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Tandy topics

For all readers

Ed Juge, Director of Merchandising, Business Computer Products

1500 One Tandy Center, Fort Worth, TX 76102

The January issue of Basic Computing contains an interview with Chuck Tesler. Chuck indicated we might take exception to some of his comments, and I wouldn't want to disappoint him! I can't argue SuperScripsit with him, it was very late! We expected to have it by the time the first advertising appeared, but our choice was to slip it or bring it out with known bugs. I don't think you'll see much more "early advertising" from us.

The gentleman simply isn't well informed on us and our attitudes. His comment that in our viewpoint there are two types of people, us and deadly enemies, just doesn't wash with the more than 1,200 software companies we're working with in our Outside Software Support Program. No, we haven't taken on products that are competitive to our own. That wasn't the purpose of the program. It was set up to fill gaps in our software line. Apple didn't ask us to let them sell the Tandy 2000 either. It hardly means they're "predatory" just because they choose not to sell our products. Come on, Chuck, join the real world!

Yes, we said we might accept some (not just "any") products for private-labeled, in-store sales. So many have been submitted, I'm afraid we're way too far behind in replying. The good news is, as I've indicated before, our software strategy is undergoing quite an overhaul, for several reasons:

1) We can't afford to inventory everything customers want at the store level.

2) There's a practical limit to the number of programs our store personnel can learn to demonstrate, much less support.

3) Ditto our customer service and programming staffs.

4) We need to respond to the evergrowing demand for, and supply of, 52 Basic Computing programs in the marketplace.

5) There's- also a limit to the number of packages we can afford to inventory at the warehouse level.

Our solution will go something like this: Under the Radio Shack label, and available in our stores, expect to find the Word Processing, Spreadsheet, Database Management, Accounting, Language, Game, Home Education, and some other "Productivity" programs. Available on customer-order only (not store stocked), will be Radio Shack branded communications, development, school, and a few vertical market packages among others. For some time now, we've had categories of non-store stocked programs, which aren't fast enough movers to justify shelf space.

What's "Express Order Software?"

Effective before you read this column, we will have initiated a program tentatively called "Express Order Software." It will consist of software stocked in the warehouse only, and available for overnight shipment to any store when a customer orders it. Express Order Software products will not be Radio Shack branded. Instead, they would carry the Micro-Pro, Peachtree, Digital Research, or whatever, label. (I am not promising those lines, just an example). They will not be supported in any way by Radio Shack. If you have a question, there will be a customer service phone number in each package for you to call. It will be that of the author/publisher. Our store and customer service people won't be familiar with the operation of these items. We will be acting as a dealer or sales agent only. For those of you who are familiar with it, Express Order Software will be similar to IBM's "Non-Logo" software program.

Wow, tens of thousands of programs! Right? Wrong! We will probably stock almost anything which has proven itself to be a market leader (top 50 seller list, etc.), if the publisher wants to participate. We'll carry good vertical market software. Each item will be stocked in small quantities until it proves itself, then whatever is needed to keep the pipeline full. And yes, Chuck, Express Order Software finally gives us a viable way to offer competitive products!

There will be a selection process, and offerings will still be rejected. We will publish an Express Order Software program catalog, probably quarterly. We're excited about it, as are the vendors we've discussed it with. As I write this column, we're ironing out the final details of the contract. Submissions should be through Phil Kitchen, Manager of our Outside Software Support Group, 1300 One Tandy Center, Ft. Worth, TX 76102.

Support of Older TRS-80's

This subject has been covered before, but it's been cropping up more often lately, with the introduction of the Tandy 2000. It's probably time to cover it again.

A gentleman recently called several people in Tandy Center, complaining of lack of support for his Model I. He said that we said that we'd support it forever, and we aren't. Well, "forever" is probably an overstatement. Am I prejudiced? Probably, 'cause in my den still sits a 16K, Level II, non-disk Model I. I've refused to sell it, yet I don't use it any more. Since it caused a major change in my career path, I'm sentimentally attached. If it wasn't so all-fired big, I'd probably have it bronzed!

Anyway, we did say we would

Tandy topics continue support for discontinued models as long as there was sufficient demand. Model I owners will attest that we split out their disks from some of the I/III compatible packages, so that in addition to the package, we had to separately order the Model I disks for them. That, among other things, gave us a fair barometer of demand for Model I packages. All of our other indicators tell us that demand has waned to a very low level, even though there are hundreds of thousands of Model I's still in use.

