Sinclair ZX80 / ZX81 / Z88 Forums

I have never tried to load any WAV files, only TAPs from JAA websites. If you have TZXduino I could share a few files that works and you try with them.

Bear in mind that Jupiter ACE TZX files should be converted to ZX Spectrum timings if you would like to use a bulk standard TZXduino firmware.

Pin 13 of Z14 is directly connected to the data line D5 and you can see all data flowing there. Take pin 13 of Z14 out of the socket and then see what you have there during the LOAD execution. If you would like to separate LOAD signal only, the oscilloscope should be triggered by the 0xFE read pulses.

Do you load TZX files or WAV? Are you sure that your TZX player can generate waveform with correct Jupiter ACE timings and it could be understood by Jupiter ACE? Jupiter ACE timings are different to ZX Spectrum ones. 1kHz sounds right for "0" pulses. Pilot's frequency is approx 800Hz, a logical "1" ...

Hi and congratulation with your build. Regarding the loading issue, try to replace C3 (47nF) to 470nF or more and check.

Looks good!

BTW You might find my Twister (JACE -> ZX81) useful and more details are there: http://www.jupiter-ace.co.uk/hardware_twisterboard.html

HI Andy,

You can find some information about the CF card mass storage there: http://www.jupiter-ace.co.uk/hardware_ACF.html

I am not sure if the modified ROM has been ever published.

Congratulations.

From photos I can see this is not the board which I recreated. It seems to be a Russian PCB.

Good work with keyboard, and keep my fingers crossed for it.

Hi, Interesting findings. Anyway, in Europe PAL-B/G is used and its colour subcarrier frequency is 4.43361875 MHz. In case of PAL-N, the colour subcarrier frequency is 3.58205625 MHz and a channel bandwidth of 6MHz. So, PAL-N spec is very close to the NTSC spec, and it might be a reason why Sinclair...

Good job and thanks for sharing

They look great and well done.

Thanks for sharing.