The high speed option adds a double precision mode allowing the A and B registers to act together as a 31 bit accumulator and allowing double precision addition, subtraction, load and store. A new flag is added recording whether the machine is in double precision mode. Instruction set For the details of the standard instructions see table of standard instructions . In addition to the standard instructions, defined by Honeywell, there are a series of other useful instructions. The series 16 machines have, for the most part, a regular and orthogonal instruction set.
Most instructions are memory referencing instructions.
DIV Divide Two of the sixteen opcodes are not used for memory referencing instructions. Instead they indicate other classes of instructions, in these two the two bit addressing mode field is reused to distinguish four cases. Memory is supplied, at least in the case of the H316 model, in multiples of 4K words. Each sector is 512 words. The base sector is selected when the sector bit is zero, and the current sector when the sector bit is one.