IRF

The wording 

This means this version contains 40 caverns, starting with the original 20 caverns, then continuing on with another 20 caverns originally desisigned by Ligan. (of those 20 caverns, some have been redesigned by me)

was added to the main description

The above pokes - demystified into actual Z80 code
 

opcode                    address                 address                  comment
                                hex #8F85             decimal 36741    ; note:- listed one byte earlier
call #90fe               ;#cd,#fe,#90                                      ; the original call to the score routine
changed to
call #9352              ;#cd,#52,#93         ;205,82,147         ; note:- the call opcode is included here

this routine is a copy of the Item collect sound in Jet Set Willy
opcodes                ;address              ;address
;                             ; hex                     ; decimal
;                             ;#9352                 ;37714

ld a,(#8073)          ;#3a,#73,#80      ;58,115,128              ; get border colour
ld c,#80                 ;#0e,#80              ;14,128                   ; set loop counter (duration)
sfx:
out (#fe),a             ;#d3,#fe              ;211,254                  ; set border + ear + mic
xor #18                  ;#ee,#18              ;238,24                   ; toggle ear + mic bits
ld e,a                      ;#5f                     ;95                          ; save the border + ear + mic state in {e}
ld a,#90                 ;#3e,#90             ;62,144                    ; calculate a pitch
sub c                      ;#91                    ;145
ld b,a                      ;#47                   ;71                            ; the calculated pitch to {b}
ld a,e                      ;#7b                   ;123                          ; restore border + ear + mic back from {e} to  {a}
sfx_loop: 
djnz sfx_loop          ;#10,#fe             ;16,254                   ; loop (delay) for the pitch
dec c                       ;#0d                  ;13                           ; decrease the time counter
dec c                       ;#0d                  ;13
jr nz,sfx                   ;#20,#f0           ;32,240                    ; keep looping till out of time, {c}=0

jp #90fe                 ;#c3,#fe,#90     ;195,254,144            ; jump to the score routine
 
Addendum.
the JSW sound routine uses absolute address's for picking up the border colour. The actual routine uses relative jumps thoughout. This means this routine can be placed at any address, without having to change any of the routines data. The only change would be calculating the actual address that the routine sits at.

Addendum 2
A re-write can shorten the above 24 byte routine by 3 bytes. (I have not listed the re-write)
 

Probably more in the "loosely based on"-category. Based on a quick image search.

I'm guessing from the name that Eddie's Forest is an updated version of (or loosely based on) The Endorian Forest?

I do use a Mac primarily, yes, and still RISC OS too, some of the time. I only use Windows when I have to, because I really dislike it.
I do get frustrated, though, by the fact that so many of the emulators, editors and tools that I’d like to use are typically Windows only. Or Windows and Linux only, but never Mac. It’s though there’s a conspiracy only ever to support crap user interfaces! 😉
Nevertheless, there are still lots of options on the Mac, and plenty of Spectrum emulators (including two separate ports of Fuse).
When I want to use PC software I typically use Parallels Desktop, which is an absolutely fantastic product and typically just as fast as a real PC. Or there are several Wine-based alternatives that perform really well too; CrossOver is a good commercial option with a range of enhancements, but there are several free Wine-based options.
The complication of recent years, though, is the move from Intel to ARM in recent Apple Silicon Macs, as this has had ramifications in terms of PC emulation/virtualisation. Basically, it means that if you’re on a modern M-series Mac, then (a) you have to virtualise a recent ARM-based version of Windows under Parallels, and (b) a lot of the Wine-based options are Intel-only, so won’t work at all. But it could be worse. If you’re happy to use Windows 11 under virtualisation, then it’s likely to run everything you want, and as for Wine, CrossOver somehow still works (very well) on the latest M-chips – and new freeware options seem to keep appearing.
Of course, it would still be vastly preferable to have native tools on the Mac, so if John or anyone else were to build JSWED for the Mac, I’d be extremely interested.
At one point I did start making a half-hearted attempt to get JSWED working on the Mac myself. Unfortunately my personal circumstances these days are such that I have very little free time of my own in which to tinker, so I can’t say anything very useful about JSWED specifically, except that I’m sure it’d work in something like Parallels or CrossOver. But I’d love it if someone created a decent native port. If that happened, it’d probably give me the incentive to start on a new JSW game myself.

