Search found 503 matches

by kieranhj
Mon Nov 20, 2017 12:22 pm
Forum: other vintage computer hardware, software and games
Topic: Game Engine Black Book: Wolfenstein 3D
Replies: 0
Views: 30

Game Engine Black Book: Wolfenstein 3D

I mentioned this book to a few folks at ABUG this weekend: http://fabiensanglard.net/Game_Engine_Black_Book_Release/index.php Highly recommended if you are interested in the inner workings of the 386 CPU, how horrendous VGA was to program for (and I thought the Beeb screen buffer arrangement was bad...
by kieranhj
Mon Nov 20, 2017 10:28 am
Forum: emulators
Topic: Emulator support for VideoNuLA
Replies: 39
Views: 2336

Re: Emulator support for VideoNuLA

When I was tweaking the row timings to get the multiple ruptures working, I found that adjustments in the timings sometimes caused extra scanlines at the top of the display (I guess because the overall frame timing wasn't quite right). It's possible that the timing is more critical than it should b...
by kieranhj
Mon Nov 20, 2017 10:24 am
Forum: emulators
Topic: Emulator support for VideoNuLA
Replies: 39
Views: 2336

Re: Emulator support for VideoNuLA

Hey folks, After meeting RobC at ABUG this weekend, and excitedly trying my real NULA for the first time, I implemented the missing horizontal scroll and left blank features from b-em. This is not an official release as the changes will need to be rolled up into the Stardot repo master branch after ...
by kieranhj
Fri Nov 17, 2017 2:56 pm
Forum: wanted
Topic: Wanted: CUB Microvitec Monitor
Replies: 1
Views: 50

Wanted: CUB Microvitec Monitor

Hey folks, Does anyone have a classic CUB Microvitec monitor that they would be willing to part with for a reasonable sum please? In terms of collection I am based in Farnham, Surrey but normally attend the ABUG events, including this weekend's in Leicester. I'm not in a hurry but if one comes up sp...
by kieranhj
Fri Nov 17, 2017 2:16 pm
Forum: upcoming and recent events & exhibitions
Topic: ABUG EAST MIDLANDS (Winter Warmer) 17-19 November 2017 (Leicestershire) BOOKING THREAD
Replies: 129
Views: 3725

Re: ABUG EAST MIDLANDS (Winter Warmer) 17-19 November 2017 (Leicestershire) BOOKING THREAD

sbadger & I aiming to be with you all about 10.30am Saturday. I will be trying out POP on my Master (maybe doing some work on it), asking RobC nicely to fit my NULA and likely looking at implementing the NULA scrolling functionality into b-em.
by kieranhj
Wed Nov 15, 2017 5:05 pm
Forum: projects
Topic: Starting a Prince of Persia port...
Replies: 129
Views: 7889

Re: Starting a Prince of Persia port...

OK. Having put on my 8-bit Acorn hacker hat and suggested tricks for scavenging more RAM from the Master, I'll now take it off and instead put on my computer sciencist hat... I've not seen this code, but I assume that there's a large pool of sprites to plot, and a relatively small number of routine...
by kieranhj
Tue Nov 14, 2017 5:44 pm
Forum: projects
Topic: Starting a Prince of Persia port...
Replies: 129
Views: 7889

Re: Starting a Prince of Persia port...

I still feel like there should be no need for the double buffer. Even if the player plot is 140 scanlines, and the save/restore background 40 scanlines each, that still comes within the frame budget - so with raster timing so that you start the erase when the beam hits the screen block to restore g...
by kieranhj
Tue Nov 14, 2017 5:21 pm
Forum: projects
Topic: Starting a Prince of Persia port...
Replies: 129
Views: 7889

Re: Starting a Prince of Persia port...

If there really is no way to make the code more compact and it really is only 2K you need, you could just shrink MODE 2 by a little instead of resorting to MODE 5? Shaving 32 pixels off the bottom would give you 2560 bytes. Or you could shave just 16 pixels and have 1280 bytes in each of main and s...
by kieranhj
Tue Nov 14, 2017 1:42 pm
Forum: programming
Topic: 6502 Stack
Replies: 8
Views: 294

Re: 6502 Stack

As BigEd said. If you PLA stuff off the stack then you are at the mercy of interupts before the data is corrupted. You can, however, use the data freely & directly within the stack after it has been PHA'd before you PLA or reset the stack pointer. This is what the Exile (and PoP) sprite routine ...
by kieranhj
Tue Nov 14, 2017 1:36 pm
Forum: projects
Topic: Starting a Prince of Persia port...
Replies: 129
Views: 7889

Re: Starting a Prince of Persia port...

