New Micros Inc. (NMI) NMIS-0021 F68HC11 based CPU board

2x4"s[tm] single board computer with TTL serial SCI, SPI 64K address, 2 memory sockets, 8K SRAM

The NMIS-0021 is the F68HC11-based CPU board for the 2x4"s[tm] board series.

FEATURES:

• F68HC11[tm] CPU
• Max-FORTH[tm] built-in programming language
• 231 predefined words in the language
• 3 parallel ports
• 1 Asynchronous Serial Channel
• 1 Synchronous Serial Channel
• 8-channel, 8-bit A/D
• 8-bit counter
• 16-bit timer
• 3 input captures
• 5 output compares
• 1/2K EEPROM
• 1/4K RAM
• 64K address space
• Two 28-pin JEDEC memory sockets
• Flexible address decoding, socket assignments
• Capacitor & Battery backup circuits for memory
• 34-pin JEDSTACK[tm] Vertical Stacking Connector (VSC)

The NMIS-0021 is a complete system, ready to run dedicated applications. Only the addition of the user program is required, in its internal EEPROM, or its battery backed RAM, or in a user-supplied ROM/EPROM/EEPROM.

The 2x4"s[tm] series of computer boards were designed with low power operation and minimal size in mind. The 2x4"s[tm] are the perfect building blocks when designing systems or stand alone single board computers. They were named 2x4"s[tm] for their size, 2 x 4 inches, and to emphasize their similarity in concept to the popular mechanical building block. The system is compatible with the larger New Micros NMIX and NMIT series computers. The VSC has the same pinout on all these versions. The sockets accepting JEDEC memory devices have the same pinouts on both systems. Refer to the figure at the left.

To download code to the NMIS-0021's processor, or interactively develop code, additional circuitry is needed to "talk" to the systems with RS-232. A level shifter must be used with terminals, or personal computers, with RS-232 ports to convert the TTL serial in and serial out to RS-232 levels. This can easily be accomplished with an NMII-0232 board. Refer to the figure above.