Plug ‘n Power

Plug ‘n Power was Radio Shack’s brand name for products that used the X10 power line communications protocol. X10 was developed in 1975 by Pico Electronics, Ltd. of Glenrothes, Scotland. Radio Shack, along with Sears, Roebuck & Co. (with the Sears Home Control System) and BSR (with the BSR System X-10), was among the first sellers of X10 compatible products.

Radio Shack introduced their first Plug ‘n Power products in late 1979. Most of the products were appliance and light modules. These plugged into an electrical outlet, and an appliance or light was then plugged into the module. Some of those modules included:

  • Appliance Module (catalog number 61-2681) cost $16.99 (originally $15.99)
  • Lamp Dimmer Module (catalog number 61-2682) cost $16.99 (originally $15.99)
  • Universal Appliance Module (catalog number 61-2684) cost $17.99
  • Wall Switch Module (catalog number 61-2683) cost $17.99
  • Wall Outlet Module (catalog number 61-2685) cost $21.95

The modules were designed to respond to commands sent over the electrical wires inside the house. They could turn on or off, or in the case of a lamp, change brightness. The advantage of using a power-line communication system was that it didn’t require any additional (and costly) signal wiring.

The TRS‑80 Screen Printer

The TRS‑80 Screen Printer (catalog number 26-1151) was the first printer Radio Shack sold for the TRS‑80 Model I. It was introduced in March 1978 for $599.00. As the name suggested, the Screen Printer could print only one thing: the contents of the TRS‑80 screen.

The Screen Printer was a very compact unit, not much larger than the four-inch wide “electrosensitive paper” that it printed on. It had a “PRINT command switch” on the front of the unit. When that switch was pressed, the entire contents of the TRS‑80 screen (including graphics) were printed out on the aluminum-coated paper in around two seconds.

Unlike most other Radio Shack printers, the Screen Printer didn’t connect to the line printer port on the Radio Shack Expansion Interface. The Screen Printer connected directly to the bus card-edge connector on the Model I or on the Expansion Interface (also known as the Screen Printer connector).

The Shuffleboard

The Shuffleboard and Shuffleboard III were CP/M hardware add-ons for the TRS‑80 Model I and Model III. Although somewhat different products, each allowed unmodified CP/M programs to run on the TRS‑80 by “shuffling” the TRS‑80 memory map into one acceptable to CP/M.

Both the Shuffleboard and Shuffleboard III were created by Parasitic Engineering, but the Shuffleboard III achieved most of its popularity after Memory Merchant took over the product.

The original Shuffleboard was actually a companion to another Parasitic Engineering product, an 8″ drive interface called the Maxi-Disk. Howard Fullmer and Gene Nardi created the Shuffleboard and Maxi-Disk and introduced them in May 1979 at the Fourth West Coast Computer Faire in Los Angeles, California.

The $995.00 (later $1079.00) Maxi-Disk consisted of two parts:

The MISOSYS Hard Drive Kit

The MISOSYS Hard Drive Kit was a hard drive interface for the TRS‑80 Model III, Model 4, and Lobo MAX‑80. (There was no version for the TRS‑80 Model I.) It was announced in the Spring/Summer 1989 issue of The MISOSYS Quarterly and began shipping in September 1989. It came in in two configurations: 20 MB and 40 MB.

Although Roy Soltoff described the MISOSYS Hard Drive Kit as a “pre-assembled kit,” it came fully assembled, tested, and ready to connect to the TRS‑80. The only other item needed was the “host interface cable” which cost $20.00 extra originally but was later included in the package.

The complete unit was housed in a 5.5″ high, 7″ wide, and 15″ deep case, which had room for two half-height drives. The case contained a 60-watt power supply and fan. The shipping weight of the entire package was 20 pounds.


Scripsit was the product name that Radio Shack used for their word processors for TRS‑80 computers. Over the lifetime of the TRS‑80, Radio Shack created versions of Scripsit for practically every TRS‑80 computer model sold. With only a few exceptions, the different Scripsit programs offered different features and capabilities.

Scripsit was described by 80 Micro magazine as “the overwhelming choice of TRS‑80 owners.” Since the TRS‑80 was the top selling computer in the early days of microcomputers, Scripsit was a very popular word processor. As late as 1984 (according to the market research firm InfoCorp), Scripsit was still the third most popular word processor across all computers (not just the TRS‑80).

