This article follows Part 1 of the Tandy Corporation’s history, which covers the company’s founding and the lead up to and launch of the TRS-80.
TRS-80 press release:
The latest development in electronics for the home, according to Radio Shack, is a complete, low-cost microcomputer system.
Just introduced by the nationwide electronics store chain is the new Radio Shack TRS-80 Microcomputer System. Not a kit, the TRS-80 comes completely wired and tested, ready to plug in and use.
Uses for the microcomputer around the home could include personal finance management and evaluation of investment portfolios. In the kitchen the TRS-80 may be used for storing recipes, keeping a running inventory of groceries, menu planning and converting recipes for larger or smaller servings than usual.
For the student in the home, the TRS-80 can be used as an aid to learning mathematics, music theory and virtually any subject through programmed teaching methods. And, just for fun, a variety of game programs will be available, including blackjack and backgammon.
Tandy had grown from a leather shoe-findings company into a hobby company, and then became the parent company of Radio Shack. With the arrival of microcomputers, the company launched the TRS-80. Given the company’s retail presence, price target, ease of setup, and expansion capabilities, the computer quickly took the lead in the early microcomputer market.
Tandy Corporation’s leadership hadn’t expected demand to be so strong. They rather had expected the computer project to fail completely. The initial production run of 3500 units sold out immediately. While the company worked to ramp up production, the computers could be purchased with a $100 deposit. After production was increased, around 100,000 TRS-80s were sold by the end 1978. Tandy’s top brass showed some humility (or at least business sense) and completely pivoted the company to computing as a result. With the company’s new focus, they opened dedicated computer centers, the first of which was located in the Tandy Center in Fort Worth.
Radio Shack was certainly still the primary outlet for Tandy computers, but these dedicated computer centers, call centers, and staff demonstrated the company’s commitment to the industry.
Philip North was a childhood friend of Charles Tandy, had served as his administrative assistant, and it was North who took over Tandy Corporation as interim president and CEO on the 5th of November in 1978. He largely continued Tandy’s management style and practices while leaning on the company’s executive VP, John Roach, for technical matters.
Further surprising Tandy Corporation’s executives, the TRS-80 had some demand from the business sector for which the computer hadn’t been designed. This demand spurred the development of a more powerful machine, the TRS-80 Model II. This was a very different machine from its immediate predecessor. First, the Model II featured a 4MHz Zilog Z80A, and a base RAM capacity of 32K. Alone, this was a serious advancement over the Model I’s Z80 at 1.77MHz and just 4K RAM, but Tandy didn’t stop there. The computer had a detachable keyboard with function keys and a numeric key pad. The Model II had DMA, vectored interrupts, port-based instead of memory mapped I/O, two RS-232 ports, a Centronics port, and three internal expansion slots. The computer also lacked BIOS ROM and made use of a floppy disk for booting into TRSDOS. While this made the computer incompatible with the Model I, these changes made the computer far more suitable for CP/M. As for floppy drives, the standard drive included was the Shugart SA-800 (full height, single-sided, eight inches), but the system could accommodate four drives.
Video was different on the Model II from that of the Model I as well. The most obvious difference was that the CRT was of higher quality and integrated into the main computer housing. Display was 80 columns by 24 lines, and it included lower case letters, currency symbols, and symbols for mathematics. Less obvious, all of the main system RAM could be banked for use by the video system meaning that 512K video RAM was available if needed as the Model II could be upgraded to 512K. If the graphics expansion board were added, the Model II gained pixel-addressable graphics at a resolution of 640 by 240. This expansion included a BASIC that provided the ability draw, and it provided dedicated video RAM with ability to transfer data between system RAM and video RAM.
Beyond the graphics expansion, the Model II had hard disk controllers, network adapters, RAM expansions, and I/O expansions available. Tandy also made sure that their customers would be supplied with software both general and specific. More generalized offerings were programs like General Ledger, Inventory Control System, Payroll, Accounts Receivable, Mailing List, Model II Scipsit (word processor), and VisiCalc. More specialized software included Medical Office System, Manufacturing Inventory System, COBOL, FORTRAN, MACRO-80 assembler, Compiler BASIC, and Profile II.
The TRS-80 Model II was introduced in May of 1979 and was generally available by October of 1979. By August of 1982, the Model II had achieved just 10% of the Model I’s success. Given that the Model II could be priced at more than $8000 which would be roughly $35,350 in 2025 dollars… this actually isn’t as bad as one would think. The entry level price was $3450 which would be something around $15,000 as of this writing. That’s quite a bit of cheddar, and Tandy wouldn’t have needed many sales to get rather high revenues. By the end of 1979, the company had sold over 200,000 computers (Model I and Model II combined), and total revenues from computers had passed $500 million.
