Repton 3 Redux

[Rocketeer]

For the BBC Master 128/Master Compact

The attached disk image will run on the above machines only.
Approved by Richard Hanson of Superior Interactive.

On the disk image see files:-

readme - full instructions to get playing.
credits - various routines where they came from.
version - version history.
passwrd - passwords and edit codes for all the map files (note that the files are compressed so will not load into the editor,
you will have to use the original games, these uncompressed files can be loaded though).
licence - licence for the compression/decompression technology used and other information.

These are attached to this post and are available within your machine by changing to MODE 0, CTRL-N to scroll lock and then *TYPE <filename>.
Use the SHIFT key to page through the file.

Version 1.1 attached which addresses a few minor issues.

[danielj]

Exciting!

[gfoot]

Very nice, and it's great to see you active again! I played this game so much, you were one of my childhood heroes.

I didn't see mention in the readme of the fungus timer bug or the dependence of the in-game time on execution speed, which I think are the main things that sometimes made the original releases unplayable - do you know if these are fixed in this version?

Edit - playing through, the fungus bug appears to be fixed here, but not the time vs execution speed issue. This is most noticeable on NOW screen H which is impossible in some versions without abusing the skull death bug, and only just possible in this new version. I don't think it's meant to be that tight.

So if you go there with password SAVOURS, and run as fast as you can through the maze, in this version you might just about be able to get to the time capsule - perhaps due to optimizations elsewhere. In some other versions I've tried, you run out of time well before getting there. However, if you hold a key down - e.g. I use "X" - after entering the password, particularly at the time the ditty starts playing, then the game as a whole runs a little bit more smoothly, and then you can make it to the time capsule very easily. I don't know why holding a key at that point makes the game run more smoothly, but it'd be a great fix if it just did this all the time!

A quicker way to observe this is to only go as far as the square to the right of the transporter, and press Enter at that point - if you weren't holding "X" after typing the password then your time remaining will be about 404, while if you were holding "X" then your time remaining will be about 416. So on the whole over that section, the game is running about 5% slower if you don't hold down "X" while the ditty starts. I believe the actual amount varies depending upon how busy the game is (e.g. spirits being on the screen, whether the player is moving, etc).

[archie456]

very nice, impressive smooth scrolling, is the scrolling achieved by having the screen wider / taller than that displayed so the drawing occurs off screen?

I did notice the short Laurel and Hardy tune that plays when the player first starts, does not play fully (only about half) when the player starts a second game and the background tune starts halfway through.

[Rocketeer]

very nice, impressive smooth scrolling, is the scrolling achieved by having the screen wider / taller than that displayed so the drawing occurs off screen?

I did notice the short Laurel and Hardy tune that plays when the player first starts, does not play fully (only about half) when the player starts a second game and the background tune starts halfway through.

The time between the end of one frame and the start of the next is quite tight, only really enough time to transfer a row of 256 bytes so I do build up that row in a buffer with any monsters/spirits that happen to be there as well before sending to the screen.

Dont know about the intro tune only playing half a tune as you say. The backgound music is as per the original - it picks it where it last left off not resetting at all. I would have to check this but I think it's constantly playing the music, only sending the notes to the sound chip if music is enabled.

[Rocketeer]

Very nice, and it's great to see you active again! I played this game so much, you were one of my childhood heroes.

I didn't see mention in the readme of the fungus timer bug or the dependence of the in-game time on execution speed, which I think are the main things that sometimes made the original releases unplayable - do you know if these are fixed in this version?

Edit - playing through, the fungus bug appears to be fixed here, but not the time vs execution speed issue. This is most noticeable on NOW screen H which is impossible in some versions without abusing the skull death bug, and only just possible in this new version. I don't think it's meant to be that tight.

So if you go there with password SAVOURS, and run as fast as you can through the maze, in this version you might just about be able to get to the time capsule - perhaps due to optimizations elsewhere. In some other versions I've tried, you run out of time well before getting there. However, if you hold a key down - e.g. I use "X" - after entering the password, particularly at the time the ditty starts playing, then the game as a whole runs a little bit more smoothly, and then you can make it to the time capsule very easily. I don't know why holding a key at that point makes the game run more smoothly, but it'd be a great fix if it just did this all the time!

