The Custom TRS‑80 and Other Mysteries
Tiny Pascal, also known as “Tiny” Pascal, was a popular programming language for microcomputers. It was created by Kin-Man Chung and Herbert Yuen in 1978 and first described in a three-part series of articles published in BYTE. There were at least four different versions of Tiny Pascal for the TRS‑80, although the version sold by Radio Shack was the most popular.
Tiny Pascal was a subset of the programming language Pascal. It contained most of the features of Pascal but was small enough to run well on a cassette-based TRS‑80. Tiny Pascal was often used to teach Pascal programming and the Radio Shack catalog described it as a “great introduction to structured programming.”
The first version of Tiny Pascal appeared in a three-part series of articles in BYTE titled “A ‘Tiny’ Pascal Compiler.”
Data communications can materially expand your computing horizons. It means you can communicate with large “data base” computers, using your TRS‑80 as an intelligent peripheral.
There were two versions of the Telephone Interface: the $149.00 Telephone Interface I (catalog number 26-1170) which was introduced in 1978 and the $199.00 Telephone Interface II (catalog number 26-1171) which replaced it in 1979.
The TRS‑80 System Carrying Case Set (catalog number 26-500), also known as the Model I Carrying Case Set, was Radio Shack’s solution for transporting a TRS‑80 Model I. It was introduced in late 1978 for a price of $69.95. Radio Shack increased the price to $75.00 on July 1, 1980 except for a brief sale price of $39.95 that ended December 31, 1980.
Although the Model I wasn’t a portable computer (by any stretch of the imagination), people often needed to move a Model I to a new location. For example, many people kept their Model I at work during the week and brought it back home for the weekend.
The TRS‑80 System Carrying Case Set was two cases designed to hand transport a Model I keyboard unit, video display, and associated parts.
The Color Graphics Interface from JFF Electronics was one of the first color add-ons for the TRS‑80 Model I. It cost $49.95 when it was introduced in early 1979 by JFF Electronics Ltd of Saskatoon, Canada. The Color Graphics Interface didn’t require a Radio Shack Expansion Interface but plugged directly into the Model I 40-pin expansion bus. It didn’t include an enclosure but was a bare circuit board. However, it did include a regulated power supply on the board.
The Color Graphics Interface could be connected to either a color monitor or a color television set. It supported several different modes:
- a text display with two colors and reverse video
- a 64 by 192 mode with eight colors
- a 128 by 192 mode with four colors (in two sets)
- a 256 by 192 mode with two colors
TRS‑80 Computing, also known as S-80 Computing, was an early newsletter for the TRS‑80. It was published by Computer Information Exchange (also known as CIE) from 1978 to 1980. It cost $1.50 per issue or $15.00 for twelve issues. Although not very many issues of TRS‑80 Computing were published, it was a highly regarded TRS‑80 newsletter, described by Recreational Computing as “a top-rated publication.”
Computer Information Exchange was an educational nonprofit corporation that was based in San Luis Rey, California and founded by Bill McLaughlin. It sold a variety of low-cost TRS‑80 software on cassette, mostly of an educational nature. Their most popular product was People’s Pascal, an implementation of the Tiny Pascal compiler that was created by Kin-Man Chung and Herbert Yuen. Computer Information Exchange sold two versions of People’s Pascal:
The Microtronix Expandable Interface was probably the first third-party alternative to the Radio Shack Expansion Interface for the TRS‑80 Model I. It cost $129.95 when it was introduced in late 1978 by Microtronix of Philadelphia, Pennsylvania. According to the product announcement in H&E Computronics, the Expandable Interface was also available in kit form for around $100.00.
Microtronix sold software and hardware for the TRS‑80 (as well as the Apple II and Commodore PET), including the Electric Pencil lowercase modification and a 16K RAM expansion. They demonstrated the Expandable Interface at the Personal Computing ’78 show, which was held in 1978 in Philadelphia from August 25th to 27th. The Expandable Interface had an unusual set of features:
The XRX was an official hardware modification from Radio Shack for the TRS‑80 Model I. It installed inside the Model I and made it easier to load programs from cassette using Level II BASIC. Radio Shack dealers would install the XRX for free on any unmodified Model I. (For owners with a modified Model I, the installation price could range from $30.00 to $50.00.) Model I’s built after the XRX was introduced included it as a standard feature.
The original version of the modification, usually called the XRX or XRX-1, was introduced in early 1979. At the time, Radio Shack only called it “the modification.” Because it wasn’t a named product with a catalog number, it was known by many names by users, including XRX, XRX-I, XRX-II, XRX-III, XRX2, XRX3, XRS-2, and X2X. These were all different names for the same modification.
Invasion Force (catalog number 26-1906) was one of the first action games Radio Shack published for the TRS‑80 Model I. It was written by Robert Arnstein and introduced in 1979 on cassette for a price of $14.95. There never was a disk version of Invasion Force. Radio Shack also released a game for the PC-2 named Invasion Force (catalog number 26-3705), but it had only a loose connection to the Model I/III version.
Invasion Force was very similar to Trek-80, a game for the Sol-20 computer that was probably also written by Robert Arnstein. Here is a description of Invasion Force from an article titled “A New Real-Time Space Adventure That Puts You in Command of Your Own Starship” from the June 1979 issue of the TRS‑80 Microcomputer News:
Take command of the USS Hephaestus and protect the galaxy against the hated and feared Jovians. The Command Control Display (TRS‑80 screen) places all the ship’s resources at your fingertips.
The TRS‑80 Pocket Computer 2 (catalog number 26-3601), better known as the PC-2 (and even the Pocket Computer II in some early articles), was the most powerful member of Radio Shack’s family of Pocket Computers. The PC-2 wasn’t a replacement for the original Pocket Computer (known as the PC-1), but served as a more advanced (and more expensive) alternative.
The PC-2 cost $279.95 when it was introduced in 1982, but that price dropped to $199.95 by the following year. It was the only Pocket Computer that had speed and memory capacity that was competitive with a contemporary desktop computer. The PC-2 wasn’t manufactured by Radio Shack, but was a rebadged Sharp PC-1500. It wasn’t compatible with any of the hardware or software Radio Shack sold for the PC-1.
The PC-2 was larger and heavier than the PC-1. It measured 7 11/16″ by 3 1/8″ by 1 1/16″, nearly one inch bigger in each dimension than the PC-1. It weighed 16 ounces (with batteries) compared to the six ounces of a PC-1.
Microsoft Adventure, introduced in December 1979, was the first game sold by Microsoft, Inc., which at the time was located in Bellevue, Washington. It was written by Gordon Letwin and was among the first four products sold by Microsoft Consumer Products, a new division created to sell software to consumers. Before that point, Microsoft primarily sold BASIC interpreters (such as TRS‑80 Level II BASIC) directly to manufacturers. Microsoft Adventure cost $29.95 and was available for the TRS‑80 Model I and the Apple II when it was released in 1979. It had unusually high system requirements for a game at the time; both the Model I and Apple II versions required 32K and a floppy drive.
Microsoft Adventure was a microcomputer adaptation of Adventure, also known as Colossal Cave or ADVENT, which was first written for the DEC PDP-10. Adventure was the first computer adventure game and became very popular on mainframe installations in 1977 and 1978.