For Tandy, the Model I was their single most important product, and the FCC had an issue with it. Under 47 CFR Part 15, the FCC classified the Model I as a Class B device meaning that it was marketed for use in a residential environment notwithstanding use in other environments. Regulations regarding such electronic devices were set to begin on the 1st of January in 1981 for devices manufactured on or after that date, and the Model I produced quite a bit of RF… enough that it would interfere with AM radios if they were close enough, and this violated the regulation. Tandy ceased production of the Model I in late 1980, but they also obtained an exemption for the manufacture of 30,000 Model I Expansion Units in 1981. The company needed a new machine to fill the same market segment, and they needed it quickly.
On the 31st of July in 1980, that replacement machine came in not one but three machines. The most direct replacement was the TRS-80 Model III which brought dual floppy disk drives into a dumb-terminal-like all-in-one enclosure. The company added the TRS-80 Color Computer, or CoCo, to the line up, and introduced the TRS-80 Pocket Computer I.
The Model III could read and convert floppies from the Model I, but the reverse was not true, and the differences in ROM meant that most programs would require some modification to run on the Model III. The Model III was built around the Zilog Z80A at 2.0MHz, had 16K RAM standard with a maximum of 48K, had 14K ROM, could output either 32 or 64 columns with 16 rows, had 128 graphics characters, upper and lower case text, monochrome only output, and shipped with one or two floppy disk drives (double density). Many peripherals were available for the machine, but standard ports included tape (500 or 1500 baud), Centronics, and RS-232. For operating systems, Tandy made TRSDOS 1.3 for the Model III, but ports of NEWDOS, DOSPLUS, LDOS, and MULTIDOS were also available.
The Tandy TRS-80 Color Computer was intended for the home segment like the TRS-80 Model I before it, the name certainly carried that legacy, but all similarities ended there. The CoCo was built exclusively from Motorola ICs. Rather than the Zilog Z80, the CoCo used a Motorola MC6809E. Why is this machine so very different? There’s a hint in that soon after launch, Tandy introduced a modem for the machine.
In 1977, Motorola, Tandy, the Kentucky Cooperative Extension Service, and the University of Kentucky College of Agriculture teamed up to build a video text system providing nearly real-time information about the operation of a farm via an integrated modem. The first prototype Green Thumb terminal was made in 1978 using the MC6847 Video Display Generator and MC6809 CPU. This was released as the VIDEOTEX by Tandy, and the AgVision by Motorola.
With the CoCo, Tandy removed the modem and replaced it with a cartridge slot, added I/O ports and joystick slots, moved the power supply into the computer’s case, and put Color BASIC on the ROM. The modem and VIDEOTEX software were then sold separately for owners of a CoCo, but there were three distinct VIDEOTEX products released anyway. The VIDEOTEX Software package sold for $29.95, and included a CompuServe user guide, ID and password for CompuServe, one hour complimentary CompuServe time, and one hour complimentary Dow Jones Information Service time. This required the user to purchase a modem for his/her TRS-80 or Apple II. The VIDEOTEX terminal was similar to the CoCo with aforementioned differences and priced at $399. For the VIDEOTEX Network System priced at around $20,000, the Radio Shack catalog stated:
The TRS-80 VIDEOTEX Network System is a complete, low-cost data communications network designed for commercial, corporate, and private-interest applications. Now any organization can provide newsletters, industry news, medical or agricultural reports—virtually any information that requires up-to-the-minute status—to any member (or customer) equipped with our inexpensive TRS-80 VIDEOTEX Terminal. The System includes a Data Base to input and update information, a Store and Forward System to retrieve and forward desired information, and a Multiplexor that allows the system to handle up to 16 phone calls simultaneously.
Back to the CoCo itself, the very first Color Computer model featured just 4K RAM, a Motorola MC6809E running at 0.89MHz, Color BASIC in ROM, and cost $399. The 16K RAM model with Extended Color BASIC was listed at $599. This doesn’t sound impressive. A slow CPU and limited RAM? Well, the 6809 was quite a sophisticated CPU for its day, and it would have held its own against a 2MHz Z80. Compared to the VIC-20 or the Atari 400, the CoCo had a more powerful CPU and equivalent RAM. Of course, the CoCo cost $100 more than the VIC-20 and $150 less than the Atari 400. Later versions of the Color Computer would offer 32K or 64K RAM, and by the end of the machine’s life both the 4K and 32K models had been discontinued with just the 16K and 64K models remaining. As one would expect, the price on the CoCo also fell overtime.
