Sinclair ZX80 / ZX81 / Z88 Forums

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

I'm in touch to @olofsen, he shared his work and I'm merging as much as possible in the current z88dk tree. I'm working on the emulators so I'm not totally sure that the updated code is still generating valid raster pictures on the real TV sets, 50hz and 60hz, but the rest of the library is surely i...

I think it is worth to mention also the Seikosha GP50S. It was another one fully compatible with the zx printer

I also updated the ZX81 specific version of DSTAR to get a valid version for the ZX80 with "NEW ROM" (aka ZX81 in FAST mode). It looks a bit flickery on EO, the results look much better in 50hz mode, but I can't predict how it will be on a real TV. Probably the "intelligent" color TV and LED TV chip...

It is a bit of fun having the code repeatedly checking the hardware status! You might even add a switch on the 50/60hz diode and the raster frequency would change at runtime :) Thankyou for the information, at the end I chose a different approach and totally replaced the fgetc() code to reduce flick...

I finally succeded in getting the display visible in FAST mode also on the ZX81 and on the LAMBDA ROMs (untested).
This program should run correctly on a ZX80 with ZX81 ROM as well as on a ZX81.

I'm wondering what's the right way to check if we're in FAST mode.
I'm concerned in trusting the system variables because the ZX81 ROM can be running as a retrofit in a ZX80, which obviously is never in FAST mode.
I haven't fully understood how the SLOW/FAST subroutine works in rom

I've been recently working on the less common versions of the LAMBDA 8300 ROMs, and hopefully I made everything more flexible by adding two new subtypes ("mono" for the v1 ROM and "cac3" for the CAC-3 and the NF300). While woring on it I noticed that I had never ported some of the ZX81 functions, su...