DIY Pitfall II cartridge

[SkalTura]

Couldn't find much about it, so I'll ask the question here...

 

If I understand it correctly, there is a custom chip in the original Pitfall II cartridge.
But... would it be possible to make a Pitfall II cartridge with pure hardware (logic chips), so no PLD or other "software" based chips ?

 

Thx!

Edited September 15, 2021 by SkalTura

[+splendidnut]

The DPC chip is essentially a display data processing chip and would require a ton of logic chips to recreate.  It contains 8 self-decrementing data address pointers called data fetchers which allow the user to access it's internal ROM data.  The data fetchers allow the cartridge program (Ex. Pitfall 2) to read the data in numerous ways (rotated, nibble swapped, or masked).  The DPC chip also has the capability of 3 channel music which is done by mixing 3 channels of sound data into a sample stream to be played back thru a single TIA audio channel.

 

Here is a link that summarizes it's capabilities:

https://www.taswegian.com/WoodgrainWizard/tiki-index.php?page=DPC

 

If your goal is to make a DIY cartridge, you will need to use an FPGA chip or something similar (ARM, PIC, etc...) to recreate those capabilities.

[SkalTura]

Okay, so basically not worth the effort...

That's a shame, it's my favorite game to play on the Atari 2600.

 

luckily I still have the original cartridge as well 

 

[bikeguychicago]

Was the DPC used for any other game or just for Pitfall II? 

[+SvOlli]

14 hours ago, SkalTura said:

But... would it be possible to make a Pitfall II cartridge with pure hardware (logic chips), so no PLD or other "software" based chips ?

As already stated, not for a reasonable amount of money / effort. Also: the DPC (chip) should be considered an ASIC.

But the only implementation worth the money is to use a microcontroller based board, like the Melody board, which can be bought at the store here, if you've got an own implementation in mind using the same architecture.

If you just would like to fool around, Harmony or Uno/Plus/etc. will work.

7 hours ago, bikeguychicago said:

Was the DPC used for any other game or just for Pitfall II?

Yes, I remember watching an interview on YouTube, where DPC (David P. Crane) stated, even though the DPC (chip) was intended for generic use, Pitfall II was the only implementation using it.