Posted By
MCes
on 2019-11-04
10:08:08
 |  Re: Photo of an unknown 64kB memory expansion
A cart is not sufficient to define its work: on the instruction manual you can find which traces has to be cutted....
example:have a look at the last pic.... you have to cut the pins9 of your ram chips...
64K-RAM Speichererweiterung
I'm suspecting that the only cart that could work (improperly) are the cart that has a transistor on it because the /CAS signal could be overloaded to Vcc (so it remain in H state = not RAM access) but this overcurrent can be sensed by B-E junction of a PNP transistors that can used to sense the /CAS signal for driving the cartridge RAM without bus conflict....
This method can work, but the TED /CAS line will be overloaded and it couldn't be a great idea for the TED health...
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