If you have a RAM cartridge with 32K of RAM then you can use the select signals to create a 'pseudo A14' address line and feed that to the RAM chip. This will only work if the cartridge has the extra logic and 32K of RAM (like the one I made), and has to be plugged in to the far left hand slot as that is the only slot with all 8 select lines.
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https://www.youtube.com/watch?v=sqzKWH5p728
Yes, the minute hand fell off.
I popped it back on.
More here :
https://trochilidae.blogspot.com/2018/10/breitling-aerospace-ive-had-my.html
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https://www.youtube.com/watch?v=MwUlwVFasw0
A first attempt at a Psion Organiser 2 USB adapter that uses similar circuitry to the comms link. A few problems are encountered.
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https://www.youtube.com/watch?v=6xNyrwsTV7U
This is the second part of the Sinclair Memory calculator teardown. This has the display and ICs under the microscopes.
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https://www.youtube.com/watch?v=nnP6pLSq5eQ
The logic from the flash datapack has been pulled out and put on a breadboard for debug.
Does it work? Well, no.
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https://www.youtube.com/watch?v=0Affvz9h7U0