Search found 478 matches

by PROSM
Thu May 16, 2024 8:58 pm
Forum: Design/Ideas
Topic: Suggestion :Developers please try to also create Appimages for linux
Replies: 35
Views: 773

Re: Suggestion :Developers please try to also create Appimages for linux

Linux is infinitely customizable, which is great if that's what you want. But it's terrible from a developer perspective where you can't entirely rely on anything being available - even really basic stuff like how the audio stack works. Appimages try to fix that but it's just too vast a chasm to en...
by PROSM
Fri May 10, 2024 6:55 pm
Forum: Design/Ideas
Topic: Honestly, this is more of an idea to myself, but what if IWBTG was on the Speccy?
Replies: 22
Views: 504

Re: Honestly, this is more of an idea to myself, but what if IWBTG was on the Speccy?

Lee Bee wrote: Fri May 10, 2024 12:34 pm [...] Though not as cruel as "World's Hardest Game" - another awesome title that would be fun to convert to the Speccy. [...]
We've already got it, ported in 2014 by Trefi and Tiboh: https://spectrumcomputing.co.uk/entry/30073 :)
by PROSM
Wed Apr 10, 2024 4:29 pm
Forum: Other Retro Stuff
Topic: any suggestion for a good portable device that can play zx spectrum games?
Replies: 10
Views: 1040

Re: any suggestion for a good portable device that can play zx spectrum games?

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...
by PROSM
Tue Apr 09, 2024 8:27 pm
Forum: Programming
Topic: Kempston support
Replies: 16
Views: 474

Re: Kempston support

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...
by PROSM
Sun Mar 31, 2024 5:53 pm
Forum: Programming
Topic: Zilog's Z80 opcode choice
Replies: 20
Views: 682

Re: Zilog's Z80 opcode choice

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...
by PROSM
Thu Mar 28, 2024 4:24 pm
Forum: Other Retro Stuff
Topic: any suggestion for a good portable device that can play zx spectrum games?
Replies: 10
Views: 1040

Re: any suggestion for a good portable device that can play zx spectrum games?

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 ...
by PROSM
Mon Mar 25, 2024 11:42 am
Forum: Games/Software
Topic: A 16K/48K/128K Spectrum game?
Replies: 6
Views: 633

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

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.
by PROSM
Mon Mar 11, 2024 12:42 am
Forum: Programming
Topic: Multiplying routine in assembler
Replies: 6
Views: 737

Re: Multiplying routine in assembler

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...
by PROSM
Sat Mar 09, 2024 10:20 am
Forum: Programming
Topic: Measuring frames/VSYNC
Replies: 10
Views: 823

Re: Measuring frames/VSYNC

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...
by PROSM
Tue Mar 05, 2024 7:22 am
Forum: Sinclair Miscellaneous
Topic: That thing with the blue and magenta ladders (OUT)
Replies: 39
Views: 1560

Re: That thing with the blue and magenta ladders (OUT)

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...
by PROSM
Tue Mar 05, 2024 7:07 am
Forum: Sinclair Miscellaneous
Topic: That thing with the blue and magenta ladders (OUT)
Replies: 39
Views: 1560

Re: That thing with the blue and magenta ladders (OUT)

equinox wrote: Tue Mar 05, 2024 7:03 am I would love a screenshot actually.
Sure, here it is:

Image

Not quite how you depicted it, but close.
by PROSM
Tue Mar 05, 2024 6:57 am
Forum: Sinclair Miscellaneous
Topic: That thing with the blue and magenta ladders (OUT)
Replies: 39
Views: 1560

Re: That thing with the blue and magenta ladders (OUT)

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...
by PROSM
Fri Mar 01, 2024 11:30 pm
Forum: Games/Software
Topic: Could Knight Lore have been (a lot) faster?
Replies: 10
Views: 559

Re: Could Knight Lore have been (a lot) faster?

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 ...
by PROSM
Fri Mar 01, 2024 10:30 am
Forum: Games/Software
Topic: Branding in games
Replies: 20
Views: 657

Re: Branding in games

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.
by PROSM
Tue Feb 27, 2024 7:50 am
Forum: Programming
Topic: Bank 7 corruption while loading in Plus2A mode
Replies: 9
Views: 558

Re: Bank 7 corruption while loading in Plus2A mode

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...
by PROSM
Sun Feb 25, 2024 7:53 pm
Forum: Other Retro Stuff
Topic: Introducing retro gaming to my lad
Replies: 8
Views: 624

Re: Introducing retro gaming to my lad

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...
by PROSM
Fri Feb 23, 2024 3:01 pm
Forum: Games/Software
Topic: Games that made good use of FLASH
Replies: 26
Views: 1667

Re: Games that made good use of FLASH

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

by PROSM
Wed Feb 21, 2024 6:30 pm
Forum: Games/Software
Topic: Guess the screen$
Replies: 8051
Views: 255114

Re: Guess the screen$

Flippin' heck, that was quick! :shock: Yes, it is indeed Luna Crabs. Back to you, @stupidget!
by PROSM
Wed Feb 21, 2024 6:15 pm
Forum: Games/Software
Topic: Guess the screen$
Replies: 8051
Views: 255114

Re: Guess the screen$

I thought the frame looked a little familiar...

Anyway, try this one:

Image
by PROSM
Wed Feb 21, 2024 3:31 pm
Forum: Games/Software
Topic: Guess the screen$
Replies: 8051
Views: 255114

Re: Guess the screen$

Flunky?
by PROSM
Thu Feb 15, 2024 9:25 am
Forum: Games/Software
Topic: How big should new Speccy games be? 48k? Bigger? Release 2 versions?
Replies: 67
Views: 2436

Re: How big should new Speccy games be? 48k? Bigger? Release 2 versions?

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...
by PROSM
Mon Feb 12, 2024 10:22 am
Forum: Brand new software!
Topic: Pacman Begins
Replies: 25
Views: 1162

Re: Pacman Begins

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...
by PROSM
Sun Feb 11, 2024 6:09 pm
Forum: Brand new software!
Topic: ZagZag 256b game
Replies: 2
Views: 335

Re: ZagZag 256b game

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.
by PROSM
Sun Feb 11, 2024 5:57 pm
Forum: Brand new software!
Topic: Pacman Begins
Replies: 25
Views: 1162

Re: Pacman Begins

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...
by PROSM
Sat Feb 10, 2024 11:12 am
Forum: Brand new software!
Topic: Pacman Begins
Replies: 25
Views: 1162

Re: Pacman Begins

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.