JSW for Camputers Lynx

[jetsetdanny]

Thanks for this, Richard - it's very interesting! 👍

[MtM]

Bravo to everyone involved, real bit of JSW history here, thank you.

[Mike]

On 3/17/2025 at 2:28 AM, jetsetdanny said:

Welcome to the forum, Mike! 🙂 And thank you for this information - it's very interesting! 👍

Thank you. Pleased to be among fellow retro enthusiasts!

[Mike]

On 3/17/2025 at 1:59 AM, Richard Hallas said:

does the preserved version contain the full game or the reduced-size 48K version?

My version is 96k only. When they upgraded the Lynx 48k to 96k, they also upgraded a few rom routines, which means it won't even load on a 48k (you get a "not yet implemented" error message). It's no problem these days, because most Lynx enthusiasts will upgrade to 96k anyway.

Quote

There are seemingly only two stand-alone Lynx emulators for modern systems

My favourite for simplicity is "Jynx". It's very robust and well written, by Jonathan Markland. Its seems to run *almost* all Lynx software.

"Pale" lacks polish, and can be overly complicated (although very feature rich for hardcore enthusiasts/developers). Both are PC mainly, although you may find a linux variant.

As you say, neither are actively maintained.

I occasionally use Mame, but it can be confusing to configure. I have had fun using it's inbuilt debugger though, to step through the Lynx ROM code, etc.

[Richard Hallas]

14 minutes ago, Mike said:

My version is 96k only. When they upgraded the Lynx 48k to 96k, they also upgraded a few rom routines, which means it won't even load on a 48k (you get a "not yet implemented" error message). It's no problem these days, because most Lynx enthusiasts will upgrade to 96k anyway.

My favourite for simplicity is "Jynx". It's very robust and well written, by Jonathan Markland. Its seems to run *almost* all Lynx software.

"Pale" lacks polish, and can be overly complicated (although very feature rich for hardcore enthusiasts/developers). Both are PC mainly, although you may find a linux variant.

As you say, neither are actively maintained.

I occasionally use Mame, but it can be confusing to configure. I have had fun using it's inbuilt debugger though, to step through the Lynx ROM code, etc.

Thanks for all that. That's odd about JSW not loading on a 48K machine, because the advert does imply that there's a reduced-size version of the game for that system. Given that both sizes of machine were available at the same time, the implication is that the game distinguishes between them and loads the appropriate code. (Or perhaps there's a cut down version on the other side of the tape?) Anyway, if the version that's been preserved is the full one then that's the most important thing.

I also find it curious that a 96K Lynx was needed to run JSW in full anyway, since the game was written originally for the 48K Spectrum, and its code and data is in fact only 32K in size anyway! But of course, the Lynx is a totally different system architecture, and maybe it needs loads of memory for its screen, for example. (The Spectrum's screen was very efficient, at under 7K.)

I'll look into Jynx, thanks. Shame there's no Mac version, but I'm sure it'll run under Crossover or some other emulation/virtualisation option.

[Mike]

The Lynx 48K only has about 14k of useable RAM - the rest is mainly graphics ram. This isn't so unusual - back in the day, the Spectrum originally only had 16k (although they dropped that version fairly quickly). One of the selling points of the Lynx was that it could be upgraded (albeit by returning it, to be factory upgraded). So the "48k"  label was creative marketing! The lynx had four 8k colour banks, which was rather generous at the time. But it did raise the question "where's all my ram gone?" as soon as you got it home.

[Richard Hallas]

On 3/20/2025 at 10:09 AM, Mike said:

The Lynx 48K only has about 14k of useable RAM - the rest is mainly graphics ram. This isn't so unusual - back in the day, the Spectrum originally only had 16k (although they dropped that version fairly quickly). One of the selling points of the Lynx was that it could be upgraded (albeit by returning it, to be factory upgraded). So the "48k"  label was creative marketing! The lynx had four 8k colour banks, which was rather generous at the time. But it did raise the question "where's all my ram gone?" as soon as you got it home.

I thought it must be something like that. The Spectrum (especially the 48K version) was fairly unusual for having a comparatively large amount of free memory available, partly because 48K was relatively generous compared to the 32K that was common on many other machines, and the fact that its screen required only a little under 7K of it, leaving loads of room for code and data. There was a little over 40K of usable RAM on a 48K Spectrum, which was a lot, really.

Contrast in particular with the BBC Micro. That too was a great machine with many fantastic features, but it was so hampered by its lack of RAM and its hungry screen modes. A decade later, Acorn's approach to screen modes showed its worth on the Archimedes range, but on the BBC they demanded an uncomfortably high percentage of available RAM. A 32K BBC Micro only had about 27K of usable RAM at best, and then the more demanding screen modes (the ones with high resolutions or all the available colours) ate up 20K of it, leaving only around 7K or so for the program. (You could compare it to a 16K Spectrum in terms of available program/data memory.)

