Computers in my world

My introduction into computers

Tandy Corporation's home computer sold through their Radio Shack stores in the late 1970s and early 1980s. The line won popularity with hobbyists, home users, and small-businesses. Tandy Corporation's leading position in what Byte Magazine called the "1977 Trinity" (Apple, Commodore and Tandy) had much to do with retailing the computer through more than 3000 of its Radio Shack stores. Notable features of the original TRS-80 included its full-stroke QWERTY keyboard, small size, well-written Floating Point BASIC programming language, an included monitor, and a starting price of $600.

At the time the only home computers available to the general public were things like the Altair kits and the others mentioned above. In August 1977 Radio Shack, announced the TRS-80 microcomputer, with Z80 CPU, 4KB RAM, 4KB ROM, keyboard, black-and-white video display, and tape cassette for US $600. The Model 1 was first made available with a 4 kilobyte tiny BASIC in ROM, and either 4 or 16 kilobytes of RAM. The CPU board of the computer was contained in the keyboard unit, and *it used a separate black and white monitor. The monitor was really a RCA black and white TV without the TV tuner. The Level 1 BASIC was very limited. There were 26 integer variables available, A through Z, one single dimension integer array, and one or two string variables. Later, the ROM was upgraded to a 12K "Level 2" BASIC, which was much more advanced. Level 2 BASIC was actually useful to write real programs in, though all it supported for storage of programs and data was cassette tape.

Level 2 BASIC and 16K of RAM became the "standard" configuration. To get real use out of the Model 1, you needed the Expansion Interface, which would let you go above 16K of RAM to 32K or even 48K. It also had a provision for using two cassette tape units, a printer port, the floppy disk controller, and a serial port. Finally, it supplied the processor with a real-time clock interrupt that was used by the various DOS systems (and a couple of cassette based ROM enhancements) for time keeping functions. Microsoft had a Level III BASIC that loaded from cassette and made several useful additions to the standard BASIC.

The main problem with the machine was the interconnection between the keyboard and the expansion interface. It used a 40-conductor ribbon cable, and the connectors would get dirty quickly. There was nothing more frustrating than to have a large program typed in only to have the machine decide it wanted to reset itself. The other problem was flaky connections at the serial port board. All these contributed to the name "Trash-80". The interconnect problem was bad enough to give rise to several companies that sold gold-plated connectors that could be soldered to the machine.

First Release of the TRS-80

When theTRS-80 was released on August 3, 1977, no one in the press seemed to care about the TRS-80. The public, on the other hand, was obviously impressed. Soon, Radio Shack stores were flooded with orders--they were back ordered for months. In the first year, Radio Shack sold almost 55,000--even more than Leininger's prediction.

In May of 1979, Tandy released the Model II with a faster microprocessor and larger, higher capacity, single sided full height Shugart 8 inch disk drives storing 500K of data. This would become the first computer in the TRS-80 business line. The Model II is a computer system that was manufactured in the USA by Tandy between 1980 and 1984.

In July 1980, Tandy released the Model III. The Model III was little more than a Model I, expansion interface, monitor, disk drives, and power supply thrown into a single enclosure. It was the same CPU, but faster, had more memory, and the floppy drives held twice as much data, although the Model I could be upgraded to some of these features. This new design moved the computer from the hobbyists' realm into the plug- and-run realm more suitable for businesses and schools.

The Model 4, released in April 1983, was backward compatible to the Model III, but featured a faster CPU and better display (80 columns by 24 rows). It also included an updated DOS, which finally answered most users' complaints.

A Brief Chronology of Tandy Computers:

  • 1921: - Radio Shack begins as a one-store retail and mail-order company catering to ham operators and electronics buffs.
  • 1963: - Charles Tandy buys the chain of stores, and within two years turned a $4 million dollar loss into a $20 million dollar profit.
  • 1977: August - Radio Shack announces the TRS-80 Model I Microcomputer System Z80 $599.95 TRS-DOS
  • 1977: September - One month after launching the TRS-80, 10,000 are sold.
  • 1979: May - Tandy/Radio Shack announces the TRS-80 Model II, Z80 $3450 TRS-DOS.
  • 1979: October - Radio Shack begins shipping the TRS-80 Model II to users, Z80 $3699 TRS-DOS.
  • 1980: July - Radio Shack introduces the TRS-80 Model III, priced from US$700 to US$2500.
  • 1980: July - Radio Shack introduces the TRS-80 Color Computer, and sells for US$400.
  • 1980: July - Radio Shack introduces the TRS-80 Pocket Computer. Price is US$230.
  • 1981: January - Radio Shack ceases production of the TRS-80 Model I, and recalls units from the US market, due to failure to meet new FCC radio-frequency interference regulations.
  • 1982: January - Radio Shack introduces the TRS-80 Model 16, with 8-inch floppy drives, and optional 8-MB hard drive.
  • 1982: January - Radio Shack introduces the TRS-80 Pocket Computer, Model PC-2, for US$280.
  • 1983: March - Radio Shack announces its TRS-80 Model 100 portable computer. Price is US$799 for 8KB version, to US$1134 for the 32KB version.
  • 1983: May - Radio Shack introduces the TRS-80 Model 4, for US$2000.
  • 1983: October - Tandy/Radio Shack announces the "transportable" TRS-80 Model 4P, for US$1800.
  • 1983: Radio Shack introduces the TRS-80 Pocket Computer, Model PC-4, replacing the PC-1, for US$70.
  • 1983: Tandy releases the TRS-80 Model 2000, which uses the Intel 80186 microprocessor.
  • 1983: Radio Shack unveils the TRS-80 Model 12 at the CP/M '83 Show. Price is US$3200.
  • 1985: March - Radio Shack introduces the Tandy 6000 multi-user system. It features Z80A and 68000 processors, 512 KB RAM, 80x24 text, graphics, 1.2-MB 8-inch disk, optional 15 MB hard drive, TRS-DOS, or XENIX 3.0. It supports up to 9 users.

