Copy Protection in 'Jet Set Willy': developing methodology for retrogame archaeology

[Spider]

9 hours ago, Jet Set Willie said:

Some colours from the colour code sheet and password screen didn´t match with the original MSX tape. I don´t mean that there´s an error in some parts of the sheet, as by typing in "wrong" colours the password screen let me play the game. The colours and numbers on password screen may have been in wrong order, I think.

I'd have to look but I think most MSX versions would of had a "enter any code you like" type of fix as its one byte only usually to do this. I've not seen (lately) the MSX codesheet so I cannot be sure, I do remember Manic Miner MSX had a sheet though too, and so did the BBC Micro version.

[Norman Sword]

Colour codes for the spectrum JSW and jSW2 are formed from a block of data - If I recollect correctly I copied the data from the Amstrad CPC version - in order to arrive at the data for JSWII---- (not checked if it ended up with the same colour codes)

The data for the MSX version of JSWII would probably do the same thing - a block of data to generate the codes. It would make life very difficult for the coder, if the data was anything but fixed. E.g. to use the game data/code, means every edit of the game would change the colour codes ---

Enclosed is the MSX colour code for JSWII (1st picture) - NOTE it is NOT the same as the zx spectrum codes for JSWII.(2nd picture)

 

Edited September 17 by Norman Sword

[Norman Sword]

Curiosity - was the CPC data sheet for the final frontier the same as the zx spectrum data sheet for JSW2. I could not find the sheet easily so I just took a quick photograph - whilst the photographs are not really good enough for usage - they are however good enough to answer my own question - Was the colour code the same. Answer NO.

Edited September 17 by Norman Sword

[Spider]

I never got around (sorry) to actually comparing them. I don't currently own the original JSW2FF Spectrum release***

I had assumed they were the same because unlike other Software Project games that use the 'keypad' type code, the colours for the Spectrum and Amstrad versions were the same (colours) aka:

Blue / Red / Yellow / Green (CPC)

Blue / Red / Green / Yellow (ZX)

Ocurred to me the reason for the slight difference is because the CPC has them slightly differently ordered:

Blue/Yellow/Green/Red (Pen value and keys 1,2,3,4)

Blue/Red/Green/Yellow (Ink value and keys 1,2,4,6)

Sorry for the truncated picture but I wanted to see them side by side, I don't have any decent tools installed currently:

 

*** I do have it somewhere I thought in my clearout I'd find it but alas no.