Looking forward to seeing this :D Given that it's already Master-only, is it worth thinking about just requiring an extra 16K of sideways RAM? I'm guessing that many Master owners have a cartridge that gives RAM in slot 0/1 or 2/3. Since the original game runs on an Apple II, and there have been C6...
by kieranhj
Tue Nov 14, 2017 10:52 am
Forum: projects
Topic: Starting a Prince of Persia port...
Replies: 129
Views: 7889

Re: Starting a Prince of Persia port...

OK folks. I'm long overdue an update for you all. There is good news and bad news. :D The good news is that I managed to refactor the memory usage to remove all the gameplay code from SHADOW RAM (not a trivial task) and implement screen double-buffering for MODE 2. Without wanting to sound too pleas...
by kieranhj
Sat Nov 04, 2017 5:41 pm
Forum: software: classic games
Topic: Exile
Replies: 49
Views: 2988

Re: Exile

Kevin unearths his pre-release version albeit by a week or so for copy protection purposes it looks like: https://www.facebook.com/groups/2204586455/permalink/10154874866966456/. Hopefully he can spill more beans on here perchance?! [-o<
by kieranhj
Sun Oct 29, 2017 12:46 pm
Forum: software: other
Topic: BeebAsm BASIC2 assembler O% equivalent?
Replies: 8
Views: 287

Re: BeebAsm BASIC2 assembler O% equivalent?

I looked back at the relocdemo that comes with BeebAsm and it has the unsatisfactory solution of defining an OFFSET variable and then manually patching up any absolute address references. :-k I bet this was on Rich’s to do list (and might even be a feature in one of the branches on GitHub - reminds ...
by kieranhj
Fri Oct 27, 2017 10:11 pm
Forum: software: classic games
Topic: BBC Elite Which is the best version? Or do they differ?
Replies: 26
Views: 1551

Re: BBC Elite Which is the best version? Or do they differ?

The Master version had double-buffered graphics, thanks to the Master's shadow RAM, so while the frame rate isn't as good as the Tube version the display looks generally a lot better. Ahhh, that makes sense. Thanks for the clarification. I had often wondered. Shame there's no Master Turbo version t...
by kieranhj
Fri Oct 20, 2017 9:28 pm
Forum: projects
Topic: Starting a Prince of Persia port...
Replies: 129
Views: 7889

Re: Starting a Prince of Persia port...

This is what I got for PoP on the idle screen: ...I suspect batching by 8-byte blocks or similar might be better (or more likely some actual visualisation...) I'll see what I can knock up! Thanks Matt! I will cross reference against the assembly in err, two weeks. I expect you to have a full 6502 p...
by kieranhj
Fri Oct 20, 2017 9:07 pm
Forum: projects
Topic: Starting a Prince of Persia port...
Replies: 129
Views: 7889

Re: Starting a Prince of Persia port...

Perhaps you've considered this but if not.. Do all the sprites need to be redrawn every frame? Perhaps you could interleve non player sprites on odd & even frame redraws, like the torches? Can you cull plots which would put the same sprite & animation frame in the same location as the previ...
by kieranhj
Fri Oct 20, 2017 5:21 pm
Forum: projects
Topic: Starting a Prince of Persia port...
Replies: 129
Views: 7889

Re: Starting a Prince of Persia port...

Re: profiling...what do folks use for profiling? I just realised there's a golden opportunity to add something cool to jsbeeb for profiling purposes, and wondered if other emulators already have this? Nothing, just a good old fashioned macro for setting the background colour. :( I was pondering ext...
by kieranhj
Fri Oct 20, 2017 5:14 pm
Forum: projects
Topic: Starting a Prince of Persia port...
Replies: 129
Views: 7889

Re: Starting a Prince of Persia port...

Nice work Kieran, it's really coming on well! Just to be clear, how is the sprite erasing currently working? Are you storing screen bytes before plotting the sprites, and then just copying them back over the top to erase? (i.e. a direct store, rather than the Exile type routine). I feel there must ...
by kieranhj
Fri Oct 20, 2017 11:58 am
Forum: projects
Topic: Starting a Prince of Persia port...
Replies: 129
Views: 7889

Re: Starting a Prince of Persia port...

