8031 Student PCB

8031 timeline

The layout simply had 1994 outside the board edges. The board was available for unlimited educational use. The first class was the 1994, second semester Digital Systems group at Port Elizabeth Technikon.

A better way of teaching

Encouraged by the speed that students grasped microcontrollers when programming them rather than glossing over a few pages in a general text book, a board was laid out that students could buy at cost. Prior to this, projects involved each student laying out a board and grappling with lead times at PCB manufacturers. Low volume runs were generally a problem, but the vendors had a soft spot for students. Grouping everyone’s layout for sending would still take at least a week turnaround (Port Elizabeth to Cape Town for files and return delivery of boards, two days manufacture, etc.), plus a budget under $20 per student. Photo plotting alone would cost more. There were generally thirty students per class, which made it worthwhile for runs of several boards. The keypad, setup switches and LEDs could be placed on either side of the board.

8031/51 PCB board back

A board where the student chose to place the LEDs, keypad and setup switches on the solder side of the board


The photos of these boards were resurrected many years later to piece together this website. Some were not so clear. At the time, most of my photographs were on film. Early low resolution digital prints looked awful. The boards used 8031 or 8051 devices with external memory, or the EPROM version—8751. The processor ran at 11 MHz with 12 clock cycles per instruction, giving almost 1 million instructions a second; more than enough for a small HMI.

This was a much neglected part of all designs; packaging a small panel would probably have made a successful product. As it was, a fair amount of processing on a 680x0 system in previous designs and a later Atmel 8515 effort took much longer than a day to complete.

The first batch had two missing connections—sloppy checking I guess. Warwick Smith was the first student to pick up any layout problems. (More about Warwick’s other achievements are sprinkled around this website).

8031 PCB board top

Component side with LEDs on the top side.