Changes

Maplin ROM Box

221 bytes added, 12:12, 29 June 2011
/* Description */
* 6x8bit I/O port (using two [[8255 PPI chip]]s)
* Additional power-supply module (PSU)
 
== Technical ==
 
ROM is selected using an I/O port decoded with A15=1, A13=0. The ROM number is decoded using D3-D0 only, meaning a maximum of 7 ROMs can be used.
In addition more then one value can select the same ROM.
== Pictures ==
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