A new page has been created, see links on the right (or... somewhere, on your smartphone): ZX81 alive Web Directory - a collection of active Sinclair ZX81 related websites.
Currently there are 21 links, but more to come, and if you like to add your website just leave a comment, or post it in facebook group "Keeping the Sinclair ZX80 and ZX81 Alive".
(NOTE: The similarity of facebook group name "Keeping the... Alive" and "ZX81 alive" is pure coincidence. But it is quite fitting.)
A new video of parallax scrolling, with a significant speed increase.
With an upgraded ZEsarUX emulator, and a little bit of newly gained know-how about ZX81 BASIC compilers, a machine code version of the "PARALLAX" demo was created.
"MCODER2" is an easily available compiler, and basically just two USR calls (via LET) are required to do the compilation. There are a few limitations to what BASIC code MCODER2 can handle, but interestingly it looks as if in this case none applied. (See MCODER2 documentation, and source code in the video.)
Anyway - the increase in speed is quite nice. :-)
Yesss! The first ZX81 alive video has been uploaded to YouTube.
It shows a little experiment in creating some sort of parallax-scrolling 3D view, written in BASIC. Source code is shown in the video. (Well, it's not too spectacular. ;-) )
Maybe an inspiration for your own coding efforts?
Enjoy!
Here's a very good article extensively explaining the ZX81's video display system.
Written by wilf rigter in 1996, this tutorial from 8bit-museum's collection of Sinclair scans gives excellent information about how all things video work in a ZX81.
https://8bit-museum.de/heimcomputer-2/sinclair/sinclair-scans/scans-zx81-video-display-system/
Yes, the ZX81 can do it, too.
The ZX81's audio capabilities are seriously limited, meaning it simply lacks any sound chip or DAC or anything, thus everyhing. But it does write and read data to audio cassette tape recorders, sooo...
...precisely. The MIC and EAR connectors on the ZX81 are in no way meant to deliver what a sane person would call sound, but of course it still is an audio signal, only in a very crude way. ZX81's BASIC only provides the LOAD and SAVE commands to access the tape ports, so some machine code is required to get in control. The idea is not really new, but it looks as if "Sound Digitizer" by NICKMANN Studio is an exceptionally nice implementation. Also the accompanying article (see link below) gives a lot of interesting and helpful information about the fundamentals of digitized sound.
Here you can see and hear it in action on NICKMANN Studio's YouTube channel (2023-03-16):
Check out NICKMANN Studio's website for more information, and don't forget to send some coffee:
https://www.buymeacoffee.com/nickmannstudio/zx81-sound-digitizer-english
A nice project by "X-periment" provides a framework to do fast 3D graphics in "plot" mode, and shows some well known 3D objects.
"A fast 3D low-res graphics library for the ZX81" (Nov 5, 2022)
If you want to know more, check out its github pages:
https://github.com/X-periment/ZX81-graphics-library
...and X-periment's YouTube channel:
"SINCLAIR ZX81 Screen editor" is a new tool for creating ZX81 character set graphics on Windows computers.
Quite similar to zx81paint for the Amiga, but probably more advanced, "SINCLAIR ZX81 Screen editor" allows Windows users to create graphics made from the ZX81's character set. A typical application would be to design game screens, then export the results as a sequence of characters for use in the game. But the editor can do more: it can also import 64x48 pixel BMP pictures to PLOT-pixels, and save hi-res JPEG pictures of your screen design.
Go to "SINCLAIR ZX81 Screen editor"'s website for more information:
