Search found 1406 matches

by AndyC
Fri Apr 19, 2024 8:37 am
Forum: Other Retro Stuff
Topic: Any CPC Wiki forum users?
Replies: 4
Views: 155

Re: Any CPC Wiki forum users?

Yeah, was working fine for me this morning. Bit slow occasionally but that's not abnormal.
by AndyC
Thu Apr 18, 2024 8:38 am
Forum: Games/Software
Topic: Something I noticed about Renegade 3
Replies: 12
Views: 499

Re: Something I noticed about Renegade 3

Those rating it >5, how do you rate Double Dragon? I've never entirely understood the hate DD on the Speccy gets. Me and my sister loved it as kids, as one of the few co-op games we had. The multiload was a bit punishing on 48K but it was still fun. I can understand that the graphics have a differe...
by AndyC
Wed Apr 17, 2024 2:43 pm
Forum: Games/Software
Topic: Something I noticed about Renegade 3
Replies: 12
Views: 499

Re: Something I noticed about Renegade 3

Without the Renegade title and without the ridiculous time limit, it'd be a solid 6/10 budget game. With both of those and at full price, it fully deserved to be slated.
by AndyC
Sun Apr 14, 2024 1:52 pm
Forum: Games/Software
Topic: The best playable demo of a budget game on a YS/Crash/SU covertape: vote
Replies: 6
Views: 300

Re: The best playable demo of a budget game on a YS/Crash/SU covertape: vote

I loved Dizzy and his many sequels, so they'd easily take the top spot, except I'm applying my own arbitrary rules again that I actually have to remember the demo and not the full game so they're out of the running. So with those completely nonsense rules in place: 1) Steg the slug - an underrated g...
by AndyC
Sun Apr 14, 2024 11:15 am
Forum: Programming
Topic: Bank switching issue
Replies: 32
Views: 1087

Re: Bank switching issue

also note that by destroying sysvars you won't be able to use +3DOS. you need to call ROM interrupt handler to eventually turn drive motor off, and it uses some other sysvars too. tbh, i never bothered to get rid of sysvars, and i don't think you need to. ;-) hey, you wasted 257 bytes on interrupt ...
by AndyC
Fri Apr 12, 2024 9:10 pm
Forum: Sinclair Miscellaneous
Topic: New forum game -- Spectrum graphics in the real world?
Replies: 145
Views: 5532

Re: New forum game -- Spectrum graphics in the real world?

Image

Terrible photography, but familiar nonetheless
by AndyC
Fri Apr 12, 2024 12:56 pm
Forum: Programming
Topic: Data prior to the default UDG bank
Replies: 15
Views: 314

Re: Data prior to the default UDG bank

Would popping the registers off the stack between levels help? If you're writing "clean" code, the number of things you PUSH and POP should always align (not that CALL is also a PUSH and RET is also a POP) in such circumstances. So you should be reasonably confident that your stack is in ...
by AndyC
Thu Apr 11, 2024 6:28 pm
Forum: Hardware
Topic: Purely theoretical ROM swap
Replies: 7
Views: 279

Re: Purely theoretical ROM swap

I mean, you could probably find out exactly by just supplying a zx81 ROM image into a spectrum emulator. It won't be very useful regardless, because the zx81 ROM will have absolutely no idea how to drive the screen or poll the keyboard, it'll just fill RAM up with garbage and sit around waiting.
by AndyC
Tue Apr 09, 2024 7:37 am
Forum: Other Retro Stuff
Topic: Lara Croft voted most iconic character ever
Replies: 42
Views: 903

Re: Lara Croft voted most iconic character ever

It's been also said about Master Chief earlier, but tbh I'm not sure where does this notion come from. Both these characters have very strong identity, (visual, at least) and the fact that they don't say much or that MC is wearing a helmet doesn't stop me (and clearly a lot of other people) from re...
by AndyC
Mon Apr 08, 2024 5:40 pm
Forum: Games/Software
Topic: The best playable demo of a full price game on a YS/Crash/SU covertape: vote
Replies: 45
Views: 838

Re: The best playable demo of a full price game on a YS/Crash/SU covertape: vote

goodboy wrote: Mon Apr 08, 2024 5:30 pm the shadow of the beast also belongs to this category, she's not playable
Some would say the same of the final game.... :lol:
by AndyC
Sun Apr 07, 2024 10:17 am
Forum: Games/Software
Topic: The best playable demo of a full price game on a YS/Crash/SU covertape: vote
Replies: 45
Views: 838

Re: The best playable demo of a full price game on a YS/Crash/SU covertape: vote

It's very hard, so I've tried to stick to games I remember playing the demos of back in the day and enjoying. Which, to some extent, excludes those I bought the game of because I'll have forgotten the demo but hey ho. 1) Dominator - I remember loading this one, lots. As a massive R-Type fan I loved ...
by AndyC
Sat Apr 06, 2024 2:37 pm
Forum: Other Retro Stuff
Topic: Lara Croft voted most iconic character ever
Replies: 42
Views: 903

Re: Lara Croft voted most iconic character ever

I may have shot down my own arguments here. Just asked my girlfriend - who is not a gamer unless you count The Sims or those rollercoaster games - to name a videogame character. Without the slightest pause: "Lara Croft". Can't say I'm surprised, I think some people here have a very skewed...
by AndyC
Thu Apr 04, 2024 9:24 am
Forum: Programming
Topic: Bank switching issue
Replies: 32
Views: 1087

Re: Bank switching issue

you prolly have the stack somewhere around $FF00, or something. so when you switched the banks, the window [$C000..$FFFF] moved to another memory region… and your stack stays in the old one. ;-) just remember that memory area [$C000..$FFFF] is affected by switch, and design your code around that. I...
by AndyC
Wed Apr 03, 2024 8:28 am
Forum: Showcase your work!
Topic: Abersoft fig-Forth Recompiled
Replies: 108
Views: 1862

