Classic Computer Magazine Archive CREATIVE COMPUTING VOL. 9, NO. 8 / AUGUST 1983 / PAGE 240

...TRS-80 strings... (column) Stephen B. Gray.

TRS-80 Strings

As our Radio Shack balloon rises past the 54,000-foot altitude level, we pause to check out a disk catalog program from Sams, the Color Computer Quick Reference Guide, six Color Computer programs from Computerware, and another short screen saver program.

AOS Back to INpolis, Renamed Sams

The first software offered by Howard W. Sams & Co., the technical book publisher, was marketed under the Advanced Operating Systems label (Dec. 1981, p. 322).

AOS was moved from Indianapolis to Michigan City, IN, because the head of the division wanted to live there. He left after a year and a half, AOS moved back to Indianapolis, and the Sams name replaced the AOS name as of December, 1982.

The Sams catalog now includes software, in addition to the type of books that made the company famous. There are programs for the TRS-80, Apple, IBM PC, Commodore and Timex/ Sinclair personal computers in areas such as business, word processing, games, electronic engineering, and communications.

We'll be looking at several Sams software products, starting with a disk catalog program in this issue.

Disk Catalog

After you have filled your first disk and have to start a second one, you begin to have trouble keeping track of what program or file is on which disk.

One solution is to keep all programs or files of a particular type on one disk. Keep all the Basic programs on one disk, Scripsit files on another, etc. But once you have filled the Basic disk or the Scripsit disk, the problems begin again.

Incidentally, one way of keeping track of what is recorded is to use extensions. When someone sends me a letter containing a program for the Short Program section of this column, I first enter the program in Basic with a/BAS extension and a number to indicate the sequence of letters, such as LET037/BAS. Then I type the letter itself in Scripsit, using the same letter number but a different extension: LET037/SCR, and call the Basic program from Scripsit.

Thus, I know the program part of the Short Program item is correct, because I entered it in Basic and ran it before storing it. Using extensions, I keep the letter text separate from the Basic program, for separate printouts later: the letter with a daisywheel printer; the program with a dot-matrix printer, in case the editor would like to use a more authentic-looking listing.

Master Directory III

However, even with extensions, there comes a time when the only way to go is with a master disk directory program (also called a disk catalog program). A very good one is Master Directory III, for a TRS-80 Model III with 16K of memory and at least one disk drive, $39.95 at computer stores or, with a $2 charge per order for handling, from Howard W. Sams & Co., Inc., 4300 West 62 St., Indianapolis, IN 46206.

Using this program couldn't be simpler. Just put the Sams disk in drive 0 and press the reset button. You get a menu with nine choices. At the beginning, you have only one: read the directories from your disks.

After you have assigned each disk a unique number from 0 to 999, and put the number on each disk label, just put each disk in drive 1 (or if you have only one drive, switch the Sams disk and your disks back and forth), give the number of the disk and press ENTER. Master Directory III is compatible with almost any DOS, so there is no problem if a disk was made with TRSDOS or DOSPLUS or whatever. Do the same thing with all your disks, and within minutes you have created a master directory that allows you to search for a program or file in several different ways. The system provides seven different reports, which can be displayed or printed out.

You can also catalog an 80-track disk, and read invisible files into your directory.

Searching the Directory

You can ask to see the directory for a disk by entering its number after asking for item 1 on the menu, Disk Directory. If you have any doubt about a particular disk having been cataloged, ask for the Master Disk Listing, which lists all disks in the master directory by name, number, number of free granules, date cataloged, etc.

If space is tight, you can Search For Free Space by specifying how much you need. You can delete the directory for any particular disk, which is necessary, for example, if you want to read in an updated directory.

The most useful command of the system is File Name Search. Just ask for item 6 on the menu and type in the name of the file you want. If you want to see a group of file locations with similar names, use a ? as part of the file name, which means that that letter doesn't matter. If you fill the rest of the filename with? then you'll get a listing of all files with that name plus all longer names that begin with that name.

