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Member Since 23 Aug 2015
Offline Last Active May 25 2019 01:35 PM

#11071 [File] Jet Set Mini

Posted by IRF on 25 May 2019 - 09:04 AM

Is anyone "seeing red" in frustration over this yet?

#11069 [File] Jet Set Willy: Mono

Posted by IRF on 23 May 2019 - 11:22 AM

Having refreshed my memory, the flaw doesn't work in the way that I outlined in my previous post.  The items jiggle up from their default position, not down (as I had misremembered).


If you have an item in the top cell-row, then it discolours the cell in the bottom cell-row directly below it.  (The top graphic byte of the item is interpreted as an attribute byte, overwriting the primary attribute buffer.)


This is normally disguised, because in Mono mode, everything is overwritten in black-and-white anyway, even though technically all the room blocks remain retain their colour attributes (upon which Willy's interaction with them is based).


So it's normally a harmless effect (an 'invisible visual glitch'!)  But if the top pixel-row of an item's graphic definition matches the attribute byte of a defined room block type, then other effects can occur.


In the attached test file, I have defined an item shape in West Wing and added some items in the top and bottom cell-rows.  There is no collision with the vertical guardian, as I had initially expected, but there are a couple of effects:


(1) If you try to walk down to the bottom of the ramp, you will notice that Willy is killed for no apparent reason.  The item's top pixel-row is entirely filled in - all eight pixels are on; it holds the value #FF - this matches the defined attribute byte for Fire cells, so there are two invisible Fire cells created in the bottom cell-row;


(2) The bottom two items disappear after two time-frames - because the #FF Fire cells hold white INK, collecting the items.  (The slight time delay occurs as the secondary buffers take a while to catch up with the corruption of the primary buffers.)

Attached Files

#11068 [File] Jet Set Willy: Mono

Posted by IRF on 23 May 2019 - 10:39 AM

I seem to recall that I identified a flaw with the Jiggle patch, which causes the bottom pixel-row of the graphic of an item located in the bottom cell-row of the screen, to spill over into the top pixel-row of the top cell-row on the screen, causing a permanent overwriting of that graphic byte.  Such graphical corruption would be prone to collision with guardians, imperilling Willy.


I identified an easy fix for that flaw, which is detailed somewhere in the Yahoo! Group.


This problem shouldn't affect the games you've just uploaded, since (as far as I can recall) there are no items in the game which are located in the bottom cell-row of any of the rooms.  But if the game were modified to that effect, then the flaw could rear its head.  Though if the graphical corruption were to occur in an air cell in the top cell-row, then it may not be visible unless the Air's PAPER and INK settings are different, such as in a room with a rope.

#11061 New tune

Posted by IRF on 19 May 2019 - 09:19 AM

Correct! Hip hop hip Hooray!!

#11055 New tune

Posted by IRF on 19 May 2019 - 12:28 AM

Thanks, as ever, to Richard Hallas' tone chart 'A Miner Triad'. ☺

#11054 New tune

Posted by IRF on 19 May 2019 - 12:13 AM

Just a bit of fun... See if you can recognise the in-game tune in the attached file...


EDIT: I've made a slight tweak to the second half of the tune in the additional attachment 'rev1', for a bit of variety.

Attached Files

#11035 JSW Main Sprite possible improvement?

Posted by IRF on 14 May 2019 - 10:43 PM

"jagged finger fix by Norman Sword"

The fix used to reduce the jagged finger look in the file mention in Post#7 is basically a copy of the code I placed on this website.
So it comes as a surprise that someone else has fixed this problem. Have they really? It seems to me that they have used my code.

This site mentions so often things like Goeff mode etc that this partial fix to this problem should be call "jagged finger fix by Norman Sword".
It was a problem that prior to my posts, was not fully understood in it's nature or how to remove. The code used to partially cure this problem
is basically the code I wrote.
If you have a problem with what I say here then please show me any code prior to the code I listed that did anything of the same nature.
Or any version of jsw(1) that fixed the problem prior to my posts.

Norman Sword, you were duly credited in the Readme file which accompanies the file by Metalmickey which is referred to in post #7 of this thread. :)
(Metalmickey also mentions me in the same sentence of that document, as it was I who recommended that he implement this since he was attempting to collate "fixes for all known bugs" in JSW, and I helped him to implement your fix into his project. However, the credit should really be all yours. [Having said that, I would say that I had some modest input into it, by encouraging you to 'synchronise' the updating of attributes for each character row in association with the associated eight pixel rows, an improvement which reduces another element of screen flicker.])

