On-Chain Art

Today's http://onchainchecker.xyz listing is a special one in many ways:

PETARP by the late @nopsta 

PETARP is the precessor of much more popular collection ORAAND. Although not fully on-chain like ORAAND, PETARP stores the executable Commodore 64 programs on-chain

writing onchain programs for the Commodore 64

1/

In PETARP, the artwork is accessible from the chain through getTokenPRG calls. With parameter unmodified=false, the returned binary corresponds to art as seen on marketplaces

Cryptoartist focusing on dynamic and fully on-chain artworks.

2/

The binary is composed from 3 layers

The base layer of the binary is basePRGData that contains the template of the PETARP Commodore 64 program

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On top of that, each token has a set of token-specific parameters that are retrieved through getTokenParams call. These parameters are applied on top of base PRG file to alter the program to be unique for that particular token

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The binary data returned from getTokenPRG can be converted easily into a binary program for instance with a simple bash command combo:

echo "0x01080b...00" | xxd -r -p > petarp.prg

This file can then be executed in any C64 emulator or even real hardware!

6/

Although PETARP utilizes off-chain emulator, nopsta also managed to deploy on-chain version of his emulator to Ethereum as part of ORAAND. Demonstrating it would be possible to write a wrapper that makes also PETARP tokens fully on-chain!

https://etherscan.io/address/0x40307D57da1BEdF31967dC9fa186c1026b496AB2#code

7/

Given that PETARP tokens depends on centralized server (http://nopsta.com), the tokens are rated as 3/5 by On-Chain Checker. Although the core program is fully on-chain, marketplaces and dapps depend on http://nopsta.com being online if no wrapper is created

8/  In short term, the best that could be done was to launch a preservation effort. For the eventual case of nopsta.com going offline, @0xfff started an archival project I also contributed to, available at:

8/  In short term, the best that could be done was to launch a preservation effort. For the eventual case of nopsta.com going offline, @0xfff started an archival project I also contributed to, available at:

https://github.com/0xfffxfff/nopsta

9/ Finally:

PETARP is an interesting artwork from nopsta. It can be treated as a prototype for many of the technical feats also seen in ORAAND. Its not fully on-chain, but is on-chain in Commodore 64 executable PRG format.

And hence, deserve to be On-Chain Checker listed