dennisg@felix.UUCP (Dennis Griesser) (07/09/88)
The May/June '88 issue of "Circuit Cellar Ink" carried an article called "Power-Line-Based Computer Control" which described the internals of X-10's PL513 module. This is a no-frills controller that feeds sync pulses to the computer and uses a gate signal from the computer to impose the X-10 carrier on the line. If you are seriously considering building one of these from scratch, instead of buying the assembled unit, you might be better advised to read: Computer Digest - May 1986 - "Remote Power Controller For Your C-64" This is a "sync-and-gate" interface that works like the commercial PL513 unit. The advantage is that it much simpler to build: 5 transistors, a 556, and some R&C. It, too, features optical isolation on both signals. Only one program is provided. It is a C-64 BASIC program that pokes a machine-code subroutine into RAM and calls it. Luckily, the software in "Circuit Cellar Ink" (May/June '88) should work with this unit.