Both Model I/III Scripsit and Model II Scripsit won the 80 Micro Reader’s Choice Awards in 1982 and 1983. (Color Scripsit came in second both years.) Model I/III Scripsit was one of only five programs inducted into the 80 Micro Hall of Fame in 1983.

BASIC Computer Games

BASIC Computer Games (ISBN 0-89480-052-3) was the first and most popular of a category of books containing games written in BASIC for typing into a computer. It was also the first computer book to sell more than a million copies. Many people took their first steps as programmers by typing in and modifying the programs in this book.

BASIC Computer Games and its sequel, More BASIC Computer Games (also known as BASIC Computer Games Volume II) were created by David Ahl, the founder and publisher of Creative Computing magazine. Both books were very popular and were translated into German (BASIC Computer Spiele and BASIC Computer Spiele: Band 2), French (Jeux D’Ordinateur en BASIC and Nouveaux Jeux D’Ordinateur en BASIC), and a three-volume Danish edition (BASIC Computerspil). Both BASIC Computer Games and More BASIC Computer Games had TRS‑80 specific editions that were sold both by Radio Shack and Creative Computing Press.

The 80 Micro Young Programmer’s Contest

For three years starting in 1982, the TRS‑80 magazine 80 Micro held a contest to encourage young people to program. It was known as the “80 Micro Young Programmer’s Contest.” Anyone under the age of 18 could submit a program for a chance at winning prizes. 80 Micro published the winning contest entries in the February issue each year.

The entries, which numbered over 200 the first two years, were judged by the 80 Micro editorial staff based on five categories: programming elegance, documentation, originality, error-trapping, and usefulness. Most of the winning entries were written for the TRS‑80 Model I and III, but there were also several for the Color Computer, and even one each for the Model II, Model 4, and Model 100.

The Holmes Sprinter

The Holmes Sprinter was a family of speed-up boards for the TRS‑80 Model I and III. They were created and sold by Holmes Engineering, Inc., a company responsible for many hardware add-ons for the TRS‑80, such as the Expansion Mainframe, the VID-80, and the Internal Memory. The Sprinter models were probably the most popular speed-up boards available for the Model I and III.

The Sprinter I for the TRS‑80 Model I was introduced in late 1981. It cost $99.50, which was more expensive than its primary competitor, the Archbold Speedup Board. However, the Sprinter I had one big advantage over the Archbold Speedup Board: it could be installed with no soldering at all. Installation required just a few steps:

Kilobaud Microcomputing

Kilobaud Microcomputing was a hobbyist computing magazine that began in 1977. It was created by Wayne Green, who was known for publishing the magazines 73, BYTE, and later 80 Microcomputing. Kilobaud Microcomputing was aimed more at the beginning computer hobbyist than other similar magazines. It is perhaps best known for spinning off 80 Microcomputing, the most popular TRS‑80 magazine.

The magazine was originally named Kilobaud when it began in 1977. That changed to Kilobaud Microcomputing by the January 1979 issue. The word “Kilobaud” on the cover became smaller and disappeared entirely in 1982. The magazine was then called Microcomputing until it ended in 1984.

The Omikron Mapper

The Omikron Mapper was the first (and probably most popular) CP/M hardware add-on for the TRS‑80 Model I and Model III. It allowed unmodified CP/M programs to run on a TRS‑80, something not normally possible. The Omikron Mapper was introduced in 1979 by Omikron Systems, a Berkeley, California company run by George Gardner.

Omikron Systems sold three versions of the Omikron Mapper from 1979 to 1984:

  • The original Omikron Mapper I was for the Model I. In 1979, it cost $169 for a version that could use 5¼″ floppy drives. A version that could use 8″ drives cost $199.
  • The Omikron Mapper II was a data separator that allowed a Model I with Expansion Interface to run CP/M using a combination of 5¼″ and 8″ drives. In 1980, it cost $99. Omikron originally bundled the Mapper I as part of the Mapper II, but later sold them separately. In addition to CP/M, NEWDOS/80 could also use the Mapper II to access 8″ drives.
  • The Omikron Mapper III was for the TRS‑80 Model III. Unlike the Mapper I, it only supported 5¼″ drives. It cost $199 in 1983.