That much is technically true, in so far as the room Hidden Chamber is first encountered early on in the game (before Styx) - where only the area to the right of the partition in that room is accessible - and then later on in the game (after Styx, I believe) a pair of teleporters allows you access into the area of Hidden Chamber to the left of the partition, and back again to the same 'zone' (the jungle-themed area - not sure how that works in a sub-aqueous environment but there you go)...
... That's where the problem lies - once you teleport back to an earlier part of the layout, you cannot do anything but teleport forwards again. So a second bite of the Styx Cherberus isn't possible.

It is a mark of how HUGELY chuffed I am about this that I ploughed through through the forum's MONUMENTALLY BROKEN signup process to post a comment. The original idea for The Lost Levels was in fact to do it on the Speccy, so it's absolutely brilliant to see it finally come home all these years later. The DS version is my favourite gaming-related thing I've ever been involved with, and now the journey feels complete. Great work 🙂
 
PS Eddie's Forest isn't an original DS level, it's actually taken from the Acorn Archimedes port.

I think that's it really , in that it does not matter how far MW falls if he hits one of these, he's safe (and bounces back up a bit) very similar to Dynamite Dan
This just sort of makes him fall a lot faster , I can't recall -if- there's anything else to prevent a fatality with the fall as I do remember one cavern had this near the top, so he'd fall say 2/3rds the way down.
 
Sorry the above is a bit vague.

I'm sure patches could be devised in JSW64 which replicated both the safely-break-a-long-fall trampoline and the vacuum descent blocks. Even if they involved an adjustment to Willy's air fall counter, etc, based on a check of Willy's coordinates compared against a hardwired value (the air cells just above the blocks in question), rather than recreating generic new block types and associated major changes to the game engine. (Though the latter would be preferable if you wanted to create brand new caverns and employ the new blocks elsewhere.)

Well if you're trying to replicate the original caverns, and since the 'technology' is readily available (via the patch vector system)... 

However, I have now managed to find a way to collect those two awkward items in Cheat Mode. I manoeuvred Terry to an equivalent position to directly underneath the two items, in another room, and then switched rooms (via the cursor-based JSW64 Cheat Mode room-swap mechanism).
That way, I got Terry embedded in the floor directly underneath the items, with his sprite's pixels aligned with the items as much as possible. I then jumped straight upwards. When you are mid-jump, the sprite's INK attribute stretches up through three character rows at times, and since the Terry sprite is only about five pixels high, an attribute collision with the items was able to take place before a pixel collision with the guardian caused either death, or (with Forcefield activated) the switching off of the Draw Willy routine (which needs to be executed in order to collect items).
VID_20240430_094214.mp4

That much is technically true, in so far as the room Hidden Chamber is first encountered early on in the game (before Styx) - where only the area to the right of the partition in that room is accessible - and then later on in the game (after Styx, I believe) a pair of teleporters allows you access into the area of Hidden Chamber to the left of the partition, and back again to the same 'zone' (the jungle-themed area - not sure how that works in a sub-aqueous environment but there you go)...
... That's where the problem lies - once you teleport back to an earlier part of the layout, you cannot do anything but teleport forwards again. So a second bite of the Styx Cherberus isn't possible.

Yes, the linear nature of the route doesn't allow for dropping down into Styx twice during the same game AFAICT.
The question would be whether there isn't some kind of exit somewhere which allows Terry to go back to an earlier part of the route and drop down into Styx again. However, I couldn't find any such exit, and the layout of the map doesn't suggest there is one.

Ian, thank you SO MUCH for analysing this issue! Indeed, you have put my mind at rest that I haven't missed anything. And the timing has been very helpful as I will soon set out to re-record the first file in question (the Yellow version).
I also congratulate you on collecting the last remaining items in the Cheat mode 👍. This is not pertinent to my YouTube videos (as I don't use any cheat modes in them), but a testament to your tenacity in pursuing the specified goal 😉.

