A quick initial Web page about the Scitronics S-100 X-10 controllers. Thanks to John Tucker who sent me a board and its manual in Sept 2026. - Herb
Here's the PDF of the manual for this version of the board. It now includes photos of the board I received with that manual. The chips on the board date to 1979. There's no schematic, but there is an operational description of the board. The documentation does not use the phrase "X-10". I wonder if there was some kind of license needed to claim X-10 compatiblity and use the phrase?
I also have two more S-100 cards of this same type. Please note, my designation "#1" and "#2" below, are
arbitrary and not terminology used by Scitronics.
Also I have this Scitronics board, also an X-10 board, but a very different design. Note the prominant silkscreen title on the board, "Scitronics Inc Remote Controller". The chips on the board date up to 1981. Without docs, I have sketched out the IC identifications for the board.
There's a GI brand (General Instruments) IC on this, "PICO 542C CCA" which I'm told may be an X-10 based controller. GI produced many telecom (filters, TouchTone) decoder/encoder ICs in the period. X-10 the company produced a 541C controller at one time which was functionally reproduced later.
The AC circuit side of this board is different from the #2 board. Here's another view there's
IF type transformers (IFT) "cans" there, marked "Toko RCL" (no other marks). I have no docs or schematics (but see the "tech note" in the next section). . NEil Cherry tells
me in Sept 2026: "From the simple view of this board, and the docs you provided, I'd say this is a X10 Transmitter board. "
I'd appreciate any information someone has on this board. Please note, my designation "#1" above and "#2" here, are arbitrary and not terminology used by Scitronics.
The "Toko RCL" IF transformer (cans) devices measure 10.5mm square and some similar height tall. They are Toko brand IF Transformers (IFTs) apparently, and may be tuned for 120kHz X-10 operating frequencies. One of them has five terminals on the PC board, two terminals one side and three on the other side. DC resistance measurements shows the two-terminal side is continuous and very low resistance; the three terminal side is continuous with higher resistance between two of the terminals (suggesting a small-turns tap on the 3rd pin). I do not know if there's an internal capacitor. There's "infinite" resistance between the two sides. See references below for more confusion.
Neil Cherry (of Idiot's Guide to Home Automation) said to me: "Here's what I recall about the GI Pico chip: it was an analog shift register. It lived in the live AC section of the TW523 [made by X-10]." Google searched Wikipedia's X10 entry and Google's AI said: "The original X10 custom ICs - developed by Pico Electronics of Scotland (the pioneer engineers who laid the foundation for the X10 protocol in the mid-1970s) - were manufactured under contract by General Instrument (GI). " Wikipedia gives a brief history of X10 development which began at Pico.
The GI chip as described, is on the AC circuit, and may have its ground side on the AC line. So any use of AC power equipment on the GI chip under those conditions could cause an AC to ground short with disasterous, DANGEROUS results. Looking at the TW523 schematic in the "technical note" below, there's a 70348 IC with 24 pins. That may correspond to the GI/PICO 28-pin chip on the Scitronics #2 board. Other components on the TW523 schematic may correspond to the other AC side components on this Scitronics board. The IF transformers appear to have different windings.
I conclude, this Scitronics board with GI PICO IC, is probably an earlier version of the Scitronics X-10 controller and includes a PICO/GI IC product and Toko IFTs. - Herb Johnson
I found a photo of the Scitronics Inc Real Time Clock S-100 board. I do not have this board. The board uses an OKI brand MSM5832 time of day clock chip, accessed by a Motorola 6821.
X-10 power-line networed AC control was around for decades from the 1980's. Here's a tech note from X10 about their PL513 and TW523 power line interfaces and how their networking protocol worked. These interfaces use a transistor and IF Transformer (can-like devices) KC1047 to connect to the power line, "like" the Scitronics #2 board above.
Further Web and book and article search will find X-10 content that's a few decades old (1980's to early 2000's). Computer/electronics magazines of 1980 ish will find ads for Scitronics products.
French Web site by Laurent Deschamps about X-10 technicals. Some content is in English, including a TW523 article.
There's an X10.com Wiki site on X-10 branded modules, which were licensed for manufacture by a number of compaines including Radio Shack. I do not know who owns this Web domain but they (apparently) work out of Texas and offer X-10 modules. I find lots of old X-10 tech in thrift stores which have large consumer electronics sections. Also can be found in hamfests (look it up).
The deramp.com MFE archives has a folder for Scitronics. They show the Remote Controller like the #1 model I have. Also they show a Scitronics RTC, or real-time (of day) clock S-100 board.
There may be a Scitronics product for the Apple II, but I haven't found it. They did produce an Apple II "RTC" or Real Time Clock board (time of day) and something called an "Encased Controller" that can be connected to an "Apple II, TRS-80, etc.". (From small ads in Byte, etc. in 1981.)
There are X-10 products for the Apple II, a Mountain Hardware board Introl/x-10(tm). Mountain Hardware also had an X-10 S-100 "AC controller" board. An Apple II book "Micro Mansion - Using your computer to have a safer more convenient home" by Bonynge, had this SciTronics description:
"SCI-Tronics offers three S-100 Bus, IEEE-696 compatible boards each including manuals and software is available (extra) for integrated applications between the boards. The Real Time Clock board can track hours, minutes, seconds, day of week, month, and day of year ($199). The Energy Watcher board measures electrical power usage ($259). Similar more sophisticated EW boards available. An X-10 and Leviton (commercial grade X-10 type system) Remote Controller board is available for $259. - Sci-Tronics Inc. 523 S. Clewell St. P.O. Box 5344 Bethlehem, PA 18015"
Information on the X-10 brand TW523 is this PDF of the manual. It uses a KC1047 and a KC1042, which by the schematic is a 3-winding transformer (those little cans) designed for 120KHz X10 frequencies. Web search finds discussion which suggests "Sumida P/N 159-10100040, Sumida Type P-7GB, DWG. NO. HKS-753-013" The data sheet on that transformer. However this data sheet is for a two-coil transformer and the KC1047 and KC1042 are three-coil transformers.
Meanwhile, the IF Tranformers on the Scitronics board are marked "Toko RCL". They measure 10.5mm square. Toko is/was a brand of inductors, later acquired by Murata. some discussion about how to identify Toko IFTs is in this series of posts. Aparently these IF cans are Toko "10K" packages or "5A, 5M, 5S" packages
Apparently, people playing with old RF equipment keep looking for data on these IF tranformers and coming up empty. Measurements for these include grid-dip meters to determine resonant frequencies for L/C circuits, and inductance meters to get the inductance.
Copyright © 2026 Herb Johnson
