The Sinclair QL Forum

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I decided to remove this post as I can not re-check the scope setting. I currently do not have access to the scope and the QL board.

Stephan

Hi Leon,

great next step! Thanks for sharing here. It is really fun to play around with your development.
Stephan

Hi all, during the build of a second QL-VGA converter I found a strange issue. After copying the code to the virtual USB drive the board worked as expected. But after de-powering and re-powering it seems the code has been vanished or the RP2040 failed to start. In fact another forum member reported ...

You may ask whether this guy can read out the PAL content. Probably not 100% exactly the same but it may help to understand.

https://www.nightfallcrew.com/?s=SPEM

Stephan

Hi Chris,

to find the short you may consider to apply current 100mA to 200mA with an adjustable power supply. Then just feel which chip gets hot.

Stephan

I met Carlo around 1992 / 1993 at a QL meeting in the Netherlands, and I recall that MDV support was not possible: (2) MICRODRIVE support The MicroDrive subroutines and matching Hook codes of the ZX Interface 1 Shadow ROM are fully emulated. Nonetheless, it is not (yet) possible to read ZX Spectrum ...

There are also emulators that (nearly) completely emulate the ZX Interface 1 with Microdrive and serial port emulation. There are really ZX Spectrum emulators for the QL that emulating the ZX Microdrive? In terms that you can put in a ZX Cartridge into the QL Microdrive and load from it? Can you po...

Problem solved. Thanks to everybody who contributed

Stephan

Hi Derek, thanks for your answer. This is basically what I did but using the tool here: https://www.nightfallcrew.com/minervaram/index.php It tells me that all Ram chips from 1 to 8 are faulty. Which is somehow unlikely to me and let me think to check for other possible causes first before changing ...