A quicker way to observe this is to only go as far as the square to the right of the transporter, and press Enter at that point - if you weren't holding "X" after typing the password then your time remaining will be about 404, while if you were holding "X" then your time remaining will be about 416. So on the whole over that section, the game is running about 5% slower if you don't hold down "X" while the ditty starts. I believe the actual amount varies depending upon how busy the game is (e.g. spirits being on the screen, whether the player is moving, etc).

Fungus wise the code changed from the original mark 2 game engine from Repton 3 to the expansion packs by adding a delay before it started spreading on all levels not just the first and that's the code I used for Redux.

Subjectively Redux runs a tad faster than the original versions so that would account for you able to complete the screen even though it's quite tight. The screens were designed by Superior and worked originally or maybe they altered them after feedback from customers and I've got an earlier version?

Interesting figures you've got there, I don't know what would be causing the degraded perfromance by holding the "X" key at this point. All the keys are read by direct keyboard access rather than using the operating system and returns a value if they're pressed or not. This runs in constant time so I don't know what else might be causing it at this point.

[Rocketeer]

Exciting!

It's November '86 all over again.

[gfoot]

Subjectively Redux runs a tad faster than the original versions so that would account for you able to complete the screen even though it's quite tight. The screens were designed by Superior and worked originally or maybe they altered them after feedback from customers and I've got an earlier version?

There is at least one case where they did that, in the Life of Repton's "Work" scenario - different releases of that game have a slight change in one of the maps. I don't think that was the case for Thru Time though, and this bug affects all versions of the game - it's worth doing the hold-a-key-down trick if you're playing a time-sensitive level!

Interesting figures you've got there, I don't know what would be causing the degraded perfromance by holding the "X" key at this point. All the keys are read by direct keyboard access rather than using the operating system and returns a value if they're pressed or not. This runs in constant time so I don't know what else might be causing it at this point.

Performance is actually better if you do hold a key down, not worse. You can see (on the old versions) the flicker at the sides of the screen extends much further down, if you didn't hold a key while the ditty played.

I tried to investigate this a year or so ago but didn't get anywhere - however I just bit the bullet and took some CPU traces in beebjit with and without holding down a key, so perhaps there'll be a clear difference there. The trace files are each about 13 million instructions long though...!

[archie456]

Dont know about the intro tune only playing half a tune as you say. The backgound music is as per the original - it picks it where it last left off not resetting at all. I would have to check this but I think it's constantly playing the music, only sending the notes to the sound chip if music is enabled.

I video captured the intro tune half playing if thats of use... (I should add that I'm using BeebEm).

[MillieTD83]

Dont know about the intro tune only playing half a tune as you say. The backgound music is as per the original - it picks it where it last left off not resetting at all. I would have to check this but I think it's constantly playing the music, only sending the notes to the sound chip if music is enabled.

I video captured the intro tune half playing if thats of use... (I should add that I'm using BeebEm).

That's a weird one. I'm sat with BeebEm open trying to reproduce it for it plays fine each time.

VLC Player didn't like the .avi file (just bombed out completely) - Windows Media Player didn't display video but did the audio. Very strange.

[danielj]

I just tried it in jsbeeb and it's all perfectly fine.

[gfoot]

I can reproduce archie's bug in BeebEm for Windows 4.19 - it happens if you die three times, then press Space to start again. Shift-R to restart doesn't cause it. What seems to happen is the screen dissolves into the level without waiting for the intro tune.

[geraldholdsworth]

Fantastic. Well done.

The movement isn't smooth, but that could just be because I'm on BeebEm on an M2 Mac.

Any chance of getting details on how the data files are compressed? (for Repton Map Creator, of course).

[Rocketeer]

Fantastic. Well done.

The movement isn't smooth, but that could just be because I'm on BeebEm on an M2 Mac.

Any chance of getting details on how the data files are compressed? (for Repton Map Creator, of course).

All the map files are compressed from the original files and use run-length encoding apart from the first &180 bytes which contain the new map small characters. As per the licence file decompression can be found here https://github.com/dmsc/zx02/blob/main/ ... -optim.asm (I optimised for 65c02) and the compressor which is a windows executable. I just put a batch file together to compress all files then the new characters are added at the start of file when written to the image by BeebAsm.

