ACU Romboard (DIY): Difference between revisions
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==Technical== | |||
ROM Selection is made using a port decoded with A13=0, A14=1. D3 must be 0, D2..D0 select the ROM, allowing up to 8 ROMs to be selected, but the PCB only has 6 EPROM sockets. Sockets for ROM 0 and ROM 7 aren't fitted. | |||
More than one value can select the same ROM (e.g. &11 will also select &1). | |||
[[Category:Peripherals]] [[Category:DIY]] | |||
Latest revision as of 08:53, 30 June 2011
A DIY project to make a romboard
Designed by Phil Craven, released in Amstrad Computer User (December 1988, pages 35,37,38).
Technical
ROM Selection is made using a port decoded with A13=0, A14=1. D3 must be 0, D2..D0 select the ROM, allowing up to 8 ROMs to be selected, but the PCB only has 6 EPROM sockets. Sockets for ROM 0 and ROM 7 aren't fitted. More than one value can select the same ROM (e.g. &11 will also select &1).