All posts for the month January, 2012

SYM-1 Computer (Synertek)

Synertek’s SYM-1 microcomputer, programmable from the hex keypad, with 6-digit LED readout.

The SYM-1 appears to be dead. It does not give its customary “beep” when powered up, the display remains blank, and there is no response to any key presses. Further, some of the chips appear to have rotted. I have removed it from Microtron in preparation for the robot’s long-awaited system upgrade. Also gone are the original A/D converter circuitry, the bumper-hit detection circuitry (both circa 1982), and a slew of old wires.

My current thought regarding most of the legacy circuitry is to keep boards if they work; remove or replace them only when needed.

Microtron knows which direction it is turning because of a potentiometer that reports the current position of the turning wheel back to the central processor. The original potentiometer that was installed in 1981 had apparently disintegrated at some point while the robot was in storage.

As one of the steps needed to get Microtron working again, I replaced the pot’ and pressure-mounted dowel today.

the new and the old

Pictured above on the right is what is left of the old potentiometer, and on the left is the new replacement pot’ and dowel.

Mounting point
Directionless —^

New potentiometer installed

I ordered the Phidget Interface Kit 8/8/8 today. I read the description and it appears that the rat’s nest of sensor cables, miscellaneous wires, and assorted home-brewed circuit boards that are currently on board my Microton Robot can all be replaced by one off-the-shelf, miniature-sized component board. The field of robotics has apparently come a long way since the early ’80s.

The Phidget 8/8/8 boasts 8 analog inputs, 8 digital inputs, and 8 digital outputs. This will cover all of Microtron’s currently designed functionality, with plenty of room for expansion down the road. Phidget also supplies the library as GPL’d source code, which I hope means that I’ll be able to develop on a GNU/Linux system.

Another plus: I’ll be able to access the device via a single USB port. After programming Microtron in 6502 machine code (w/ 4K of RAM), I’m really looking forward to doing some higher-level, language based robot programming instead.

The phidget libraries are written in C and I plan to write the first stages of Microtron’s new code in C as well. Some of my AI theories are object-based, so I may play around with Objective-C once Microtron’s basic functionality is working.