Spectrum Computing

The original 48 manual, the grey +2 one and the +2A/+3 manuals are all great references.

The 48K+ and 128+ manual, by contrast, is barely more than a flimsy pamphlet and not much use at all.

To be honest though, very little of the 128K machines is much use in BASIC. You can access the extra memory via the RAMdisk commands, but they're inconsistent between the original 128/+2 and the later +2A/+3. They AY chip is accessible via PLAY, although that's not really a great implementation.

Excuse my ignorance, but what is the beam? I only ask because I am midway through building a routine that scrolls attributes both left and right but also up and down. The exact point on the screen that is actually being drawn by the CRT at any given moment. The picture is generated on the fly by th...

Good luck. It's a great game but absolutely rock hard. I think I made it to level 5 without any cheats, but I'd struggle to replicate that these days

Interesting I’ve been writing what each line does but actually the block is much better. Do you have any rules around the size of a block? Lots of people start out by commenting what literally every line does. And it's the worst thing ever. The code very quickly becomes swamped by comments and, bec...

Wall_Axe wrote: ↑Fri Feb 02, 2024 10:40 am Why didn't they use dithered red and white pixels for skin tone?

Usually because it means you have to have either white or red around the edges because of attributes and humans typically not being very square shaped.

Yeah, I think it's because it offers good contrast if the secondary colour is black, without feeling entirely colourless in the way a pure black/white version often does.

Ant Attack came out first and that had the benefit of actually good gameplay so I think the genre was already up and running. Both had crap controls though! Sure, but Ant Attack's shaded graphics looked primitive in comparison and all the rest of the presentation was a bit BASIC-esque. I'd played (...

I really don't like Atic Atac, too much 'fly swatting' for me. And yeah, now Knight Lore is like all the isometric 3D games I ever played, but hey, it was the first (um, Sandy White would like a word - Ed) and I've read recollections about it being seen as pure science fiction come to life. In the ...

There were a lot of full page ads for Renegade III in the magazines at the time. A lot. I'm not saying the reviews reflect that, but there sure were a lot of them.

PeteProdge wrote: ↑Wed Jan 31, 2024 10:05 am


Bet you feel silly now!

I'm more curious about what Betty Boo and the Bitmap Brothers have in common...

It's a bit hard to follow what you're actually trying to do. I'd have expected: LD HL, 8 ADD HL, DE EX HL,DE would be faster than looping 8 times incrementing DE. BUT why is DE incrementing anyway? Surely as you scroll the attributes your source pointer would change (i.e. the value in HL) but the de...

Contention happens only when the CPU is accessing the lower RAM. If the Z80 is held in a reset state then it won't access RAM and there would be no contention. If another device puts an address on the bus in order to access lower RAM, that surely will cause contention (although said device will nee...

If you hold RESET, won't you face issues with RAM failing to be refreshed?

IIRC if you just start a game of Bubble Dizzy and leave it alone, it'll run forever racking up.a huge score. Dizzy never runs out of oxygen because just enough bubbles spawn underneath you that your air supply continually replenishes.

Is that website getting theirs from Ali too? Makes a bit more sense I suppose. Easier on the wallet. I guess they won't say 'LEGO' on them then! Yeah, I had a dig through the site FAQs and it specifically says they aren't official Lego pieces and thus won't say Lego on them. It's also why they have...

Couldn't you just lower RAMTOP automatically? Surely it's not that difficult to find the entry point to the CLEAR routine?

One advantage to a Lego design is you could make it smaller and then redesign it any time you got bored of it. Assuming you get a roughly 50/50 split between black and orange pieces. A site that kits it up for you does look neat, although personally I couldn't bring myself to use unofficial pieces. ...

Also bear in mind that the signal put out by the Speccy is outside the PAL spec, so a very modern display might just struggle syncing with it directly.

From the Zilog docs;

Each cycle in the HALT state is a normal M1 (fetch) cycle except that the data received from the memory is ignored and an NOP instruction is forced internally to the CPU. The HALT acknowledge signal is active during this time indicating that the proces-sor is in the HALT state.

Oh well. I can dream! Looks like a wireless keyboard would do the job. Anyone have any luck attaching a USB wireless keyboard via a PS/2 adapter? https://i.postimg.cc/ygHKn14n/e91ea6e5-2955-4a8b-9a6f-6966416d185b-cropped.jpg I'm pretty sure USB keyboards and mice have to support the PS/2 protocol i...

I doubt there is one. Most of the genre stuff is a throwback to the old WoS flat file arrangement and I'm not sure consistency was ever its strong point. It's not a great way of representing that kind of data in the real world either. Generally I'd take the approach of allowing multiple "tags&q...

Batman The Movie has a great soundtrack, although I'd put the Batwing level as my favourite of all:

Here's a question: How come AY music sounds so different on the CPC from the Spectrum? Is there some kind of hardware filter or amplifier involved? Spectrum AY music often sounds thin and weedy like that Firefly tune, whereas the CPC seems fuller and more resonant, more arcadey in a way. The CPC ha...

Ah yes "!" vs "M" if I recall. As one bank is used by +3DOS , I wonder what happens with that on the +2A/B , if its got anything in it or used, as in for the ram-disk. It's the same. +3DOS still reserves some for a disk cache and keeps the second screen free regardless of whethe...