If you have forgotten the name of a program or file, or just want to look through the names of everything you have on disk, ask for the Master List Filing, which provides a full directory of all disk programs, in alphabetical order.

If you know the name of the disk you want (and have given each disk a different name), choose File Listing By Category. To get a report for a requested extension, ask for item 9, File Listing By Extension, which will display and/or print all programs of files using that extension, whether it is SCR or BAS or CMD or PAS or thatever (Figure 1).

That's just about all there is to it. There is no simpler way of keeping track of all your disk files and programs than with the Sams Master Directory III.

Quick Reference Guide

A handy new publication, Radio Shack's new $4.95 "TRS-80 Color Computer Quick Reference Guide' is a 71-pager to keep near your computer for a fast lookup.

The guide has just about everything you need for quick reference, including everything that is on those foldout cards that come with the manuals, plus a lot more.

You get nine pages of all the statements, color-coded to indicate which are only for Extended Color Basic, and which are only for Disk Extended Color Basic. Then come lists of functions, ROM subroutines, control keys, color codes, ASCII codes, editor commands, ZBUG commands, 6809 instructions, editor/assembler error messages, memory map, Basic error messages, technical specifications, and many more.

This 4 by 8 guide is wire-bound to stay open beside your Color Computer. Once you have gone through the manuals, this is what you need for quick reference.

Six Programs from Computerware

Four games, a money manager, and a tutorial for the Color Computer were sent by Computerware (Box 668, 4403 Manchester Ave., Suite 102, Encinitas, CA 92024). The four games are all quite exciting, and well worth checking out. The money manager is a sophisticated checkbook balancer, but the tutorial is too expensive for what it contains.

Bloc Head

The game of Bloc Head ($26.95 cassette, $29.95 disk) presents a grid of 27 cubes. You are the Bloc Head, and the object is to change the color of the top of each cube to the color indicated in a corner of the screen. All you have to do is use the joystick to move from one cube to another, and the color changes as you land on each.

There are problems, of course. Several monsters will try to jump on you, which could take one of your four lives. If you aim away from the cube grid, you might fall off the edge. But if you can change all the cubes to the new color, you get bonus points and start all over again.

There are "easy' and "tuff' levels in this intriguing game that will have you jumping all over the screen to change cube colors without getting wiped out.

Nerble Force

You are one of the last human survivors on Nerble, and your goal, as pilot of the last human spaceship, is to defend the planet against the Nerble Force. You control your ship (which has four lives) with the joystick, and fire phasers with the button.

Six types of Nerbloids make life difficult, and must be shot down or avoided. One or two humans can play, at four levels of difficulty, and the game can be frozen (for later unfreezing) or reset at any time.

The action is exciting, as you pilot your ship left and right, up and down, firing away at targets, avoiding mines, always watching the long-range scanner at the bottom of the screen that tells you where the aliens are.

A nice touch: if there are five or more aliens on the screen when you die, your ship supply will not decrease. This lets you "kamikaze' when surrounded, for $24.95 on cassette, $29.95 on disk.

Gran Prix

The longer you stay on the track without crashing, and the faster you drive in this 32K game, the more points you get. Moving the joystick forward or back controls your speed; moving it left and right controls your steering in the high-powered racer.

Just to keep you on your toes, you'll sometimes have to drive at night, or on snow covered roads. You have 100 seconds to rack up points, but if you can get over 2000 points, you earn extended play, in this fast-moving game you will play over and over. The program keeps track of the top ten scores, and is $21.95 on cassette, $26.95 on disk.

Moon Hopper

This 32K game ($24.95 cassette, $29.95 disk) uses an advanced type of moon buggy, with a "secret feature' that allows it to jump over obstacles instead of going around them. On Space Patrol maneuvers, you are attacked by Traglons, so you try to hold them off with phasers while racing to the moonbase for reinforcements. Can you make it before the Traglon saucers blow you to bits?

Choose one of five levels of play, and use the joystick to control speed and direction, the button to fire the phasers. You jump the hopper by moving the joystick upwards for a moment, to leap over craters. Boulders can be jumped or shot.

