Q-Bus PDP-11 Memory
When I reanimated my Plessey Peripherals System I had two 256kbytes Memory cards. Later I acquired a second backplane and started with an orphan M8186 board which later turned into my primary Q-Bus system. But at one time one of the Memory cards broke and I was left with only one memory card. Since I already built a Q-Bus card for the PDP-11 which worked pretty well I thought this is the perfect moment to build my own memory card for PDP-11 Q-Bus systems.
A PDP-11 is more fun to use, when you have more memory, especially when your system supports 22-bit addressing. This article is about the first memory card I have built for Q-Bus systems. This is a very simple Memory Card which uses 1M x 16 bit SRAM. It supports one or two SRAM for a total of either 2Mbyte or 4Mbyte of RAM.