To keep costs down, the entire computer, including the PSU, was built on a single PCB housed in a single casing with the keyboard and all I/O ports. The machine had a keyboard of 53 keys including arrow keys, break, and clear. While the ROM allowed for only upper-case text with output of 32 columns and 16 lines, it had multiple graphics modes: 32x16 with four colors, 256x192 with two colors, 128x96 with eight colors, and 128x192 with four colors. Given the name “Color Computer,” the graphics modes are not surprising, and a total of eight colors were available with two preset four color palettes. For audio, the computer had a 6-bit DAC which also served the cassette interface. The only video output was to a television, but the machine was outfitted with RS-232, a cassette adapter port, two joystick ports, and a cartridge slot. The RS-232 port saw quite a bit of use with floppy disk drives, drawing tablets, speech and sound generators, and printers.
At launch, there wasn’t much software available with just nine Program Paks being listed in the catalog. Naturally, this changed quite quickly. The platform gained a large number of games, educational titles, and productivity titles in cartridge, cassette, and floppy.
The TRS-80 Color Computer, despite lagging behind competitors in market share, was successful enough to have inspired clones. Perhaps the most famous were the Dragon 32 and Dragon 64 made by Mettoy in Wales. Despite being clones, the Dragon machines improved upon the original with the addition of a parallel printer port, and a 5-pin DIN for composite monitor output. Another clone was the TDP-100 or Tandy Data Products System 100 which was made by Tandy but marketed by RCA. Tandy also made the TRS-80 MC-10 or Micro Color Computer. This was a competitor to the Timex Sinclair 1000, and featured a less powerful 6803 CPU and maintained 4K RAM. The MC-10 also lacked joystick ports and the cartridge slot, and the keyboard picked up Sinclair’s habit of having entire BASIC commands in single keys. The MC-10 didn’t do well. I’ve seen several sources claim that the Fujitsu FM-7 was a TRS-80 Color Computer clone, but this is inaccurate. While the FM-7 uses the same CPU and a similar BASIC, the FM-7 uses a second 6809 for video instead of the 6847, and it uses the AY-3-8910 for audio.
The third machine of the 31st of July in 1980, the TRS-80 Pocket Computer, was the first computer branded by Tandy Radio Shack that was not of their own design. This was a rebadged Sharp PC-1211 with all of the advantages and shortcomings of the Sharp retained. The machine used two 4bit CPUs (SC43177, SC43178) clocked at 256kHz arranged serially, had 1.9K RAM available to the user, and could accommodate BASIC programs of around 250 lines. The display was a 24 digit dot matrix LCD, and the only audio on offer was a simple beeper. For the time period, calling this a computer would mean having some kind of I/O to accompany the programmability, and the Pocket Computer could be used with a printer and tape drive to meet that requirement. This tiny little machine measured 6 and 7/8 inches by 2 and 3/4 inches by 11/16 of an inch, and it was powered by four PX675 mercury button cells giving the machine 300 hours of run time.
At the time of introduction, the Pocket Computer was listed for $229. By late 1981 or early 1982, the price had fallen to $149, and by late 1982 or early 1983 the price had fallen to just $127.95. While there were some third party software packages for the TRS-80 PC, Radio Shack was the main purveyor with titles like Real Estate, Math Drill, Engineering Math 1, Surveying, and even some games collections which featured titles like NIM, Space Ship Landing, and Treasure Hunt.
According to InfoWorld, during a photo shoot for the Asimov Pocket Computer ads, a Radio Shack employee asked Asimov: “How close is that to the computer you described in the first volume of the Foundation trilogy?” Isaac Asimov looked at the computer for a bit, then nodded and said “this is it.”
Tandy Corporation had survived their pivot to computing, survived a leadership change, and survived fierce competition. The company was strong, and they were moving quickly to provide products for each segment of the computer market, at each price point that they could manage. While the company had held around 60% of the market earlier, they still managed to hold 40% by the close of 1980.
I strive to provide accurate historical accounts despite this not being an academic publication. Many of you, my dear readers, were present for events I cover, worked for, owned, or led companies I cover. All corrections are welcome. Thank you for your continued support.