Hi Jay,

For some reason my brain had decided that PSEN', RD' and WR' needed to be rerouted (so including a remapping signal I needed four inputs + an inverted A15 on one of the enables).. whilst I was writing earlier, it occured to me I only needed to re-route WR' (+A15).. I could use a '139, but I would have to invert A15 (as in the case of using the '154) which I don't need to do with the '138.. also, both the '138 and '139 have the same pin-count.. so I might as well use the '138.

Thank-you for suitably stimulating my mind!!! ;-)

Matt.