Sideways RAM
In addition to ROM, banks of RAM could be added to the computer via the Sideways address space. The BBC Micro is hardwired to deny writing to the Sideways area, so a write signal needs to be collected from somewhere. The methods vary, but the two most common methods are: removing chips from the board and placing them into an expansion board that occupies the chips' original sockets, and: fitting a RAM module in a ROM socket with a flying lead connected to a write signal elsewhere on the motherboard. The BBC Master was re-engineered to support Sideways RAM, and could be configured with motherboard links as to which banks were ROM and which were RAM. RAM could also be plugged into the external cartridge ports.
Read more about this topic: Sideways Address Space
Famous quotes containing the word ram:
“At one time or another, almost every politician needs an honest man so badly that, like a ravenous wolf, he breaks into a sheep-fold: not to devour the ram he has stolen, however, but rather to conceal himself behind its wooly back.”
—Friedrich Nietzsche (1844–1900)