This was my favorite book for learning to program in tiny 4K BASIC on my beloved TRS-80 Model I Micro Computer. I learned by doing. In fact, I developed considerable proficiency as a programmer on my TRS-80. Please, don't call it a "Trash-80." Neither I nor the members of my TRS-80 Users Group ever called it by this pejorative name.

My computer came with a Z80 CPU, 4KB RAM, 4KB ROM containing Level 1 BASIC, a keyboard which housed the motherboard, a black-and-white video display (which was really an RCA B/W television set without the tuner), and a tape cassette, all for only $600.

Level 1 BASIC was very limited. It was single precision only. It was based on Li-Chen Wang's Tiny BASIC. There were 26 integer variables available, A through Z, one single dimension integer array with 876 array locations A(X), and two string variables, A$ and B$, capable of storing 16 bytes each. DATA lines stored the data for a program.

Within a year, I was able to upgrade the ROM in my Model I TRS-80 to 12KB Level 2 BASIC. I was also able to upgrade the RAM from 4KB to 16KB. Level 2 BASIC and 16K of RAM quickly became the standard configuration for the Model I.

My favorite features of Level I BASIC, the ones I missed the most when I upgraded to Level II BASIC, were its error messages: "WHAT?" for syntax errors, "HOW?" for arithmetic errors, such as, division by zero, and "SORRY" for out of memory errors.

The Level I BASIC manual by David Lien was written both as a tutorial and as a reference manual. Lien handled both tasks superbly. This manual belongs in the Software Hall of Fame for its great writing, humorous graphics, and neat programs.

The first part of the manual, Chapters 1-26, taught Level I BASIC. There were helpful exercises at the end of chapters 3-25. The second part of the manual provided sample answers to the programming exercises. The third part of the manual consisted of user's programs written in Level 1 BASIC: Test Grader, Slowpoke, 12-Hour Clock, Checksum for Business, Design Program for Cubical Quad Antenna, Speed Reading, The Wheel of Fortune, Dow-Jones Industrial Average Forecaster, On a Snowy Evening by Robert Frost, Termites, Sorry by Parker Brothers, Automatic Ticket Number Drawer, Craps, Fire When Ready Gridley, House Security, and Loan Amortization.

I especially appreciated the appendix of subroutines that overcame many of the limitations of Level 1 BASIC, such as, Square Root, Exponentiation, Logarithms (Natural and Common), Exponential, Tangent, Cosine, Sine, ArcCosine, ArcSine, ArcTangent, and Sign.

The final appendix in the manual consisted of a utility program to put the TRS-80 through its paces in a three-stage test: Function, RAM, and Display. On my TRS-80 with 16KB of RAM, the Function test took about 3 seconds to run, the RAM test took about 12 minutes to run, and the Display test took no measurable time to draw a test pattern on the screen. ( )