Search found 1165 matches

by dr beep
Tue May 14, 2019 9:16 pm
Forum: Development
Topic: Code optimization, an example
Replies: 0
Views: 141

Code optimization, an example

Suppose you want to read the keyboard key by key and know what key is pressed You can use this code to get that result. wup ld a,(lastk) ; 03 inc a ; 04 test keyup jr nz,wup ; 06 wdown ld bc,(lastk) ; 10 bc needs IN and IN-result from lastk to translate ld a,c ; 11 inc a ; 12 test keydown, no key wh...
by dr beep
Mon May 13, 2019 3:29 pm
Forum: GAMES
Topic: New ZX81 Games
Replies: 136
Views: 83783

New ZX81 Games : Lingo

Name of Software: Lingo Author: Johan "Dr Beep" Koelman Release Date: 13/05/2019 Requirements (eg. 1K, 16K, AY Card, Hi-Res Scheme): 1K lowres Description: Guess all 242 words stacked in this wordgame lingo.png Download link (if available for download): Lingo.p Commercial / Public Domain / Freeware ...
by dr beep
Tue May 07, 2019 9:55 pm
Forum: GAMES
Topic: Asteroids
Replies: 1
Views: 167

Re: Asteroids

Keep coding and you will reach this level.
https://m.youtube.com/watch?v=HtIS2OUIF ... ex=14&t=0s
by dr beep
Sat Apr 27, 2019 5:18 pm
Forum: Emulators
Topic: bugs found on eo
Replies: 14
Views: 1925

Re: bugs found on eo

So it is a bug in ZX Spin.
by dr beep
Sat Apr 27, 2019 4:32 pm
Forum: Emulators
Topic: bugs found on eo
Replies: 14
Views: 1925

Re: bugs found on eo

Is opcode 9 wrong in emulation?

I tried same code in EightyOne and on ZX Spin.

LD HL,#FAFF
LD BC,#501
ADD HL,BC

RET Z

In EightyOne the Z-flag is not set when result is #100000 (1 goes to C-flag, but HL becomes 0, thus Z is set)
bug_EO.png
by dr beep
Sun Apr 21, 2019 11:35 am
Forum: Emulators
Topic: bugs found on eo
Replies: 14
Views: 1925

Re: bugs found on eo

Looks like all versions were corrupt somehow. Altered the code a bit.
Now working.
by dr beep
Sun Apr 21, 2019 11:29 am
Forum: Emulators
Topic: bugs found on eo
Replies: 14
Views: 1925

Re: bugs found on eo

It looks like my game POLICE PATROL isn't accepting keyinput anymore.

I have loaded multiple versions of the game, even version in a downloadlink that I have marked OK for distribution.
games.zip
(229.15 KiB) Downloaded 6 times
by dr beep
Thu Apr 18, 2019 10:42 pm
Forum: GAMES
Topic: New ZX81 Games
Replies: 136
Views: 83783

New ZX81 Games : GAME 59 in 1K hires

Name of Software: Chernobyl Bomber Author: Johan "Dr Beep" Koelman Release Date: 18/04/2019 Requirements (eg. 1K, 16K, AY Card, Hi-Res Scheme): 1K hires Description: Land your plane safely in Chernobyl cbomber.png Download link (if available for download): cb.p Commercial / Public Domain / Freeware ...
by dr beep
Tue Apr 02, 2019 7:30 pm
Forum: GAMES
Topic: New ZX81 Games
Replies: 136
Views: 83783

New ZX81 Games : GAME 58 in 1K hires

Name of Software: Wiwo Dido's mapped maze Author: Johan "Dr Beep" Koelman Release Date: 02/04/2019 Requirements (eg. 1K, 16K, AY Card, Hi-Res Scheme): 1K hires Description: Find your way out of the maze. WDMap.png Download link (if available for download): mapmaze.p Commercial / Public Domain / Free...
by dr beep
Sun Mar 24, 2019 11:58 am
Forum: ZX BASIC
Topic: What is so bad about using Floating Point math in a BASIC program
Replies: 3
Views: 956

Re: What is so bad about using Floating Point math in a BASIC program

It is slow, even in the display of a number. I recently coded USCII and ran the same program in pure ZX81 BASIC and with USCII which only does a different way of displaying a number. It only accepts a positive rounded number to be printed. Even with this change only the ZX81 BASIC is twice as fast a...