> Now to the point with an external mapper, all the higher bits are read as one :
>
> e.g.
>
> Internal 512 Kbyte mapper
> External 2048 Kbyte mapper
>
> out &hfe,1
> in &hfe -> &b11100001
>
> This is with and without the external mapper!
> I could be wrong, but I think with a 256 kbyte turbo-R ST even bit 4 will be high.
> By adding a pull-up to a certain pin, the engine can be configured at power-up.
The point here is:Does this external mapper support read-back? As far as I understand
many
of the extensions
don't support reading of their mappers (for example AddRam, if the circuit diagram of
it
that I found on the Net is correct)
> The engine wins the battle of the higher datalines because in series with the
>datalines
> from the processor(s) to the cartridge connectors there are resistors.
> (I think they are 100 ohm)
Probably you are right here. (however 100 ohms seems a slightly bigger value than
usual 22
or 33 ohms)
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