t0nyt wrote: ↑Sun May 05, 2024 7:52 am
This is certainly something I'd be keen to do when circumstances allow (I'm a 24/7 carer with little time or space to do something like this), but if you can let me know exactly what I should get I'll get it in ready so I can give it a go as circumstances allow.
Hi Tony,
The logic analyzer I have is by HiLetGo, but I see there are others that look exactly the same and cost even less.
I would recommend PulseView (free) for the software on the Mac/PC side, as it saves the traces in a format that I am able to read.
The main issue is how to attach the wires from the analyzer to the microdrive connector. Here are some ideas, but maybe someone better versed in electronics than me can offer additional ones:
- Connect a MDV cable if you have it, and use probe hooks between the analyzer and the cable
- Buy a connector for the MDV PCB connector and attach the analyzer to it with the cables that come with the analyzer
- Use hooks to connect to the lines inside the QL (e.g. microdrive ULA pins)
The process to collect the trace should be pretty easy:
- re-felt the MDVs and connect the logic analyzer to the two data lines and GND (on the side microdrive connector, or inside the QL)
- boot the QL (standard Sinclair or Minerva ROM is fine), insert microdrive and turn the motor on (I can send you code for that if you don't have it already)
- on the Mac or PC, run PulseView and start recording at the max frequency (24 MHz), say for 1G samples, that should be about 40 seconds and allow recording the entire tape at least five times
- email me the output for decoding and creating a microdrive image (in non-standard format... from memory, I think they used 100 sectors of 1 KB each).
Parts needed:
- logic analyzer
- either a PCB connector, or hooks for the logic analyzer with optional MDV cable
Later I can send you pictures of the various components I mentioned.
Thanks for the software preservation work you are doing!
Daniele