[Rocketeer]

I can reproduce archie's bug in BeebEm for Windows 4.19 - it happens if you die three times, then press Space to start again. Shift-R to restart doesn't cause it. What seems to happen is the screen dissolves into the level without waiting for the intro tune.

I have had a few issues with BeebEm's emulation that are not reproduced in jsbeeb. For example at the end of the direct keyboard read you need to execute a store to one of the 6522 via registers to re-enable it's use for the sound chip:-

LDA #&0B ;select auto scan of keyboard
STA system_via_orb_irb

Omitting this and running on BeebEm makes no difference to the sound output but on jsbeeb and actual hardware the sound is muted. So if this can be reproduced on either on these I'll take a look.

[gfoot]

Omitting this and running on BeebEm makes no difference to the sound output but on jsbeeb and actual hardware the sound is muted. So if this can be reproduced on either on these I'll take a look.

Yes, I can repro that bug on jsbeeb and on beebjit as well - after launching the game, entering the level, dying three times, then pressing space to start the next game, the screen dissolves immediately without waiting for the intro tune, and cuts it off halfway through when the dissolve finishes. It seems to be something to do with dying - if I reboot the system, enter the level, and shift-R out of it without dying, then the bug doesn't happen.

I don't think it's a sound bug, more like a timing issue with a delay loop not happening?

[Rocketeer]

I don't think it's a sound bug, more like a timing issue with a delay loop not happening?

Quite right about the delay loop, some how it had got missed off. Now re-instated and all's well. Also, the music speed was a tad slow so that has been restored to the original. Please download from the first post. Thanks.

[jms2]

Only played with this briefly, but I've got to say thanks and well done on this update. I do love these re-engineered versions of classic games.

[alastairhm]

Great work, played the first level on the b2 emulator, played amazing.

[beebman82]

This is awesome, thank you. It really feels like the definitive version

It is probably just me but I do miss the loading screen and the digitised speech "welcome to repton 3, from superior software...", I just always love a loading screen.

I do really like that you have included the levels from the addons. I wonder, is there a possibility you could add some sort of shortcut / menu option to load the "Life Of", "Thru Time" or "Around The World" instead of going to the load map file option.

Once again, great work, thank you, looking forward to continuing my Repton 3 adventures.

Thank you so much

[Rocketeer]

It is probably just me but I do miss the loading screen and the digitised speech "welcome to repton 3, from superior software...", I just always love a loading screen.

I do really like that you have included the levels from the addons. I wonder, is there a possibility you could add some sort of shortcut / menu option to load the "Life Of", "Thru Time" or "Around The World" instead of going to the load map file option.

No plans to re-instate the loading screen at present, I left it out originally as it wasn't my copyright to include it, but the other reason I left it out was disc space or rather lack of with all the extra map files added.

By loading them at the game level do you mean have a list of each game having the map files underneath associated with that game to choose from?
That could be useful.

Later this year I'm going to re-jig the code to use just 6502 as I've received a few requests for regular BBC versions (with one bank of sideways ram). Shouldn't be too difficult, I originally went down the route of using 65c02 code as I thought the new features would slow the game down and if the game slows down all the tightly timed levels become more difficult or impossible to complete.

[beebman82]

Hi,

Totally understand about the loading screens etc, need to be very careful with copyright.

By loading them at the game level do you mean have a list of each game having the map files underneath associated with that game to choose from?
That could be useful.

Yes, you are exactly right, just something visual to be able to easily load a level from each expansion without having to reference out to an external file to see which is which.

Not sure how much work that would be, but it would be a lovely feature to have.

The version you have already published is great and I will continue to enjoy for a long while.

Many thanks.

[gfoot]

Now that these are all in one package, I've been meaning to play through the whole thing from start to finish, in the order the levels were originally released, and so I thought I'd try to live-stream it on twitch this evening. I should be able to complete them all, but will probably have forgotten how to do some of them, and certainly there are some levels I just don't have good strategies for.

This may be over-ambitious as I also haven't done much streaming, so the whole set-up might just not work at all - but there won't be many viewers so it won't matter much if it does. I'll see if I can share the video afterwards as well, however far I get - or maybe cut it up into separate bits for each scenario!