Sinclair ZX80 / ZX81 / Z88 Forums

The resulting programs after my crappy fix: could anybody see if it fixes the problem ? I could have introduced the problem trying to reduce the code size (e.g. heavily relying on ROM calls) because changing the way to test the BREAK condition is apparently enough to solve the problem. The code size...

Hello, I remember that behaviour, I never understood it was appearing because of the ZXpand interface! I was finally able to reproduce the problem, I'm inserting a simple fix which solves on EO. The current driver code is here, it is quite different from the original one because it includes video ef...

A brand new video showing a F.IZ. disk drive controller in the ZX Spectrum version

https://youtu.be/7Js6sFHqqX4

The TRD format is a pure sequential, sorted dump of the disk sectors. The formatting is guessed by the emulator depending on the file size.
I suggest to try with SAMDISK, it is usually able to convert to other disk dump formats by adding the needed extra detail.

There's surely space for improvements, like a colour version of the game or trying to exclude the initial banner and compress the maths by using the ROM. By the way here's a first, mostly untested version of the DALLAS game for the Lambda with 32K RAM, in the three ROM flavors (V1, V2, and CAC3/NF30...

This is an odd one. While disassembling the CAC-3 and NF300 ROMs I ran into a strange behaviour of th STK-FETCH routine. First of all, differently than on the ZX81, it was positioned at $20 permitting it to be invoked by RST rather than CALL and save a couple of bytes every time. Ok, that happens al...

I'm halfway in the process of tracking the ROM differences on the CAC-3 and NF300 models. They're VERY similar, but apparently the NF300 is sensitive to the machine code included in a REM line, or perhaps the LOADed block, even if working, should be formatted slightly differently. So, supposing we h...

I'm close to the end of a first pass on the z88dk libraries. There's still a couple of very small differences between the lambda ROM (new type) and the cac3. It's a very small difference regarding the number to string conversion, I'll looks closer to the zx Spectrum, it lacks the string termination ...

When the TV brightness passed a threshold, the raster picture was generating a buzzing noise which was received by a software loop.
The software was changing the brightness of video portions to find the right spot you were pointing at
A scanner requires an audio oscillator I think?

I may be wrong, but it looks a similar concept to the light pen for the Spectrum, it was for the main part a software trick