Re: Abersoft fig-Forth Recompiled

this will limit the ways to use the system. the idea is that you can move the sprites anywhere in your code, when you want it, not when the system wants you to do it. you command — the system obeys, not vice versa. ;-) Doing this in interrupts will make the code exponentially harder to use. Because...
by AndyC
Tue Apr 02, 2024 3:18 pm
Forum: Programming
Topic: Bank switching issue
Replies: 32
Views: 1087

Re: Bank switching issue

I bet you still have interrupts enabled? If you do, you need to update the relevant system variables before you switch banks. If you don't do that, there is every chance the system will sweep in when you're not looking, do some stuff and then "restore" the correct banking as per the variab...
by AndyC
Sun Mar 31, 2024 7:05 pm
Forum: Programming
Topic: Zilog's Z80 opcode choice
Replies: 20
Views: 518

Re: Zilog's Z80 opcode choice

Honestly I don't think it's the prefixes I'd be bothered about. If I wanted to tweak the Z80 design, removing the need to re-read instructions like LDIR would've been where I'd go next. And maybe redesign instructions like OTIR to be better suited to a 16-bit IO range (use DE as the destination rath...
by AndyC
Sun Mar 31, 2024 1:29 pm
Forum: Programming
Topic: Zilog's Z80 opcode choice
Replies: 20
Views: 518

Re: Zilog's Z80 opcode choice

DEC SP/INC SP are silly instructions too. It would be loads better if it decremented/incremented by 2, changing by 1 has no use I can think of, since you always push a word to the stack. If it incremented by 2 it would just be like discarding the value on the top of the stack (I usually use POP AF ...
by AndyC
Sat Mar 30, 2024 11:14 pm
Forum: Programming
Topic: Zilog's Z80 opcode choice
Replies: 20
Views: 518

Re: Zilog's Z80 opcode choice

Well, the decision was mostly made for them. A design goal of the Z80 was to be able to run all 8080 code at a binary level, so you couldn't really just swap out less used instructions even if you wanted to. Whether that was really necessary is a different question I suspect the actual instruction s...
by AndyC
Thu Mar 28, 2024 1:18 pm
Forum: Games/Software
Topic: Starglider being used to gunge children on telly in 1987
Replies: 8
Views: 234

Re: Starglider being used to gunge children on telly in 1987

Yeah, I've heard that said and I didn't actually mean to drive down there, it's just that an incident with my car meant I had to stop in Norwich city centre for a while and when I resumed going to my actual destination, I saw myself heading down that very road. Even though it was a Thursday afterno...
by AndyC
Thu Mar 28, 2024 9:49 am
Forum: Games/Software
Topic: Starglider being used to gunge children on telly in 1987
Replies: 8
Views: 234

Re: Starglider being used to gunge children on telly in 1987

Almost certainly Amigas. From what I hear of Barcadia, you have to pay £10 for a bunch of American quarters, which gets you about 10 goes on the arcade machines, it's also located on probably the worst street for dealing with drunk clubbing types. Meanwhile, five minutes away there is an arcade in t...
by AndyC
Wed Mar 27, 2024 7:38 pm
Forum: Hardware
Topic: Whitby Computers Spectrum Simulator for C64
Replies: 1
Views: 170

Re: Whitby Computers Spectrum Simulator for C64

Ah, so a hand coded reimplementation of the Speccy ROM in 6502. I'd have guessed it had to be something like that to function at any kind of speed, actually emulating a Z80 would've been a very tall order. Impressive that he also got it loading actual ZX tapes via the C64's slightly weird tape syste...
by AndyC
Tue Mar 26, 2024 8:36 am
Forum: Sinclair Miscellaneous
Topic: DenOfGeek : The games that defined the Spectrum
Replies: 31
Views: 672

Re: DenOfGeek : The games that defined the Spectrum

There are also Dizzy (Amstrad CPC) If you look at the internals of Dizzy, it's pretty obvious the primary target platform was the Spectrum. The CPC version stores all the colour numbers in Spectrum format and then remaps them onto its 4 colour mode (this is why there are no blue background objects,...
by AndyC
Mon Mar 25, 2024 9:29 am
Forum: Games/Software
Topic: A 16K/48K/128K Spectrum game?
Replies: 6
Views: 287

Re: A 16K/48K/128K Spectrum game?

Honestly, I'd have thought the requirements for running in just 16K (tiny amount of RAM, can't use IM2 etc) would make such a thing extremely unlikely and little more than a proof of concept if it did exist. I can't even remember games that would be expanded on a 48K machine, I think the prevalence ...
by AndyC
Wed Mar 20, 2024 2:00 pm
Forum: Programming
Topic: Progamming with Chatgpt 4/ copilot
Replies: 13
Views: 410

Re: Progamming with Chatgpt 4/ copilot

Ultimately ChatGPT (and all LLMs) is essentially predictive text on steroids. It's very, very good at generating plausible looking text but it never actually understands what it is doing. It's why it might get a long way to producing vaguely correct code, especially in boilerplate scenarios, but it'...
by AndyC
Tue Mar 19, 2024 8:03 pm
Forum: Programming
Topic: ZX Spectrum Emu - Booting issue
Replies: 2
Views: 140

Re: ZX Spectrum Emu - Booting issue

I've only had a quick squint at the code, but can't quite see how your interrupts are supposed to work. halt seems to set an internal variable but I can't see where it is used. The actual implementation of maskable interrupts seems to be inside an nmi function (which seems weird) but I can't see whe...