC or Intel systems. Those hacks do serve a purpose!
Unfortunately, PC software is successful *in spite of* the nature of the PC,
not *because* of it. :(

What are the chances of successfully emulating EGA?

-- Derek
Received on Fri Mar 05 1999 - 22:58:42 GMT