This is why I was always such a supporter of the Spectrum's eccentric approach to its screen display. Yes, character-level colour resolution (leading to the dreaded attribute clash) was a major compromise, BUT it did mean that you could always have full resolution and all the colours on the screen at once, with no further sacrifices to be made… and it still took up only a very modest amount of RAM. Not only was it a great solution to the problem, but it gave the Spectrum most of its character!

The BBC's trick up its sleeve was Teletext (MODE 7) graphics, and that brought similar benefits: a colourful screen mode with a useful resolution (40x25 characters) in only 1K of RAM. Very useful, but its big compromises were (a) character-based colours AND graphics and (b) graphics of only an extremely low resolution (2x3 per character space). This did, of course, mean that you couldn't really do graphical games in Teletext, other than mainly text adventures with very primitive illustrations. Mind you, having said that, it's not long since someone produced a version of Elite (yes, the 3D space game) that runs entirely in Teletext mode, just to prove a point. (It has extremely low resolution graphics, as you'd expect, but it works and is an interesting novelty.)

Anyway, I know very little about the Lynx, but with 96K or 128K of RAM and graphics with pixel-resolution colour, it ought in theory to have been able to do really impressive things. It's a shame that it apparently had such limitations as it did (i.e. extremely slow graphics handling and seemingly an inability to scroll its screen – based on reviews I've read in the past). Even so, games like JSW ought to have worked well on that machine, I'd have thought.

As a matter of interest regarding the Jynx emulator… I'm interested to notice that on its Github page, there's already provision for a Mac build, and the author explicitly says he'd like a RISC OS version too, particularly for use on the Raspberry Pi. (RISC OS is an OS very close to my heart.) The only reason these things don't exist is that no-one with the appropriate expertise has stepped up to do the porting, which is a great shame. It's a pity that Jynx wasn't written sooner, because RISC OS actually used to be absolutely awash with good emulators; it was by far the best platform for emulating other systems at one time, and I can think of a few people from years gone by who'd probably have jumped at the chance of producing a RISC OS version of Jynx. But the world moves on…

[Spider]

15 hours ago, Richard Hallas said:

Contrast in particular with the BBC Micro. That too was a great machine with many fantastic features, but it was so hampered by its lack of RAM and its hungry screen modes. A decade later, Acorn's approach to screen modes showed its worth on the Archimedes range, but on the BBC they demanded an uncomfortably high percentage of available RAM. A 32K BBC Micro only had about 27K of usable RAM at best, and then the more demanding screen modes (the ones with high resolutions or all the available colours) ate up 20K of it, leaving only around 7K or so for the program. (You could compare it to a 16K Spectrum in terms of available program/data memory.)

To be fair the 'rebuilt' Manic Miner and JSW1 for these are much improved and have a 'spectrum' feel to them.

[Richard Hallas]

3 minutes ago, Spider said:

To be fair the 'rebuilt' Manic Miner and JSW1 for these are much improved and have a 'spectrum' feel to them.

Oh yes, indeed they do. I think the new BBC and Electron conversions are brilliant, and show what was theoretically possible back in the day if you really took the trouble to do a good conversion job. It's worth pointing out, though, that to some extent it's been achieved by clever techniques such as changing screen mode partway down the screen (in effect) so that the upper part of the display is in one mode and the lower in another. In effect, that allows for two benefits: less screen memory being wasted unnecessarily, and more colours being displayed at once than is theoretically possible. It's quite a common trick on the BBC to mix two or more screen modes in this way (e.g. in Elite, the instrument display at the bottom of the screen is in a different screen mode than the wireframe 3D graphics and text display in the main area above it), and its main downside is that it's quite hard for the programmer to do!

Anyway, yes, the new BBC versions of MM and JSW are indeed much closer to the originals than the official conversions. They look better, play better and are smoother, faster and less flickery. A real expert job. Of course, to be fair to the original programmer, the conversions done back in the 80s were probably produced under much greater time pressure, and the programmer back then may not have been familiar with certain techniques that are well known to today's retro hobbyists. I don't mean to be unkind about the original BBC conversions; at least BBC versions were released back then! But the modern releases are, of course, hobby projects, written by an enthusiast who really knows what he's doing, in his own time without pressure to be ready for a commercial deadline, so of course they're very much better.

[Spider]

On 3/22/2025 at 2:42 PM, Richard Hallas said:

It's quite a common trick on the BBC to mix two or more screen modes in this way

Ah yes I was aware of that , and the 'upgraded' (updated?) versions make use of this, the Electron Manic Miner is a good thing too.

Regarding the newer JSW and MM as you know he took the opportunity to add more colours too which is a good thing. I do rate them quite highly.