Ferranti F100-L

F100-L is a 16-bit microprocessor, designed by British company Ferranti Limited for military applications. Introduced in 1976, the processor operated at frequencies from DC and up to 8 MHz, and could directly address 32K words of memory, or 64 KB. The CPU instruction set was comprised of 28 basic instructions, and supported direct, pointer indirect, immediate and indirect immediate addressing modes. Depending on the instruction, its execution time could be as low as 1 microsecond, or as high as 6 microseconds, and the average instruction execution time was reported to be in the 3 - 4 microsecond range. The F100-L system could be "expanded" to handle multiply and divide by adding external chip, such as F101-L.