Pitfall 2's "Display Processor Chip" (DPC)

[Bill Kendrick]

So I remember hearing Pitfall 2 on the VCS/2600 had "an extra chip,"
but it wasn't until today that I hit Wikipedia and learned it was
something David Crane came up with, called the "Display Processor
Chip" (DPC).

Wikipedia simply says: "[it] could greatly enhance the 2600's graphics
capabilities and could process music in 3 channels plus drums. Crane
hoped that the DPC would be used by other game designers to further
extend the life of the aging console, but the video game crash of 1983
made this impossible."

So... what, precisely, did it do?

I just read "Racing the Beam"[*] and then watched a video of PF2
(I sadly don't own it), and aside from the sheer size of the game
and the music, I'm not immediately seeing what the game does that
the 2600 couldn't do out-of-the-box... with the appropriate
software elbow grease.

Another question is: how exactly did a chip on the cart and up
improving the sound and graphics(?) of the system itself.
I admit I'm not a genius when it comes to how cartridges
interact with their host system.

Thanks for any insight or pointers! (There's no DPC article
at Wikipedia!)

[*] An EXCELLENT little book, BTW... and an eye-opener for me, since
I didn't really understand precisely what the VCS's capabilities
were. I now have to go back and take a fresh look at my countless
2600 games to truly understand how amazing they were, under the hood).

--
-bill!
Sent from my computer

[Trevor Holyoak]

Bill Kendrick wrote:

> I just read "Racing the Beam"[*]...

>
> [*] An EXCELLENT little book, BTW... and an eye-opener for me, since
> I didn't really understand precisely what the VCS's capabilities
> were. I now have to go back and take a fresh look at my countless
> 2600 games to truly understand how amazing they were, under the hood).
>

Thanks, I wasn't aware of the book. The reviews on Amazon make it sound
interesting, even if poorly written. I've added it to my wish list.
Maybe I'll drop some hints to my wife for Christmas. ;)

I seem to recall seeing another book that came out in the last few
years, that sounded interesting but I never got around to looking at. It
taught console hardware design, and even had you building something
similar to the VCS. Does that sound familiar to anyone? If so, what was
it called, and was it any good?

Thanks,
Trevor

[Russ Perry Jr.]

bi...@newbreedsoftware.com (Bill Kendrick) wrote:
> So I remember hearing Pitfall 2 on the VCS/2600 had "an extra chip,"
> but it wasn't until today that I hit Wikipedia and learned it was
> something David Crane came up with, called the "Display Processor
> Chip" (DPC).

Not-so-coincidentally, it shares its initials with Mr. Crane
himself. :-)

> Wikipedia simply says: "[it] could greatly enhance the 2600's graphics
> capabilities and could process music in 3 channels plus drums. Crane
> hoped that the DPC would be used by other game designers to further
> extend the life of the aging console, but the video game crash of 1983
> made this impossible."
>
> So... what, precisely, did it do?

I'm not so sure it GREATLY increased the capabilities, but I seem
to recall that it was essentially a sequence generator, and had data
access capabilities that the CPU then didn't have to perform.

Ah, found it. Hopefully this link will work for those interested:

http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&
p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=4644495.PN.&OS=PN/4
644495&RS=PN/4644495

There was some conversation about it on Stellalist, a 2600
programming mailing list, back in Oct 1999, subject "Superchip?",
if you can find it (I haven't looked).

> Another question is: how exactly did a chip on the cart and up
> improving the sound and graphics(?) of the system itself.

By doing things the system either couldn't do efficiently, or
couldn't do at all.

Trevor Holyoak <tre...@holyoak.com> wrote:
> I seem to recall seeing another book that came out in the last few
> years, that sounded interesting but I never got around to looking at. It
> taught console hardware design, and even had you building something
> similar to the VCS. Does that sound familiar to anyone? If so, what was
> it called, and was it any good?

"The Black Art of Video Game Console Design" by Andre LaMothe,
which came with the hardware for the XGameStation. Here's a
link:

http://www.xgamestation.com/view_product.php?id=32

--
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[Bill Kendrick]

Russ Perry Jr. <russp...@sbcglobal.net> wrote:
> bi...@newbreedsoftware.com (Bill Kendrick) wrote:
> > So I remember hearing Pitfall 2 on the VCS/2600 had "an extra chip,"
> > but it wasn't until today that I hit Wikipedia and learned it was
> > something David Crane came up with, called the "Display Processor
> > Chip" (DPC).

> Not-so-coincidentally, it shares its initials with Mr. Crane
> himself. :-)

I figured as much. ;)

> > Wikipedia simply says: "[it] could greatly enhance the 2600's graphics
> > capabilities and could process music in 3 channels plus drums. Crane
> > hoped that the DPC would be used by other game designers to further
> > extend the life of the aging console, but the video game crash of 1983
> > made this impossible."
> >
> > So... what, precisely, did it do?

> I'm not so sure it GREATLY increased the capabilities, but I seem
> to recall that it was essentially a sequence generator, and had data
> access capabilities that the CPU then didn't have to perform.

> Ah, found it. Hopefully this link will work for those interested:

> http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&
> p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=4644495.PN.&OS=PN/4
> 644495&RS=PN/4644495

Oh duh, why didn't I think of looking for a patent? :) Thanks!

> There was some conversation about it on Stellalist, a 2600
> programming mailing list, back in Oct 1999, subject "Superchip?",
> if you can find it (I haven't looked).

> > Another question is: how exactly did a chip on the cart and up
> > improving the sound and graphics(?) of the system itself.

> By doing things the system either couldn't do efficiently, or
> couldn't do at all.

So kind of a co-processor, almost? (It did a bunch of work,
and then the results were accessible as memory addresses.)

Thanks!

[Russ Perry Jr.]

Yeah, though I didn't read through the entire patent, and I'm not
sure it's THAT powerful, but kind of a co-processor, yes. It was
definitely more powerful than simply RAM additions which were
sometimes used (like the CBS RAM-Plus chip).