Search found 84 matches

by dfzx
Mon Jul 23, 2018 7:37 am
Forum: Programming
Topic: An impressive way to crash the Speccy?
Replies: 8
Views: 153

Re: An impressive way to crash the Speccy?

The first year that I got my hands on a Speccy, when I had got my head around the normal BASIC commands and functions, I started playing with POKE and USR. I tried many combinations in the search for useful or interesting effects. I used to do the same thing. I still have "RANDOMISE USR 2272" commi...
by dfzx
Thu Jul 05, 2018 8:04 am
Forum: Games/Software
Topic: Games for Spectrum+
Replies: 8
Views: 189

Re: Games for Spectrum+

The Spectrum+ was released about 2 years after the original rubber key model. Internally it's the same machine as the 48K, only with a "better" case and keyboard, so any software you find for a 48K will work on your Spectrum+. The 128K, +2 and +3 models came later and are very different to the 48K. ...
by dfzx
Sat Jun 23, 2018 4:17 pm
Forum: Sinclair Miscellaneous
Topic: Clive Sinclair: hero or zero?
Replies: 51
Views: 1259

Re: Clive Sinclair: hero or zero?

Despite the hatchet job some people are dishing out based on 20/20 hindsight, Sir Clive will always be a hero for me. He changed my life when I was 13 years old, and went on to change the world, in almost every way for the better. He's done so without doing a great deal of harm to anyone, and not ma...
by dfzx
Wed Jun 13, 2018 11:58 am
Forum: Programming
Topic: Z80 interrupt sequence
Replies: 2
Views: 152

Re: Z80 interrupt sequence

Joefish wrote:
Wed Jun 13, 2018 10:39 am
So if your ISR always does EI then RET at the end, then the answer is 'Yes'. You can just use HALT whenever you like.
Yes, the ISR re-enables the interrupt when it exits. So, all good, thanks. :)
by dfzx
Wed Jun 13, 2018 9:36 am
Forum: Programming
Topic: Z80 interrupt sequence
Replies: 2
Views: 152

Z80 interrupt sequence

If I have code which logically looks like this: isr() { stuff.. } main() { ... x=0 halt x=1 ... } am I guaranteed that 'stuff' will be called and execute to completion before x goes to 1? My reading of the Z80 manual says that it will, but I'm not sure the halt and interrupt response parts are cryst...
by dfzx
Sun Jun 10, 2018 2:25 pm
Forum: Showcase your work!
Topic: z88dk documentation series, installment 8: interrupts
Replies: 6
Views: 359

Re: z88dk documentation series, installment 8: interrupts

I'm very much looking forward to reading about collisions @dfzx in a future installment. :lol: you might have to wait a while for that one. I haven't the faintest idea how to do it! Mind you, that's been my starting point with every topic I've covered so far. Who'd have thought, 35 years after I fi...
by dfzx
Sun Jun 10, 2018 2:05 pm
Forum: Showcase your work!
Topic: z88dk documentation series, installment 8: interrupts
Replies: 6
Views: 359

Re: z88dk documentation series, installment 8: interrupts

Thanks Peter. You're right, they're a lot of work, and I'm aware my readership can probably be counted on my fingers. :) Thing is, I really believe that 'C' is an immensely practical and desperately underused language on the Spectrum. It's close to assembly language in performance, and development w...
by dfzx
Sun Jun 10, 2018 10:19 am
Forum: Showcase your work!
Topic: z88dk documentation series, installment 8: interrupts
Replies: 6
Views: 359

Re: z88dk documentation series, installment 8: interrupts

Another 'C' and SP1 article is up:

https://github.com/z88dk/z88dk/blob/mas ... Sprites.md

This covers bigger sprites and adding colour to them.
by dfzx
Fri Jun 01, 2018 7:26 pm
Forum: Emulators
Topic: Advice on the sweet setup for programming on the Speccy.
Replies: 17
Views: 698

Re: Advice on the sweet setup for programming on the Speccy.

The problem is that I have never seen a good game written with these Basic dialects. Actually I haven't seen much games at all written with them, don't believe any of them really caught on. The thing about those extended BASICs, at least for me, is that they extended what the Spectrum's native BASI...
by dfzx
Fri Jun 01, 2018 11:20 am
Forum: Emulators
Topic: Advice on the sweet setup for programming on the Speccy.
Replies: 17
Views: 698

Re: Advice on the sweet setup for programming on the Speccy.

My private opinion is that these extended versions existing in the 80s didn't give you much more than standard one and there was much nuissance with loading and saving your programs. Bit harsh, Ralf. :) White Lightning was Forth based, and from what I recall it did funky things (presumably with int...