A long-range scanner at screen bottom tells you how close you are to the base, and you get points for vaporizing aliens and boulders, in this heart-stopping race for life on a dead moon.

Home Money Manager

This is a $29.95 disk based, menu driven, personal checkbook system that "tracks data by Date, Paid To, Check Number, Account Number, Amount of Check, and Current Balance,' according to the brief eight-page manual.

The program shows exactly how much you spent on what, and where your income came from. Up to 480 transactions can be recorded.

To use the program, you create a new checkbook file, entering your current balance and information on checks written, assigning an account code to each check. After the data for each check is entered, the new current balance is displayed. Deposits are entered in the same manner.

You can easily make corrections, view files, change account names, and update the balance. Four reports can be printed out, if you have an 80-column printer: transactions (deposits and expenses), deposits, expenses, and accounts (year-to-date).

A demonstration file is provided; "It is recommended that you practice with this file so you can make any mistakes on it instead of your own data,' the manual says.

This porgram is fairly sophisticated, and can be recommended to those who find the ordinary check registers provided with checkbooks to be too simple for their needs. (Although the manual says this is a disk based program, Computerware quoted me a $19.95 price for cassette.)

Intro to Data Communications

This five-part Extended Basic program is said by the five-page manual to be designed "to teach a beginner the basic ideas and terminology to allow him (her) to use a data communications device easily.'

The first four parts teach very elementary theory about modems, RS-232, synchronous transmission, baud rate, etc. A dozen illustrations make good use of color graphics. The fifth part is a multiple choice test with ten questions.

This program is $17.95 on cassette, $22.95 on disk. For $12.95, you can buy "TRS-80 Data Communications Systems,' by Frank J. Derfler Jr. (Spectrum Books, Prentice-Hall Inc.) which, although disappointingly flawed, gives you a great deal more information, is much easier to read than a Color Computer screen, and has three dozen illustrations, and two dozen charts.

Short Program #41: Screen Saver III

From Valley Stream, NY, Matt Fitzgibbon wrote last year, "Lately I've seen, in computer magazines, many programs for saving the contents of the TRS-80 screen to string or numerical arrays.' One of these is Short Program #31 (July 1982, p. 222).

"This program shows one strong fault of screen-save programs written in Basic: they are generally very s-l-o-w! At least they used to be slow. I have been using computers since my freshman year in high school (about three years) and some time ago I wrote a program (entirely in Basic) which takes about one second to store the program.

"I'm sure that at one time or another, most TRS-80 owners have seen programs which use VARPTR to look at the variable pointer of a string. I reasoned that this function could also be used to change the pointer of the string and fool the computer into thinking that the video memory is nothing more than several string variables.

"The program in Listing 1 illustrates this technique. The screen is completely saved (except for the last four bytes) in SC$, from which it is printed back onto the screen. The part of the program that does the actual saving runs from line 70 to line 150.

"If anyone wants to use this as a subroutine in a marketed program, I ask nothing more than a simple REM.'

"Lines 20-60 create a four-way kaleidoscopic graphics image; lines 70-150 save it; lines 160-170 reprint it on the screen.'

Matt's program includes these REMs: "Line 10 puts some text on the screen; lines 20-60 put some graphics there too. In line 70, A$ will point to 255 consecutive bytes of video memory, and line 80 finds the pointer to the location of A$. In line 100, SL is the pointer to which 255-byte block of video is to be read; line 110 sets up bytes so we can make A$ point to location SL. In line 130, A$ is now pointing to the video. Line 140 saves this portion of the screen in array SC$. Line 160 clears the screen and reprints it from SC$.'

Matt added a P.S., "Because this "screen-save' stores graphics and is extremely fast, it can be used in the multitude of "Etch-A-Sketch' programs. Screens can be saved to disk by simply saving the strings, SC$ (0)-SC$ (3).'

Table: Figure 1. This Master Directory III report shows programs and files written in Basic and named with the /BAS extension.

Table: Listing 1.