I have interrogated the code for the Yellow Edition.
I looked at all the rightward exits from the rooms (at Offsets #EA in each pair of pages across the four banks of room data), but I couldn't find and trace of a room exit that would lead into the Forbidden Holy Grounds at the top left of either the Hidden Chamber or the Secret Load and Kill Screen.
I then scrutinised the teleport code (which took a while as I had to re-learn where the teleport data is stored in JSW64, and what format it is stored in), in case any teleporters (other than the ones you already know about) could provide access to those unobtainable items. But alas, no such luck.
***
I didn't investigate the uncollectable items in the Cyan Edition because, based on your description, they just seem to be a subsection of the uncollectable ones from the Yellow Edition?
***
I didn't check out the Vector Edition either, but if you say that there is no way to be able to drop down into Styx twice during the same game (presumably because the linear nature of the route doesn't allow for that?), then I can't see how you can collect both items (unless a gust of wind can blow Terry sideways as he descends - or I suppose it might be a sea current given the nature of the setting - or unless he can take a fat pill to expand his sprite across four columns!)
***
So in summary, I couldn't find a way to obtain any of the 'Forbidden Holy Items', but at least hopefully I have put your mind at rest that you haven't 'missed a trick' in that regard!?
[Of course, there is always the JSW64 Cheat Mode...]

I have interrogated the code for the Yellow Edition.
I looked at all the rightward exits from the rooms (at Offsets #EA in each pair of pages across the four banks of room data), but I couldn't find and trace of a room exit that would lead into the Forbidden Holy Grounds at the top left of either the Hidden Chamber or the Secret Load and Kill Screen.
I then scrutinised the teleport code (which took a while as I had to re-learn where the teleport data is stored in JSW64, and what format it is stored in), in case any teleporters (other than the ones you already know about) could provide access to those unobtainable items. But alas, no such luck.
***
I didn't investigate the uncollectable items in the Cyan Edition because, based on your description, they just seem to be a subsection of the uncollectable ones from the Yellow Edition?
***
I didn't check out the Vector Edition either, but if you say that there is no way to be able to drop down into Styx twice during the same game (presumably because the linear nature of the route doesn't allow for that?), then I can't see how you can collect both items (unless a gust of wind can blow Terry sideways as he descends - or I suppose it might be a sea current given the nature of the setting - or unless he can take a fat pill to expand his sprite across four columns!)
***
So in summary, I couldn't find a way to obtain any of the 'Forbidden Holy Items', but at least hopefully I have put your mind at rest that you haven't 'missed a trick' in that regard!?
[Of course, there is always the JSW64 Cheat Mode...]

I'm sure patches could be devised in JSW64 which replicated both the safely-break-a-long-fall trampoline and the vacuum descent blocks. Even if they involved an adjustment to Willy's air fall counter, etc, based on a check of Willy's coordinates compared against a hardwired value (the air cells just above the blocks in question), rather than recreating generic new block types and associated major changes to the game engine. (Though the latter would be preferable if you wanted to create brand new caverns and employ the new blocks elsewhere.)

That's funny, last week I was randomly thinking of that DS game and then completed it. I was especially interested in the exclusive levels made for it and tried translating them in spectrum version. However, the DS has a slightly bigger screen which makes it quite awkward to do.
 
They are pretty different. SAM Coupé trampolines' main purpose is cancelling your fall damage which JSW64 tramp cells don't do. They just make you jump when you're standing on them which SAM Coupé trampolines also don't do.
The JSW64 engine can totally handle "The Space Shuttle" or "Back to Work" though.

I'm pretty sure trampoline cells are a standard feature in the JSW64 game engine. They have been used in some released games. I don't know if they work exactly like the ones in the SAM Coupé version, but even if they don't, it's certainly better to use them than not to use any kind of 'trampoline-like' cell where they should be (as per the original version).

The patch vector feature of the JSW64 game engine could maybe help you to achieve the special effects in some caverns referred to above (trampolines, vacuum descents)?

The patch vector feature of the JSW64 game engine could maybe help you to achieve the special effects in some caverns referred to above (trampolines, vacuum descents)?

We have gone over 16,000 posts on the forum today, 25th April 2024! 😁
You can't see it on the main page with this new version of the software (because it only shows a rounded-up number), but we have been tracking it on the admins' side and it's just happened. A big thank you to everyone who keeps the forum going! 🙂 

I think @Richard Hallas uses a Mac, so he may have some experience in this regard? 

I think @Richard Hallas uses a Mac, so he may have some experience in this regard? 

I think @Richard Hallas uses a Mac, so he may have some experience in this regard?