Search found 467 matches

by stefano
Thu Jun 24, 2021 8:59 pm
Forum: Spectrum BASIC
Topic: usage of def fn in basic
Replies: 3
Views: 16018

Re: usage of def fn in basic

there is even an interesting trick to even use DEF FN recursively, IIRC using VAL cleverly to enable the recursion only up to desired result.
by stefano
Thu Jun 24, 2021 10:51 am
Forum: GAMES
Topic: Remake of an ancient board game
Replies: 23
Views: 1225

Re: Remake of an ancient board game

I checked the code and I couldn't find reasons for the behavior you were describing, but for a very bad position of the unexpected bad events, now improved. I tend to believe that you were trapped in an improbable but still possible chain of bad events. In my tests I never got a dry hole, though.. s...
by stefano
Mon Jun 21, 2021 11:09 pm
Forum: ZX BASIC
Topic: SCROLL and ZxPrinter bug.
Replies: 6
Views: 1386

Re: SCROLL and ZxPrinter bug.

Is the collapsed D-FILE making the COPY command fail also without the SCROLL interference?
by stefano
Mon Jun 21, 2021 7:39 pm
Forum: GAMES
Topic: Remake of an ancient board game
Replies: 23
Views: 1225

Re: Remake of an ancient board game

wow. there are accidents which might cause a similar condition (loss of both pipeline and refinery) but it should warn you and it's not expected to happen everytime :roll:
I'll check
by stefano
Mon Jun 21, 2021 9:14 am
Forum: GAMES
Topic: Remake of an ancient board game
Replies: 23
Views: 1225

Re: Remake of an ancient board game

This is, in my intention, the final version. I updated the files of my previous post. I found the game instructions online and fixed a relevant number of serious bugs which were present in the original ZX Spectrum version ! The game is now more difficult (but still playable). The difficulty level no...
by stefano
Sun Jun 20, 2021 10:09 pm
Forum: Software
Topic: Pascal for ZX81
Replies: 28
Views: 3993

Re: Pascal for ZX81

well, if it has a p-code (or similar interpreter), that is definitely interesting :)
by stefano
Sun Jun 20, 2021 7:45 pm
Forum: ZX BASIC
Topic: SCROLL and ZxPrinter bug.
Replies: 6
Views: 1386

Re: SCROLL and ZxPrinter bug.

0869 COPY LD D,+16
LD HL,+D-FILE
INC HL
JR 0876,COPY*D

16 hex=22 text lines. By the way, the collapsed D-FILE includes all the text line terminations.
I don't see the bug, in the code.. yet it's not the simpler routine :D
by stefano
Sun Jun 20, 2021 7:30 pm
Forum: ZX BASIC
Topic: SCROLL and ZxPrinter bug.
Replies: 6
Views: 1386

Re: SCROLL and ZxPrinter bug.

Uh, I studied the copy routine and I never thought at this limit. The ZX Printer and compatibles need a precise timing to sync the data to be outputted and the printing needle, I'm quite sure that even the tractor feed deceleration is compensated in the program loop (every 8 dot lines, thus a full t...
by stefano
Sun Jun 20, 2021 1:34 pm
Forum: Development
Topic: Idea for a custom old school soundboard
Replies: 0
Views: 127

Idea for a custom old school soundboard

I understand the eighties market was mostly represented by the ym chip. Then even better hardware was introduced, so perhaps it's not surprising that other traditional electronics tricks were limited for door bell circuits etc. In some limited case in the earlier computers something was done, especi...
by stefano
Sun Jun 20, 2021 1:27 pm
Forum: Development
Topic: Let's talk about Hi-Res truth and myths, I'm angry.
Replies: 6
Views: 560

Re: Let's talk about Hi-Res truth and myths, I'm angry.

beware, the zx81 video generation topic is a very complex one, the zx81 does it with a clever mixture of hardware and low level software tricks, in many cases it is not for free, either you bend the hardware, or the ROM, or you need lots of ram space.. or all of the above :)