The IBM Computer World


The IBM Personal Computer, commonly known as the IBM PC, is the original version and progenitor of the IBM PC compatible hardware platform. It is IBM model number 5150, and was introduced on August 12, 1981. It was created by a team of engineers and designers under the direction of Don Estridge of the IBM Entry Systems Division in Boca Raton, Florida. When the PC was introduced in 1981, it was originally designated as the IBM 5150, putting it in the "5100" series, though its architecture wasn't directly descended from the IBM 5100. Rather than going through the usual IBM design process, a special team was assembled with authorization to bypass normal company restrictions and get something to market rapidly.

The first IBM PC ran on a 4.77 MHz Intel 8088 microprocessor. The PC came equipped with 16 kilobytes of memory, expandable to 256k. The PC came with one or two 160k floppy disk drives and an optional color monitor. The price tag started at $1,565, which would be nearly $4,000 today. What really made the IBM PC different from previous IBM computers was that it was the first one built from off the shelf parts (called open architecture) and marketed by outside distributors (Sears & Roebucks and Computerland). The Intel chip was chosen because IBM had already obtained the rights to manufacture the Intel chips. IBM had used the Intel 8086 for use in its Displaywriter Intelligent Typewriter in exchange for giving Intel the rights to IBM's bubble memory technology.


The original PC had a version of Microsoft BASIC - IBM Cassette BASIC - in ROM. The CGA (Color Graphics Adapter) video card could use a standard television set or an RGBI monitor for display; IBM's RGBI monitor was their display model 5153. The other option that was offered by IBM was an MDA (Monochrome Display Adapter) and their monochrome display model 5151.


The "IBM Personal Computer XT", IBM's model 5160, was an enhanced machine that was designed for business use. It had 8 expansion slots and a 10-megabyte hard disk (later versions 20MB). Unlike the model 5150 PC, the model 5160 XT no longer had a cassette jack. The XT could take 256 KB of memory on the main board (using 64 kbit DRAM).


The "IBM Personal Computer/AT", announced August 1984, uses an Intel 80286 processor, originally at 6 MHz. It has a 16-bit ISA bus and 20 MB (20 million bytes) hard drive. A faster model, running at 8 MHz, was introduced in 1986.

Most or all 5150 PCs had one or two 5-inch floppy disk drives. These floppy drives were either single-sided double-density drives (SS/DD, aka SSDD), or double-sided double-density drives (DS/DD, aka DSDD). The IBM PC never used single density floppy drives. The drives and disks were commonly referred to by capacity, e.g. "160KB floppy disk" or "360KB floppy drive", but because this is not entirely unambiguous, they are here referred to using the less commonly used but more accurate SSDD and DSDD terminology. DSDD drives were backwards compatible; they could read and write SSDD floppies. The same type of physical diskette could be used for both drives, however to convert a 5" SSDD disk to a DSDD disk, it needed to be reformatted, at which point SSDD drives could no longer read it.

I broke into computing in 1977

This started off as a hobby, and later turning into a profitable business. The TRS-80 Model I was my first computer. There were only Apple, Commodore and the TRS-80 available as personal comptuers. Atari had a kit and did lit tle more than play pong. It came with a BASIC programming language, a monitor, and a starting price of $600. It strained my budget, but I paid for it on layaway installments and in a few weeks had my own computer.

I joined some computer clubs in the area where we had swap meets to trade programs we had written and ideas. One group met at the Market Hall trade center in Dallas one Saturday each month and consisted of over 300 TRS-80 enthusiasts. I soon discovered a market for inventory programs and began writing and selling these programs. This was the start of my business. Advertising in the PC magazine soon brought business from all over the USA and Canada. Now, I was on a roll. One inventory program became two, then four, then eight, and eventually 30 different program packages for every inventory situation known in the business world. The business was run from a corner in our den.

Still there was a shortage of inventory programs and I had a big hold on the market. In 1982 IBM introduced their PC computer in 1981 and I bought one in 1982. I had to convert my MS-DOS programs to the IBM platform. Remember, Windows was a long way in the future.

By then I had started selling bar-code readers and cash drawers to work with the Retail Point of Sale programs Retail stores were going crazy to buy the setups.

In about 1983 I hired my son to help with sales and in about 1985 I moved into retail office space to continue expanding and hired another sales person. I had reduced the programs from 30 into about 12 really solid packages.

By 1990 I was on a roll with sales and custom modifications to these programs.

Microsoft released Windows 3.1 in March 1992 as a successor to Windows 3.0. Further editions were released between 1992 and 1994 until the line was superseded by Windows 95. I converted the inventory programs into Windows. Sales took off again. The Internet was just beginning to break ground and my son created a web site for selling the software.

I sold my computer business in 2000 after many successful years. I have the TRS-80 to thank for the start and for getting me into the computer business.

Derald Freeman