Keypad protection

[Spider]

I was thinking about this the other day.

JSW as we know has the infamous keycode/keypad protection on nearly all variants. If I recall actually the AMS version is harder to read too.

Anyway some releases of MM for other platforms also have the keycode present, these are usually Software Projects or Tynesoft. From memory the MSX and BBC Micro version both had it, although it is just like the ZX version very easily defeated as you can change a simple test for zero or not zero to always pass everything (except the right code)

Question here is, why was the original MM not protected ? I did think that it was because Software Projects used the system on various titles they had and it was not in any way limited on the Spectrum to JSW. There's certainly enough space for it on the Spectrum version of MM.

Unless it was decided when Software Projects released it, there was "little point" in adding it as the Bug-Byte version was already well out and about.

Any thoughts ? My leanings are towards the paragraph just above this, as although its a sort of re-release in a way its not in others and if you look at other games that had protection similar, their re-releases (typically to be fair budget prices though) did not have this.

[Norman Sword]

Tape loading on the cpc 464 for JSW

When a block of data is read from a tape the header block sends a sync byte designating the header and the data sends a different sync byte to designate the data. The header has a sync byte of #2c and the data has a sync byte of #16

For JSW the  sync byte is used to describe the position of the data. So all blocks of data have a differrent sync byte. This allows for bad data blocks to be reloaded, (with a message) and not have to resort to loading the whole tape again.

If I remember correctly the data is also loaded in block by block in reverse order, starting at high memory and loading each block at a lower memory address from the previous block.

Edited October 31, 2021 by Norman Sword
Clarification.

[MtM]

I don't think I have ever seen a version of MM Andy that needed a colour code like the original JSW. I remember Lode Runner,

the Spectrum version I think, needing a colour code, also published by Software Projects (not a bad version either, not as good

as the C64 version mainly down to not being able to manipulate the guards like you could in the C64 version) I can't think of any

other games that needed colour codes - I daresay there is a forum thread about games that had colour codes somewhere

on Spectrum Forums.

[Norman Sword]

My take on the saga.


Chronology for Manic Miner

The game was written for Bug Byte - Bug Byte was licenced to reproduce game and produce Bug Byte specific Manic Miner  art work

Game Modified before Matthews 18th Birthday. To include Software Projects graphics 

Matthew on reaching age 18, becomes a Director Of Software Projects. Licences Software projects to reproduce game and produce Software Projects specific artwork for Manic Miner.

Alan Maton becomes very concerned about software piracy after watching JSW being copied before release. 

JSW has the copycard code inserted.

-----------------------------------

Since the game Manic Miner is not updated to include the copycard and its code. It is not (codewise) revised whilst Matthew is a director of Software projects, and therfore NEVER becomes a game written or part written by Matthew as a director. This Implies that 100% ownership of the game is/was still accredited to Matthew Smith., and was never a part of software projects assets. Continuing - this also implies that Tommy Barton could NOT have bought the asset to clear debts from Software Projects, because it was not owned or part owned by software projects. Thankfully because the copycard code was never inserted into the game.

 

[Spider]

Thanks all for the information. 🙂

The BBC Micro and the MSX (at least) have the KeyPad protection, although most variants floating about now either accept any code or have it bypassed completely. There is a slight thought here that both of those were Software Projects versions, rather than Bug Byte.

Some other titles from S.P do have similar KeyPad protection on the Spectrum, its layout does not exactly match JSW but its the same thing more or less.

 

As a random sidenote the ZX version of JSW2, the original release, the keycode area of code is not compressed much (if at all) and a one-byte change directly to the tape file along with the CRC being tweaked means it will accept any code. I have such a version saved for my own use.