Hey folks, thought I'd post a quick update since I'll be on holiday for a couple of weeks from Sunday. I have been continuing development, mostly focused on optimising the sprite plot and trying to get the game running as fast as possible. I've had a good bit of success unrolling the various sprite ...
by kieranhj
Wed Oct 18, 2017 9:42 am
Forum: upcoming and recent events & exhibitions
Topic: London Show / Saturday 28th October 2017
Replies: 26
Views: 1268

Re: London Show / Saturday 28th October 2017

If anyone Arcadian maybe? wants to have a version of PoP running on real Master hardware then let me know and I'll send you a new WIP disk image. Still a long way from being finished but definitely made a lot of performance improvements recently.
by kieranhj
Wed Oct 18, 2017 9:39 am
Forum: software: classic games
Topic: Exile
Replies: 49
Views: 2988

Re: Exile

I wonder if such a subtle and pernicious anti piracy scheme has ever backfired, in that it's damaged the reputation of a title. If something was widely copied but the game came across as difficult or buggy ,word of mouth for actual prospective buyers would be poor? Potentially. It is possible to be...
by kieranhj
Tue Oct 17, 2017 8:16 pm
Forum: software: classic games
Topic: Exile
Replies: 49
Views: 2988

Re: Exile

A good 20 years ago now, I worked on a game on the Playstation called Medievil. Sony had just introduced a library called Libcrypt, which took advantage of the fact that the Playstation hardware could read raw data from CDs, and that all releases were mastered with deliberately incorrect correction...
by kieranhj
Fri Oct 13, 2017 9:04 am
Forum: introduce yourself
Topic: Hi All.!
Replies: 11
Views: 332

Re: Hi All.!

spark001uk wrote:Good morn/afternoon/eve depending where you are,

Just a quick joiner's hello from finest Surrey UK.!

Welcome Spark! Whereabouts in Surrey are you? There are a couple of us down in the south-west corner.
by kieranhj
Wed Oct 11, 2017 12:15 pm
Forum: projects
Topic: Starting a Prince of Persia port...
Replies: 129
Views: 7889

Re: Starting a Prince of Persia port...

Hi, sorry it's taken me so long to pipe up in this thread, I can assure you I've been excitedly reading every update, trying out every test version as soon as they've been posted! Am simply amazed at how smooth/fast it's looking already and can barely believe how in an instant it went from mere con...
by kieranhj
Wed Oct 11, 2017 9:32 am
Forum: projects
Topic: Starting a Prince of Persia port...
Replies: 129
Views: 7889

Re: Starting a Prince of Persia port...

As always, thanks for the kind words everyone! Helps me keep up the motivation to get things finished. Kieran, do you think you might have room to double buffer just the bit where the player is, or at least build it off-screen? I've been doing some profiling to take a look at how the screen draw wor...
by kieranhj
Mon Oct 09, 2017 11:32 am
Forum: software: classic games
Topic: Hunchback for VideoNuLA (16 colours)
Replies: 8
Views: 459

Re: Hunchback for VideoNuLA (16 colours)

No rush - I still need to get my head around exactly what the issue is. Let me see if I can pin down a test case - might be a little while as I'm looking at getting my Flex port running on the GoSDC. Thanks, that would be helpful. Maybe I can also get around to implementing the sub-byte scrolling a...
by kieranhj
Sun Oct 08, 2017 7:47 am
Forum: software: classic games
Topic: Hunchback for VideoNuLA (16 colours)
Replies: 8
Views: 459

Re: Hunchback for VideoNuLA (16 colours)

Playing this on a real machine today, I realised that I'd forgotten to set the VideoNuLA palette for colour 8 and this caused flashing blocks around the lives counter. B-Em doesn't seem to have this issue for some reason. Ah, I must have misunderstood how flashing colours are handled on NULA. Let m...
by kieranhj
Sat Oct 07, 2017 2:11 pm
Forum: emulators
Topic: Recommended emulator for Linux?
Replies: 7
Views: 379

Re: Recommended emulator for Linux?

It has gone a bit quiet, but I've just added Kieran's NULA work: https://github.com/stardot/b-em/pulls it's currently waiting for review (from Steve or Kieran). Oop, yes. I did take a cursory glance and it looked OK. I am away this weekend but will review the PR properly and approve when I get back...
by kieranhj
Fri Oct 06, 2017 10:43 pm
Forum: projects
Topic: Starting a Prince of Persia port...
Replies: 129
Views: 7889

Re: Starting a Prince of Persia port...

I thought you would all like another weekend treat. This is the first level of the game fully playable including all secret areas! I ported the guard & AI functions, along with the ability to pick up objects including the sword. I also re-implemented the keyboard handler, so the game is actually...
by kieranhj
Thu Oct 05, 2017 4:13 pm
Forum: off-topic
Topic: Alternate Universe Micros...
Replies: 17
Views: 533

Re: Alternate Universe Micros...

Completely off-topic for this off-topic post (!!) but there are examples of fantasy computers being made as emulators, eg. https://www.lexaloffle.com/pico-8.php.

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