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Member Since 11 Apr 2014
Offline Last Active Jul 19 2018 07:07 AM

#9732 Free space and code optimisation in "JSW"

Posted by Spider on 02 July 2018 - 07:04 PM

Would the use of undocumented instructions possibly save a few more bytes, at the potential risk of issues on real machines ? :unsure:


Emulators ( at least as far as I'm aware ) will either cope with undocumented instructions or in some cases via options break into the debugger upon encountering one.


http://www.z80.info/z80undoc.htm perhaps

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#9729 [File] JSW 128 VK.Tap

Posted by Spider on 01 July 2018 - 09:01 PM

This looks excellent. :)


First glance I appreciate the use of the two sprites to indicate the speed factor, and I like the colour cycling effect you have in place on the information page too.


The ramp "patrolling" guardian is also an excellent thought. Almost as though it was originally intended!


Won't add to much more at this stage as I've only had (as I write this) a cursory glance around. :D

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#9672 [File] Jet Set Willy - Turbo Edition

Posted by Spider on 20 June 2018 - 05:08 PM

The increase is appreciated! :)

#9660 [File] Manic Miner - Turbo Edition

Posted by Spider on 19 June 2018 - 08:47 AM

It's up there now, dude.  :thumbsup:




:) I see!


Just tested it (thankfully the older version is still there at the moment!) and its definitely faster, top job! :thumbsup:

#9620 Pokes (non ZX versions)

Posted by Spider on 17 June 2018 - 08:13 AM

Thanks for this, Andy! :)


That's Andy Noble's DOS version, isn't it?

Yes. :) The version that runs on Windows does not appear to accept this code.

#9577 Information for a book needed!

Posted by Spider on 04 June 2018 - 08:57 AM

You're very welcome.


Just say if you need clarification on any of the content I've posted above, I'm happy to try to either re-word it or write it in a different way (if that makes sense) so its possibly more readable.


You may also wish to browse this site too as it contains a lot of information (to put it mildly) http://www.jswcentral.org/ :)

#9574 Information for a book needed!

Posted by Spider on 03 June 2018 - 08:15 PM

Thank you! Your help is invaluable. I have a subsidiary question.


Since it was only possible to complete if the player had first inputted the four POKEs, would they have to input them every time they wanted to play, or could they save the modified version of the game to cassette?

You're very welcome.


Either method really, to keep the changes they would obviously have to save them. :)


If I remember correctly one or more of the Magazine listings gave instructions on how to save the modified code (after the pokes were entered) so they could then save a 'bug fixed ' version if they wished to.


The slight alternative method to having to save the codeblock itself would be to modify the Basic loader and have the pokes in that, that way they would only really have to save said Basic loader as it would patch the game code.


Would a practical example of the latter help perhaps ? Here are two screenshots of the original unmodified loader itself, one from 48K Basic (the coloured one as its got colour token / control codes embedded into it) and one from 128K Basic (which strips them out when viewing) they are identical however, only the viewing method is slightly different, I provided two simply in case you wished to use them you have a choice of one with or without the colour being embedded. To clarify this on a 48K machine or a 128K machine in 48K Basic mode, you would see it as the coloured one, whereas if you viewed/edited it in 128K Basic you would see the non-coloured one. As above they are identical however.


ldr_1.png   ldr_2.png


As can be seen, line 30 loads the game code itself and line 40 executes it so this plenty of space to insert any poke lines as required, such as say:


35 POKE (address) , (value) : POKE (address) , (value) etc etc

#9569 Information for a book needed!

Posted by Spider on 03 June 2018 - 01:41 PM

Hello, good people of the Spectruming world!

I was referred to you by a good chap named Daren at the RZX Archives. I need some help!

I am writing a novel set in the 1980s, which revolves heavily around some kids who play computer games. A pivotal point of the story as a whole involves Jet Set Willy. The way I write it depends upon how you answer my questions. Here goes.

Welcome. :)


Well, others here are probably better equipped to answer your questions however I will (try) to answer them to my best ability for now.


Did Software Projects ever release a bug-free version of Jet Set Willy, or did one have to use the 1984 release with Holman and Else's POKEs in order to complete the game?


No, there was never an 'official' release with the 'four official' Pokes applied as far as I am aware. The re-release by VentaMatic (Spain) retained the bugs unfortunately too. The changes in this version are a different title/scrolly message and the loading message. The room names are the same.

