EXPAnDDR Board

A stripped-down, low-cost interface board that delivers three of the ADAM's most-wanted internal upgrades on one card: a socket for a BOOT PROM (a chip whose start-up code runs the instant the ADAM powers on — useful for booting from a hard drive or loading diagnostics), a Centronics parallel port for standard PC-style printers, and the memory-expander "addressor" signal.

That last item matters because the ADAM cannot reach memory cards larger than 64K on its own; a board like this must supply the extra "addressor" signal that lets big 256K–1MB expanders bank-switch their memory into view. The EXPAnDDR is aimed at owners who want to experiment with boot PROMs, diagnose a faulty machine, drive a parallel printer, or simply add an inexpensive addressor. Installs in expansion slot #2.