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 of replacing the tube by the transistor for TV's, we can see that there are almost no trade-offs to be made in using microcomputers. Designs are at the same time lower in cost, more flexible, more reliable, use less power and fewer components and are simpler to manufacture and maintain.

Now that the game designer is convinced that a microcomputer will improve a new design in almost every category, one is still faced with the problem of selecting the best device to meet the design goals among the wide variety of devices available. To determine the most important characteristics is not always easy, but generally involves a weighting of the following: Cost

Availability (second source?)

Input/Output Capability

Memory Size

Instruction set

Speed

Power

Interrupts

Reliability

Supplier Reputation

Temperature range

The MOSTEK F8 microcomputer family has unique architecture and performance features that make it ideally suited to meeting the most important requirement for games–namely good performance at low cost in volume. Many of these important characteristics are summarized by Fig. 3.

The current family of MOSTEK F8 parts consist of the following:

MK3850–CPU (Central Processing Unit) with 16 bits of I/O, 64 byte scratchpad, internal reset and oscillator circuitry.

MK3851–PSU (Program Storage Unit) with 16 bits of I/O, IK ROM, programmable timer, and external interrupt.

MK3853–SMI (Static Memory Interface) interfaces the CPU to up to 65K of static memory, ROM, RAM or PROM. Also has programmable timer. Used to expand memory.

MK3852–DMI (Dynamic Memory Interface) interfaces the CPU with up to 65K of static dynamic memory. Contains dynamic memory refresh circuitry and automatically controls MK3854 DMA chip. Used to expand memory.

MK3854–DMA (Direct Memory Interface) permits transparent DMA up to 500K bytes/sec. Used for high speed data transfers.