It is however well worth mention here that there were actually two Software Projects releases though, the early one sometimes referred to as 'Pre-Production' had the Manic Miner in-game tune aka "In the hall of the Mountain King" where as the slightly later release had "If I were a Rich Man" as the in-game tune. Apart from this change of 64 bytes, there are very few other changes certainly they appear to be superfluous and possibly just data buffer bytes (updating during play) rather than anything that effects the game itself.

It is also worth bearing in mind you could in theory possibly count JSW2 as a 'bug fixed' version as this originally started life on the Amstrad CPC machines and then was ported across to the Spectrum, both of these machines use a Z80 CPU. There is as a random side note (not relevant to your questions but worth mentioning) an actual JSW1 release for the Amstrad too, although most for this machine are JSW2 aka "Final Frontier"


If Software Projects did re-release it, when did that happen?


Hopefully answered this in my reply above! :)


If the Holman/Else POKEs had to be used on the original, when and where were they printed for players it input?


This is a good question, although they are refereed to usually as "Official Fixes" or suchlike, I remember at the time not really seeing anything other than the odd magazine tip listing with said pokes in, rather than anything from Software Projects themselves. I was not expecting to see a full/half page advertisement ( :D ) stating it but I'd completely wrongly assumed something "official" was printed but it appeared not. I could be wrong here.


Incidentally of the four 'fixes' the one that moves the invisible object from First Landing to The Hall, although it works its not really ideal as said object is still invisible although collected merely by walking over it, in other words if Willy does not jump and just walks (apart from avoiding the arrows) then he will gain this object anyway.


Dumb question: How does one input a POKE on a Spectrum? (It's easy enough on an emulator, but I've no idea how to do it on an actual Speccy.)


This is an open ended question, in summary:

1. On a real machine if the Basic loader is unprotected (as JSW is) it is a simple matter of MERGE'ing it instead of LOADING it (to stop it auto-running) , if you are familiar with the BBC Micro this is quite similar to doing a LOAD vs a CHAIN. Anyway once access to the Basic loader had been gained, said Pokes are just inserted as new lines before the final USR statement which in most cases typically calls the game code.

2. Again on a real machine, if said game was protected then apart from hacking the loader or using a magazine listing, a Multiface device could be used to insert the Poke's once the game had loaded.

3. On an emulator, both of the above actually are possible as Multiface emulation exists although nearly every emulator also has a 'Poke memory' option so its very easy to simply load the game then visit this option in the emulators menu and apply them that way.


4. On an emulator again, the other way on an emulator is by a pre-defined .pok file (most support this) it is merely a tiny text listing of what addresses and what values they should contain, in most cases this means that applying the pokes is then just a drag/drop operation.


Looking forward to your response! All being well, you'll be mentioned in the acknowledgements when the book is completed!


You're very welcome! :)

#9566 Pokes (non ZX versions)

Posted by Spider on 01 June 2018 - 02:30 PM

PC Version.


Note this only appears (at least as far as I can recall!) on the DOS version of this game. The Windows compatible version is not effected unfortunately. The 'DOS' version will run on a 32bit operating system only (or DOS!) whereas the Windows version will run on both 32 and 64 bit systems.


During play carefully press 8 0 2 9 2 6 to get the familiar 'Boot' to appear.


Cavern choice is now possible as it is with the other versions by pressing 6 and a combination of 1 2 3 4 and / or 5


As an extra bonus, once the 'Boot' is there pressing 7 8 and 0 together will enable infinite lives.

#9561 Pokes (Spectrum Version)

Posted by Spider on 22 May 2018 - 01:40 PM

Makes Maria rather less formidable?

Well done. I appreciate the way you phrased your answer too. :) So it does not completely give it away as such.

#9556 Pokes (Spectrum Version)

Posted by Spider on 21 May 2018 - 03:18 PM

Mystery poke for the original game ( ;) ) please do not look it up,  just try to figure out what it has done to the Master Bedroom...


38242 , 0 / #9562 , #00



One for the 16K version of JSW:


26064, 201 = Freeze monsters , not ideal without the immunity poke (here) however.

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#9546 Spot the differences - part two

Posted by Spider on 06 May 2018 - 07:30 PM

After more study, I'm not able to find any other differences, at least nothing that has not already been covered... :)

#9535 Some Manic Miner Remake

Posted by Spider on 05 May 2018 - 01:31 PM

Thanks for the updates Ligan. :)

#9532 Free space and code optimisation in "JSW"

Posted by Spider on 05 May 2018 - 12:51 PM

Well done, Ian, congratulations! :)

I can only concur. :)

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#9425 [File] Manic Miner - Highscore Challenge

Posted by Spider on 17 April 2018 - 12:44 PM

Fresh updates from WOS, particularly from "mzx" :)