I have updated my post #7 to make it more explicit that you were the author of the 'Jagged Finger Fix'. (When I posted earlier, I thought I had made the authorship clear, but on reflection perhaps I didn't make it clear enough.)

#11029 JSW Main Sprite possible improvement?

Posted by IRF on 14 May 2019 - 02:36 PM

Thanks guys for your awesome replies..


Norman Sword,  wow i must say i've been playing your game (JSW 128 VK3) and it's amazing what you've achieved.... and yes you truly have perfectly corrected the Willy main sprite!

I've been playing your game on my PS Vita, with its OLED screen (using RetroArch & Fuse emulator), with a CRT overlay effect and it's just brilliant. ..Looks stunning & plays stunning.

The additions you've made to the JSW experience are truly mind-blowing to me, especially the way that Willy is invincible for a short time after losing a life, and also the way you can slowly break through floors.


....now the tricky bit  :thumbsup: ....Dear Mr Norman Sword, is there any chance you can be persuaded to release a standard regular version of Jet Set Willy but with the main sprite 'corrected' in the way you've achieved it in your game JSW 128 VK3? 


Sorry i know it's a bit cheeky to ask,  but i figured it's worth asking as it may be something relatively easy for you to do, considering your skills hehheh  :)  


I believe that another jswmm member, called Metalmickey, implemented the Norman Sword's fix for the flickering sprites into his 'JSW As Manufacturer Intended' project:




As well as fixing the 'jagged finger' imperfection, the patch also reduces the issue whereby the attributes of fast-moving entities can be noticeably delayed behind their pixels.  (You can see this in effect when Willy drops into 'Entrance to Hades' - his feet flicker in green as he falls, because green is the defined INK colour of the air cells and it provides a strong visual contrast with the yellow PAPER background in that room.  Try that manoeuvre in the original 'Jet Set Willy' and compare/contrast with the same manoeuvre in the 'As Manufacturer Intended' file.)


EDIT: I should point out that whilst the flickering is fixed/reduced in the aforementioned project, the speed of the game is not increased to anything like the same extent as is the case in Norman's more recent files (JSW 128 VK / VL).



As far as I can tell, the most recent version of that 'As Manufacturer Intended' project is the one which is attached to this post:




Since that version was uploaded, some more refinements were discussed (such as making the end-of-game toilet-dash appear more as if Willy is running, instead of sliding, to the toilet!), but I'm not sure if Metalmickey ever got round to incorporating those changes into a more recent build?

#11019 JSW Main Sprite possible improvement?

Posted by IRF on 13 May 2019 - 06:39 AM

Check out this topic - is that what you meant?:


#10963 [File] Jet Set Mini

Posted by IRF on 02 May 2019 - 12:55 PM

ThINK again...

#10951 Vote for your favourite JSW mod

Posted by IRF on 01 May 2019 - 07:04 AM

In any case, I feel sure that Danny will help to publicise the release of the bug-fixed version of the game at the Expo in Manchester this weekend...  :)

#10948 Vote for your favourite JSW mod

Posted by IRF on 29 April 2019 - 07:02 AM

Well that's true! In that sense, it continues a fine tradition!

#10942 Vote for your favourite JSW mod

Posted by IRF on 28 April 2019 - 05:23 PM

I am not necessarily in favour of "Maria vs. Some Bastards" winning the compo (I'm not strongly opposed to it either), but if it did, it would certainly put the game in the limelight for a few days, which in turn should give some free advertisement to the 2019 Bug-Fixed Version :). Provided the info about the existence of this version reaches the wider audience...


I suppose if the non-completable version was to win, without the completable version being widely known about, then it might ultimately lead to a certain amount of dissatisfaction in the result.

#10940 [File] Jet Set Mini

Posted by IRF on 28 April 2019 - 04:17 PM

I will have a look at the screenshots one day to see if I can spot what you mean, but it'll have to be after Manchester


Save it for a red-letter day.  ;)

#10932 Vote for your favourite JSW mod

Posted by IRF on 27 April 2019 - 10:44 PM

I see that 'Maria vs Some Bastards' has been nominated for the 'Favourite JSW Mod' award.  Hopefully it will be looked upon even more favourably now that it's completable!  ;)