Spectrum Computing

Guessing you need to homebrew crack your 3DS for that to work though. Whereas an R4 card can boot on a standard handheld. Yes, you do need to mod the 3DS, but it seems to be quite easy these days - there's a comprehensive website which guides you steo-by-step (not linking directly to it due to foru...

For the Kempston, you read from port 31. The received byte is as follows: 000FUDLR (F - fire, U - up, D - down, L - left, R - right) The Kempston joystick input is active-high, meaning that if the button/direction is activated, the relevant bit will be 1. This is in contrast to the keyboard, which i...

Having LD A,A and so on is an 8080 design choice, and the Z80 designers had to keep it that way for compatibility's sake, since they were official instructions. The new Z80 instructions and prefixes replaced the undocumented opcodes of the 8080, which were all alternative encodings of documented ins...

If you can get hold of one for a good price, then something from the Nintendo DS range would make a decent little console, when paired with an inexpensive flashcart and Patrik Rak's ZXDS emulator. Flashcarts tend to cost about £9 on the UK market, and you'll need a microSD card to store its data on ...

Pobulous wrote: ↑Mon Mar 25, 2024 9:08 am Has there even been a game that was different on 16K and 48K?

E.T.X. will run on both 16/48K, and adds sampled speech for 48K owners.

I saw this page today while I was looking for a fast multiply by various constants... wasn't what I was looking for but this uses a 512 byte lookup table and is 90T states by my reckoning, so very fast. But it only works for multiplying numbers in the range -64 to +63 looks like (listing at the end...

The common way to synchronise the Z80 with the raster beam is just to do a HALT - this stops the Z80 until the next interrupt is received, at which point it runs the interrupt service routine and then continues with the main program. The ULA (the Spectrum's central chip which handles video, sound, k...

What repeating pattern are we seeing, in the Spectrum brain? Here's the first 256 bytes or so, as viewed in a hex editor: Hex View 00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F 00000000 5B 38 00 00 5B 48 00 38 00 0D 5B 38 00 00 5B 48 [8..[H.8..[8..[H 00000010 00 38 00 0D 5B 38 00 00 5B 48 00 38 0...

equinox wrote: ↑Tue Mar 05, 2024 7:03 am I would love a screenshot actually.

Sure, here it is:



Not quite how you depicted it, but close.

As Andy says, a random OUT doesn't cause this directly, but rather it is the catalyst for the effects you describe. The memory paging register on the 128K machine is usually accessed via port $7FFD. However, this port address is only partially decoded - the hardware only checks that A15 and A1 are 0...

It probably could have been faster, with the benefit of hindsight. There were some insightful posts recently in the "Ultimate Filmation Maths" thread, written by what_the_wasabi and quoted below: Apologies for resurrecting this thread but it came up when searching for Filmation. I've been ...

The only one that springs to mind right now is Weetabix Versus the Titchies, priced at £3.75, or £2.75 if you were a member of the Weetabix Club.

As zup says, the easiest way is to disable interrupts or use interrupt mode 2 with your own routine. If you need to use the ROM interrupt routine, and don't want to make the user have to load it in USR0 mode, then what you need to do as soon as your loader starts is switch to the 48K ROM (ROM3), and...

I saw the ridiculously cheap Ali items and I am tempted buuuut if if doesn't have Mario then it'll be bottom of the toy cupboard :? Assuming that it's identical to the one in this review , it does include at least Super Mario Brothers 1 and 3. Bear in mind that some graphics could be altered for re...

Just found another one - the Hong Kong level from Travel with Trashman.

Flippin' heck, that was quick! Yes, it is indeed Luna Crabs. Back to you, @stupidget!

I thought the frame looked a little familiar...

Anyway, try this one:

Flunky?

The Speccy gets more than it's fair share of "ambitious" titles, with things like Castlevania, Seraphina and Sword of Ianna. But those titles are a lot of effort for the coders in particular,l and the interesting coding tends to make up only a tiny percentage of that, so most of it can be...

Was aiming just to pip Lee's score, and ended up with... https://i.postimg.cc/ZqM3LLCQ/pacman-begins-195600-12-02-24.png 195600 ... Your turn, Andre :mrgreen: Once you have the technique down, it's more a case of trying to maintain concentration than anything else. After I was past the slight jitter...

Cool little game, reminds me of the similarly small Line. Thanks for including the source code too, always good for picking up new optimisation tricks.

https://i.postimg.cc/MX8DMd2C/pacman-begins-45100-2023-02-11.png 45100 - a new personal best. I've just started to figure out the strategy for getting the red ghost right up against the opposite screen edge when there's some pellets still in the centre, but the issue is putting that into practice w...

Great one-key game! As others have said, the attention to detail is what really makes it special. I've managed up to 18420 so far, but keep ending up tapping Space twice instead of once, sending me straight into the ghost.

As you say, hopefully whoever wins the first one will preserve it. The second one, unfortunately, is likely to just fester in the seller's house, because nobody in their right mind is going to buy it for that much. Unfortunately, while a good portion of people who possess these rarities will share t...

As far as I know, guests can search every 30 seconds, and logged-in users every 10 seconds (see https://spectrumcomputing.co.uk/forums/viewtopic.php?p=106540 ). It can be annoying to wait when you want to retype something or get the next page of results (I know I've had enough trouble with it when t...