Jsw Bbc Computer Version

[jgharston]

I was wondering if you managed to look into making it run properly on the Master series yet ? :) I guess not as I do not see an update although you never know. :)

 

My investigations so far reveal:

(....)

JSW1 , similar to JSW 'tape' corruption although not quite as bad as JSW2, its playable-ish with immunity applied but it looks like the ZX version with the Attic Bug in full swing.

 

The mapping queries over on StarDot prompted me to update my maps, and also to look into getting JSW working on the Master.

 

Not got it perfect yet, but here we are so far: JSW1.ssd.

It no longer crashes, no longer fails to display anything, and the game runs properly. The only problems at the moment are:

* the "special" rooms fail to display any guardians (Bathroom, Top Landing, Bedroom, Nighmare Room)

* the falling Game Over foot is invisible - but still squashes Willy.

 

Almost all the problems stem from JSW1 pointing the VDU driver's line address table to a custom table, but MOS 3 doesn't use a soft line address table, it calculates everything on the fly so you can't make it use a custom table. The only thing the custom table is used for is the text messages, so I modified the code use the standard 40-column text coordinates.

 

I also turned the cursor off, yea gods, that was annoying me.

Edited January 3, 2017 by jgharston

[Spider]

Great stuff, thank you. :)

 

As per my post on 'stardot' I need to check to see if it ran or not on a Compact.

 

I wish I'd kept that machine actually instead of selling it cheaply as apart from no serial upgrade it was about "full" : DFS / Econet / Twin Drives (the correct drive too) , oh well. Probably worth a good few pennies now.

[jgharston]

I've just checked and the patched version works on my Compact exactly the same as the Master, with the same errors that I haven't fixed yet.

[jgharston]

I've gone through the BBC JetSetWilly versions I have and checked them and tidied them up a bit. I'd got a rather confused mess of about five different "versions" that clarified into the three actual versions: JSW1, the cut-down JSW2, and the full JSW2 (which I've distinguished by calling JSW2 and JSWII). Still a couple of bugs to iron out. Also at long last I've got around to updating the maps replacing the Spectrum screenshots with BBC screenshots.
 
http://mdfs.net/Software/JSW/BBC/:

 

Jet Set Willy 1 - Runs on BBC and Master, runs on an active network

• Loader tidied up.
• Flashing cursor turned off.
• Loading screen not overwritten by loading files.
• Patched to run correctly on the Master. Still a few problems, the 'Special' rooms have no guardians and the falling foot is invisible.

Jet Set Willy 2 - Runs on BBC, fails on the Master, fails on an active network

• Loader tidied up.
• Flashing cursor turned off

Jet Set Willy II - Runs on BBC and Master, fails on an active network

• Loader tidied up.
• Flashing cursor turned off.
• If Master doesn't have SRAM banks 4,5,6 free, reverts to loading in parts as on the BBC.

Edited January 6, 2017 by jgharston

[Spider]

That's great. :)

 

I've always (wrongly?) called the two variants of JSW2 as 'tape' and 'disc' , my reasoning was that I'd assumed that the 'cut down' one was available on tape and disc but the full one was disc only.

 

I see on the Master the 'disc' version is happy to load in one long long go, despite only having DFS and filling all the rest of the slots with ram (and chopping the Basic about) I was not able to force feed it into a Model B. No great issue though.

 

I finished my compilation a couple of days ago I just need to whip up a quick menu and then I'll post it here and on startdot too.

[Carlo]

 

Jet Set Willy 1 - Runs on BBC and Master, runs on an active network

• Patched to run correctly on the Master. Still a few problems, the 'Special' rooms have no guardians and the falling foot is invisible.

 

Hi, and thanks for the JSW conversion. I've been trying to convert it for the Master myself, but couldn't get the display straight.

 

I had a go at your version using B-em's debugger and found out the cause for the missing items, although I still haven't come up with a simple solution.

 

The problem is the different text window size (14x1F on a Model B and 14x27 on a Master, according to the pokes you introduced in file JSWL).

Whenever the VDU driver clears the screen, on a VDU 12 command for example, it clears screen memory at 0x3000 to 0x59FF on a Model B, while it additionally clears 0x5A00 to 0x647F on a Master due to the larger text window. This additional area happens to contain definitions for several guardians, as well as the falling foot.

 

Setting the window back to 14x1F wreaks havoc on the Master display of the game. At this point I'm stuck, mainly because I'm ignorant about the video differences between the BBC Micro and the Master. For example, why does a Master require a larger text window in order to display Jet Set Willy correctly? Can you elaborate on this?

 

Thanks,

Carlo.

Edited January 21, 2017 by Carlo

[jgharston]

The problem is the different text window size (14x1F on a Model B and 14x27 on a Master, according to the pokes you introduced in file JSWL).

Whenever the VDU driver clears the screen, on a VDU 12 command for example, it clears screen memory at 0x3000 to 0x59FF on a Model B, while it additionally clears 0x5A00 to 0x647F on a Master due to the larger text window. This additional area happens to contain definitions for several guardians, as well as the falling foot.

Thanks, knowing what is causing the symptoms gives me a way to fix it. I'll have a look when I'm back from work.

 

Setting the window back to 14x1F wreaks havoc on the Master display of the game. At this point I'm stuck, mainly because I'm ignorant about the video differences between the BBC Micro and the Master. For example, why does a Master require a larger text window in order to display Jet Set Willy correctly? Can you elaborate on this?

It's because the BBC uses a software characters-per-line table and JSW sets up a 32-characters-per-line tables and tells the VDU drivers to use it. The Master calculates the characters-per-line on the fly and is fixed at 20,40,80, so the patch makes JSW align it's 32-chars-per-line display within this fixed 40-char window.

[jgharston]

Bingo! Carlo set me looking in the right direction.
Jet Set Willy 1 for the BBC
Now runs fully on the Master.

[Spider]

Bingo! Carlo set me looking in the right direction.

Jet Set Willy 1 for the BBC

Now runs fully on the Master.

 

Great :)

[jgharston]

Spoke too soon, as the game progresses those sprites gradually get eaten. Go into the Nightmare room, leave it, then go back in again. ;)

I think I know where the problem is.