Jim Brain wrote: > M H Stein wrote: >> Any chance you could also put the two rows of pins for a 6540 >> replacement >> on there while you're at it, to use either a 2732 or 1/2 of a 2764? Would this work: http://www.jbrain.com/vicug/gallery/ROM-el/6540_ROM_el_PCB I made some assumptions: CS3,4,5 are active low CS1,2 are active high CLK is active high I'd appreciate knowing if those are valid or invalid assumptions. * As the schematic shows, the design uses a 74'138 to decode all of the CS lines and CLK into a single CS line for a 2764-27512 * I can add a jumper to allow 24 pin EPROM operation (hook pin 26 to pin 28) * Extra address lines are pulled up to 5V and available on pads on top of adapter (to allow switchable ROMs) * logic and resistors are hidden inside 28 pin header. Let me know if there is any interest. Jim Message was sent through the cbm-hackers mailing listReceived on 2009-05-06 05:17:26
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