Search found 1378 matches

by Ast A. Moore
Sat Feb 22, 2020 5:56 pm
Forum: Programming
Topic: Building Screens
Replies: 11
Views: 310

Re: Building Screens

If I'm not mistaken, all the complexity you are referring to, derives from the fact that you are trying to use a single byte (8bit = 256 combinations) variable, instead of using a 16 bit one, for your horizontal position. Correct. But I actually refer to using fractional coordinates, so they are ef...
by Ast A. Moore
Sat Feb 22, 2020 5:42 pm
Forum: Games/Software
Topic: TauCeti
Replies: 3
Views: 88

Re: TauCeti

It’s pretty great, but I remember liking Academy even better. Can’t remember off the top of my head what the best strategy is, sorry.
by Ast A. Moore
Sat Feb 22, 2020 11:47 am
Forum: Programming
Topic: Music in-game Spec 48k
Replies: 2
Views: 74

Re: Music in-game Spec 48k

It’s next to impossible. The best example of the greatest amount of action on the screen while playing multichannel BEEPER music I can think of is the menu screen in Dark Fusion. That’s about as much as you can do.
by Ast A. Moore
Fri Feb 21, 2020 9:29 pm
Forum: Programming
Topic: Building Screens
Replies: 11
Views: 310

Re: Building Screens

I wonder why you say this ? Clipping to the left or right, is almost exactly the same. Not quite. Checking for the right-hand edge clipping is trivial and inexpensive. You simply increment the low byte of the screen address and AND it with $1f. If the result is zero, you skip drawing the next bit. ...
by Ast A. Moore
Fri Feb 21, 2020 6:01 pm
Forum: Programming
Topic: Building Screens
Replies: 11
Views: 310

Re: Building Screens

so if the sprite drawing over-runs a bit it's hidden by these border attributes. Indeed, that’s a cheep cop-out, but quite effective. I prefer not to do that, but then taking care of the clipping (especially of the left-hand edge of the screen) is a pretty involved, non-trivial task. Visually, quit...
by Ast A. Moore
Fri Feb 21, 2020 3:37 pm
Forum: Programming
Topic: Building Screens
Replies: 11
Views: 310

Re: Building Screens

I am sure there are many many benefits of the first routine, but are there real world uses for the second? Here’s something to keep in mind about the Spectrum (and many other 8-bit computers of the era): it’s extremely underpowered. For this reason, there are no universal approaches to coding (i.e....
by Ast A. Moore
Fri Feb 21, 2020 3:23 pm
Forum: Hardware
Topic: ZX Spectrum +2 tape deck not working.
Replies: 2
Views: 58

Re: ZX Spectrum +2 tape deck not working.

There’s a 5-pin connector on the right side of the logic board, which connects the tape deck’s amplifier to the computer. Take a look at it and make sure it’s seated properly. While you’re at it, you can take out the tape deck’s amp board and visually inspect it for sorts or broken connections. Chan...
by Ast A. Moore
Thu Feb 20, 2020 6:19 pm
Forum: Brand new software!
Topic: Trace It!
Replies: 14
Views: 507

Re: Trace It!

This is absolutely brilliant! Love the addition of inertia.
by Ast A. Moore
Tue Feb 18, 2020 12:06 am
Forum: Programming
Topic: Optimizing a Conditional (asm)
Replies: 4
Views: 228

Re: Optimizing a Conditional (asm)

Okay, not by way of helping (I’m pretty bad at this sort of math), but by way of making sure I understand your logic correctly, does this at least get the principle right? ld a,20 ld b,30 ld hl,integer_D sub b or a jp p,1$ neg 1$ cp (hl) jr nc,2$ xor b cp b jr nc,3$ sub (hl) ret 3$ add a,(hl) ret 2$...
by Ast A. Moore
Sun Feb 16, 2020 5:08 pm
Forum: Programming
Topic: Learning Machine Code
Replies: 36
Views: 1335

Re: Learning Machine Code

Hedge1970 wrote:
Sun Feb 16, 2020 4:11 pm
It just bails to basic if your cross is at the center.
Ah, makes sense!