Sunday, April 4, 2010

My Skunk Works Project

What is a skunk works? A definition from Wikipedia: The designation "skunk works", or "skunkworks", is widely used in business, engineering, and technical fields to describe a group within an organization given a high degree of autonomy and unhampered by bureaucracy, tasked with working on advanced or secret projects.

In order to prototype the multiuser shop floor control system, I needed a real video terminal. The idea would be to take a computer and install one or more multiport RS-232 cards and connect terminals to them from all over the building.

The following work was done more or less under the radar. I wasn't trying to get away with anything, but I hoped to surprise Bob with the results I hoped to achieve. I managed to requisition an old Lear Sieglar ADM-3A terminal on the cheap. This was one of those pastel blue terminals with a "space age bubble" look to it. Needham High School had a few of these connected up to their PDP-11.

In order to make this work with Smalltalk/V I needed a tiny machine code routine so I could make calls to the serial port. I was lucky to find someone on a bulletin board who was kind enough to write this for me. I was even luckier that it worked! The machine code file was only 14 bytes long!

It didn't take me very long at all to create a master monitor, a login routine, a simple command parser, a simple job object, departments that could hold jobs, and the ability to move the work from one department to another and list the contents of each department.

What was absolutely most amazing about what Smalltalk/V made possible is that the system was extensible and debuggable... as it ran! If there was a runtime error while executing some command from the terminal, a debugger opened on the computer screen. I could then fix the bug right there, and the terminal could be restarted without bringing the system down for a recompile.

This was very promising to say the least.

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