Sinclair ZX80 / ZX81 / Z88 Forums

I found a way to code a 1K lowres centipede. Now in the new games section.

Name of Software: KILOPEDE Author: Johan "Dr Beep" Koelman Release Date: 02/04/2024 Requirements (eg. 1K, 16K, AY Card, Hi-Res Scheme): 1K lowres Commercial / Public Domain / Free ware / Other - please specify? Freeware Description: A 1K version of CENTIPEDE Kilopede.png EDIT: BUGFIX FOR SHOOTING ED...

Name of Software: BUGGERCODE Author: Johan "Dr Beep" Koelman Release Date: 30/03/2024 Requirements (eg. 1K, 16K, AY Card, Hi-Res Scheme): 1K lowres Commercial / Public Domain / Free ware / Other - please specify? Freeware Description: A 1K version of MICROMOUSE GOES DEBUGGING buggercode.png Download...

Name of Software: Solitaire Author: Johan "Dr Beep" Koelman Release Date: 23/03/2024 Requirements (eg. 1K, 16K, AY Card, Hi-Res Scheme): 1K lowres with CHROMA COLOUR AND GRAPHICS possible Commercial / Public Domain / Free ware / Other - please specify? Freeware Description: The classic cardgame in 1...

Great read, now I need to take a look at the code.

Why would you edit machinecode? You should always place new versions of your code over the line, but better code outside the ZX81 and built a .P from that. In this way you can use much more of the RAM, like printerbuffer, sysvar and no loss of bytes for line nimbers and lengt or start of machinecode.

Name of Software: HRLBS Author: Johan "Dr Beep" Koelman Release Date: 11/03/2024 Requirements (eg. 1K, 16K, AY Card, Hi-Res Scheme): 1K lowres Commercial / Public Domain / Free ware / Other - please specify? Freeware Description: HRLBS.png Downloadlink: HRLBS.p Source: HRLBS.asm Video https://www.yo...

So I've got two partially failed ULAs ... or potentially to be generous, two ULA's that can't perform to the standard where WRX hires graphics will work, even if I was using the original 1k RAM. I think you have bunked why "some" ZX81s did not work with my hiresgames. We wanted to release a tape wi...

I made a simple testprogram out of a game.

After NEWLINE you will see 16 hires lines (well more, but also lines with zero)

First line 1 and 1
spaceline
Second 2 and 2
spaceline
Third 4 and 4
etc....

So you can see which bit are set by your computer.

Closer look at the picture

First thought:
The text is ok, but some bits are
somehow set.

The best thing you could have is a simple
display with just 1 (adjustable) value and see how that display appears.