Spectrum Computing

Yeah, I didn't really expect it to be that feasible. With regard to counting T-states, I was planning on keeping every execution path the same length so that I know beforehand how long everything will take. The aim was basically to get a constant time sound loop that also accesses contended memory. ...

This is a problem I'm having with contention. I want to have some contended memory accesses, but they need to take the same number of T-states to complete each time, regardless of where the beam is on the screen when the access occurs. I can't sync to the 50Hz refresh using either interrupts or the ...

Nice work! The only thing I can think of is to look at the border colour (bits 0-2 on port $FE, but only with OUT) and see how it changes during the loading. Additionally, any even port will address the ULA, not just port $FE.

If you're doing regular AND-then-OR masking, you can just use OR B instead of CPL: AND B (and the same for C) as it doesn't matter what the mask is when the pixel value is set. That would get it down to 9 bytes. (EDIT: Actually in that case all you need to create the mask is a single DEC instruction...

Could you replace XOR 255 with CPL and get it down to 11 bytes?

Thanks, I got it working now. (I guess you meant to say to use the HOME key for an NMI?) The Pentagon timings are fine, but the samples are out of tune on a standard 128K, which doesn't happen on other emulators (e.g. Fuse). So it's just the 128 timings that are too fast.

Wow, this looks really nice. I'm impressed by the wealth of TV emulation options, and the tape deck is a nice touch too. For some reason the AY chip is clocked around 5% faster than normal, but otherwise it seems to be quite accurate. :shock: What game have you noticed this in?. RVM 1/2 works a lit...

Wow, this looks really nice. I'm impressed by the wealth of TV emulation options, and the tape deck is a nice touch too.

For some reason the AY chip is clocked around 5% faster than normal, but otherwise it seems to be quite accurate.

There are games on the PC that use non-square pixels. For example, Doom draws to a 16:10 framebuffer, which is stretched up to 4:3 by the monitor: https://doomwiki.org/wiki/Aspect_ratio . As long as you design all the graphics with that in mind you shouldn't necessarily need to alter the framebuffer...

Thanks everyone for another great collection! The magazine is really funny, I especially enjoyed the interview.

I did notice a serious error where someone misspelled "Zythum, by Mirrorsoft" at the beginning of side 2.

Just to note, a couple of things to watch out for in VT 2.5 are the "Envelope as Note" and "Decimal for Noise Level in pattern and sample" options. I don't recommend saving your song with either of them enabled, as it will get corrupted if you use envelope notes lower than C-1 or...

I haven't donated sorry, but thanks for posting this. It's a cool game with quite a surreal setting and atmosphere, and it's worth checking this one out.

That Las Llaves is a great idea for a game, and nicely executed too. Although I did find it annoying ending up stuck in the same dead end room again and having to reRUN the program, even when trying to avoid it! I'm sure it would be possible to make a random level generator for it and maybe even add...

I just remembered the infamous driving section in A View to a Kill which had some kind of 3D walls, but rather slowly and only at 90 degree angles.

Something like Wacky Wheels on the Spectrum would be cool. Days of Thunder uses simple vector graphics for the track, and the speed is quite good when turning corners, although some of that may be precalculated so it might not be a good example. Scrolling the background scenery slows it down a bit s...

If you turn the TV/monitor sideways you could get a nice horizontal scroller.

The crash I got might have been something different, but I wasn't counting levels. Here's an RZX of it occurring if it helps: OldTowerCrash.rzx EDIT: The crash occurs because of a LD (BC), A instruction at $FBD4 that takes out the interrupt handler when BC == $BFBF. I think the LD (BC), A is put the...

Amazing game with great graphics, sound and some of the smoothest scrolling I've seen. The only trouble I've run into so far is that it isn't really clear you can only change characters if they're oriented in certain directions (not facing the other one). I experienced a reset after finishing one of...

Thanks, the Sabre Wulf code would be useful to look at. I've located the main loop which does happen to be a series of CALLs, and I've found some addresses for the enemy structures. This game has some quite odd code in places, such as using a loop of LDI: DJNZ to draw the sprite rows even though the...

Here's what I've managed so far. Still need to get the rooms to remain synchronised and prevent the enemies attacking the player in inactive rooms.



I noticed that BRIGHT colours don't work for some reason, is that just something on my end?

Thanks, I've got a build working now and found the room address, so I'll see if I can make any progress on this.

Can this work for games where enemies and objects move between the rooms? I've got a game in mind that I'd be interested in porting with this if it's possible.

Rorthron wrote: ↑Thu Nov 01, 2018 8:32 am The ad for Blackbox mentions a board printout facility. Does the recovered file have this? (I can't check myself right now.)

Not one that I can see from a quick look at the listing. The ad also mentions 16K Spectrums while this game seems to be 48K only (11175 bytes on tape).

There was also a version of this game as a listing in YS: https://archive.org/details/your-spectrum-magazine-13/page/n61 https://archive.org/details/your-spectrum-magazine-17/page/n21 Good find! Would you be able to look at the code and see if it matches? Interesting that type-in is not in the arch...

There was also a version of this game as a listing in YS:

https://archive.org/details/your-spectr ... 3/page/n61
https://archive.org/details/your-spectr ... 7/page/n21