TRS‑80.org


Games by Wayne Westmoreland and Terry Gilman

Wayne Westmoreland and Terry Gilman wrote some excellent games for the TRS‑80 from 1981 to 1983, including Sea Dragon and Armored Patrol. In 1995, Wayne Westmoreland released all of those games into the public domain. You can download the disk of games here: AIGAMES.ZIP

Here is a description, written by Wayne Westmoreland in 1995, for each file on the disk.

TSHORT

After upgrading their TRS‑80 Model I to Level II BASIC, many people missed the “shorthand dialect” of Level I BASIC. TSHORT was a very popular keyboard macro utility for Level II BASIC that added a similar kind of shorthand for BASIC commands. It was written by Ron Wirth and released in 1979 by Web Associates for $9.95. (The name Web Associates was not a reference to the World Wide Web, which it predated by ten years.) TSHORT ran in high memory above BASIC and consumed only 580 bytes of memory.

Was the TRS‑80 once the top-selling computer?

It is often stated that the Apple II dominated the computer market from its introduction in 1977 and that the TRS‑80 and other competitors remained only minor players. Although often repeated, the numbers don’t bear out this assertion. Apple sold around six million Apple II’s between 1977 and 1993, but sales started slowly and built up over time.

Concrete figures for computer sales from that period are hard to come by, but Jeremy Reimer researched and compiled totals for his article about the subject: Personal Computer Market Share: 1975-2004. I prepared this graph representing his totals for 1977 to 1980:

The Mikrokolor Color Graphics Interface

The Mikrokolor was a color graphics interface for the TRS‑80 Model 100 that was sold by Andreasen’s Electronics Research & Development, Inc. The Mikrokolor hardware was designed by Paul Andreasen, the digital interface and graphics routines created by James Cole, and the software written by Andrew Baird. Andreasen’s Electronics Research & Development also sold versions of the Mikrokolor for the Model I, III, 4, and 12 and also the S-100 bus and the Apple II. There was also a $54.00 VHF modulator for the Mikrokolor that operated on channels 7 to 10.

The Mikrokolor fit into much the same category as the later Disk/Video Interface sold by Radio Shack, allowing a Model 100 to be used with a separate monitor. Unlike the Disk/Video Interface, which was black and white only, the Mikrokolor displayed in color.

The Archbold Speedup Board

The TRS‑80 Model I ran at a speed of 1.77 MHz. That speed was quite fast for a microcomputer at the time, but almost immediately people began designing speedup boards to increase it. The most famous of those speedup boards was the Archbold Speedup Board, designed by Bill Archbold and sold by Archbold Electronics.

The Archbold Speedup Board itself was a fairly small board (1.5" by 2.5"). It came with an instruction manual containing complete installation directions, including a photo of the Model I logic board. The exact installation procedure varied depending on the hardware installed but involved soldering wires to various points within the Model I and cutting a few traces.

One novel feature of the Archbold unit was that the speed could be software controlled (through I/O port 254) rather than using a hardware switch. That control scheme was copied by other speedup boards and became the de-facto standard for Model I speed control. Many programs, including Super Utility Plus, included code to automatically change the speed on the Archbold Speedup Board. It was also possible for users who wanted a manual switch to install one, but no switch was included with the Archbold package.

Level I BASIC

When the TRS‑80 Model I was first released in 1977, the BASIC interpreter that Microsoft was writing, Level II BASIC, was still months away from completion. Instead the Model I originally shipped with a BASIC interpreter known as Level I BASIC.

Level I BASIC was based on “Palo Alto Tiny BASIC”, a 2K version of Tiny BASIC written by Dr. Li-Chen Wang for the May 1976 issue of Dr. Dobb’s Journal. Because Dr. Li Chen-Wang placed his BASIC in the public domain (he labeled it “@COPYLEFT; ALL WRONGS RESERVED”), Steve Leininger, the designer of the TRS‑80, was able to use it as a starting point. He added floating point math, cassette, keyboard, and video routines, doubling the size of the original code to 4K.

The Holmes Internal Memory

Although the TRS‑80 Model I supported up to 48K of memory, there were only sockets for 16K within the Model I itself. The only official way to add more memory was to buy the Radio Shack Expansion Interface, which had sockets for an additional 32K of memory, for 48K in total. The Expansion Interface (without any memory) cost $299, making any kind of official memory expansion very expensive.

The other important feature of the Expansion Interface was the built-in floppy disk controller. But not everyone was interested in or could afford floppy drives, which cost hundreds of dollars per drive. Many people used cassettes or other alternative storage devices, such as the Exatron Stringy Floppy, the TC-8, or the BETA-80. What option was there for the Model I user who wanted to maximize memory but without the extras (and expense) of the Expansion Interface?

One answer was the Internal Memory, introduced by Holmes Engineering in 1981. Designed by Larry Holmes, the Internal Memory added memory entirely inside the Model I without requiring an Expansion Interface. It could be easily installed by the user without any soldering or trace cutting. The Internal Memory came in three versions:

The Radio Shack “expansion box”

The TRS‑80 Model I was designed to allow for external expansion through what Steve Leininger described as an “expansion port” (the TRS‑80 card edge connector). Many people assumed that Radio Shack was developing a S-100 based expansion box to attach to the Model I. (The S-100 was a popular bus standard at the time.)

The first issue of the Radio Shack Microcomputer Newsletter in late 1977 contained a section answering some common questions about the new TRS‑80 computer. One answer gave some details about the upcoming “expansion box”:

No-Fuss Any-Speed Hardware – The Cassette Gazette Page 14

The Cassette Gazette was a 1983 one issue advertising newsletter that was a joint production of Lemons Tech and KWIK Software. The Gazette described the products sold by the two companies, mixed in with operational advice and interesting facts about using cassettes with your TRS‑80. It appears to have been written by Wayne Lemons, the […]

TRS‑80 Cassette Software – The Cassette Gazette Page 13

The Cassette Gazette was a 1983 one issue advertising newsletter that was a joint production of Lemons Tech and KWIK Software. The Gazette described the products sold by the two companies, mixed in with operational advice and interesting facts about using cassettes with your TRS‑80. It appears to have been written by Wayne Lemons, the […]