The Motorola 68000 Educational Computer Board (MEX68KECB) was a development board for the

Motorola 68000 The Motorola 68000 (sometimes shortened to Motorola 68k or m68k and usually pronounced "sixty-eight-thousand") is a 16/32-bit complex instruction set computer (CISC) microprocessor, introduced in 1979 by Motorola Semiconductor Products Sector ...

microprocessor, introduced by

Motorola Motorola, Inc. () was an American Multinational corporation, multinational telecommunications company based in Schaumburg, Illinois, United States. After having lost $4.3 billion from 2007 to 2009, the company split into two independent p ...

in 1981. It featured the 68K CPU, memory, I/O devices and built-in educational and training software.

Hardware

* CPU: 4-MHz Motorola 68000 * RAM: 32KB * ROM: 16KB * 9600 baud serial port for

dumb terminal A computer terminal is an electronic or electromechanical hardware device that can be used for entering data into, and transcribing data from, a computer or a computing system. The teletype was an example of an early-day hard-copy terminal and ...

connection * 9600 baud serial port for host computer connection * Parallel port for communication and printer connection * Audio output for tape storage * 24-bit

programmable interval timer In computing and in embedded systems, a programmable interval timer (PIT) is a counter that generates an output signal when it reaches a programmed count. The output signal may trigger an interrupt. Common features PITs may be one-shot or periodic ...

* Wire-wrap area for custom circuitry * Required power voltages: -12V, +5V and +12V

Software

The board has built-in 16K ROM memory containing assembly/disassembly/stepping/monitoring software called TUTOR. The software was operated using

command-line interface A command-line interpreter or command-line processor uses a command-line interface (CLI) to receive commands from a user in the form of lines of text. This provides a means of setting parameters for the environment, invoking executables and pro ...

over a serial link, and provided many commands useful in machine code debugging. Memory contents (including programs) could be dumped via a serial link to a file on the host computer. The file was transferred in Motorola's S-Record format. Similarly, files from host could be uploaded to the board's arbitrary user memory area.

Price

The price of the Motorola ECB at launch was which was relatively inexpensive for a computer with an advanced for that time 16/32-bit CPU.

Use

According to the manual, for basic use only a dumb terminal and power source are required. However, it seems that in colleges the board was predominantly used in connection with a time-sharing host computer to teach assembly language programming and other computer science subjects.

References

{{Reflist MC68000 Educational Computer Board User's Manual

External links

* MC68000 Educational Computer Board User's Manua

Early microcomputers Microcomputers Single-board computers