Second, some packages simply won't fit in the 32K available memory, or on the standard Model I disks. For whatever reasons, we don't believe we can 'downsize' the capabilities of an item, just to make it backward-compatible. It isn't fair to the owners of newer models, and would make us highly uncompetitive in the marketplace. As technology lets us do grander things, we must take advantage of those opportunities.

A substantial amount of our software is written by third parties who receive royalties on sales. Many of them choose not to devote their resources to developing versions compatible with anybody's non-current computers. So, backward compatibility is most often a matter of the cost in terms of resources, time, and program capabilities.

As to hardware, that's another matter. Model I owners have asked us to build Expansion Interfaces. The FCC specifically limited the number of them we could build during the year following the emission regulations. Sorry, we can build no more. Other hardware items we tried met with little demand. Am I saying we're through supporting Model I (or III or II, etc.)? By no means. I am explaining the factors which determine the level of support we will offer.

The Elusive CP/M!

Maybe I'm safe in saying CP/M will be available by the time you read this. It has been released for production, for both the Model 4 and the Models 11/12. Model 12 owners can address the full 80K of RAM. Model II will be to 64K. Model 16 conversions will still only address the Z-80 RAM as outlined above.

Things are going well. Model 4P's and Tandy 2000's are in short supply due to parts availability, but the situation should improve soon. Multi-user Scripsit and Profile are in the final stages of testing, and could make it to the warehouse about the time you get this magazine. Most of the Tandy 2000 initial tier of software is available as of this writing. Accounting was delayed by a hiccup in the printer driver, but should be corrected next week. Word Processing (MultiMate) is in test, looking good, waiting the remaining parts of documentation to come in from the vendor. It is targeted for release February 15th. Some very exciting software is in the queue for the 2000! Stay tuned, see you next month. (Boy, it's nice to be able to transmit my column to Basic Computing via EMAIL! Federal Express, eat your heart out!)

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BASIC bits

Model 4 tips and more on running in Model III mode

Model 111/4

Thomas L. Quindry

I'm very new to computing. In the article, "Exploring VisiCalc" (November, 1983 issue, page 59), Timothy Bowman refers to a Model 4 running in the Model III mode. How can this be done? Is it documented in either the owner's manual or the technical manual, or is it the product of some superior programmer's software program which I do not have or know about? Also, how can I POKE graphic characters to the screen in BASIC? The manual "Getting Started With TRS-80 BASIC" for Models I and III gives the information for those computers, but it won't work on the Model IV.

The Model 4 has a dual operating system to allow compatibility with older models. Surprisingly, the Model 4 manual does not convey this information properly. Someone new to the Radio Shack computer line would have to stumble on this by accident as a friend of mine did. One mode of operation is as a Model III (including cassette operation). On power-up, or when rebooting (pushing the reset button), you can use either a Model III or Model 4 Disk Operating System (DOS). TRSDOS 6.0 comes with the Model 4 as the Model 4 DOS. Any of the Model III DOSs on the market today will automatically cause your Model 4 to run in the Model III mode.

To use the Model III mode, buy a Model III DOS and boot up the disk. 54 Basic Computing

The least expensive is Radio Shack's TRSDOS 1.3 for $14.95 and the Model III Disk Systems Owner's Manual for $6.95. Since not much in the way of software yet exists for the Model 4, it wouldn't be a bad idea to have the Model III DOS anyway. You can also hold down the break key while hitting the reset button and get into Model III Level II BASIC. This does not support disk but you can load programs by cassette.

You cannot POKE to the video screen in the Model 4 mode. The Model 4 video can only be written to by what is called Service Calls. The BASIC PRINT command does this. You should consult your technical manual to determine how to do this in machine language. The reason POKE does not work is because the video memory is bank-switched. There is no place for you to POKE to since video memory is never accessible when you want to POKE.

Now that we have a Model I, Model III and Model 4 that are upward-compatible, those of us who write programs to run on any of the machines need a way to know which machine is in use and what the clock speed is.

I understand POKE 16912, PEEK (16912)OR64 will make the Model 4 run at 4Mhz in the Model III mode, but it seems to make TIME$ run at twice speed. Is there a way to make the Model 4 run at 4Mhz in the Model III mode and still have correct real time clock operation?

Finally, is there a way to access the internal sound from the Model III mode? It would be nice if there were an easy way to modify the many Model III programs that output sound through the cassette port to run on the Model 4 without requiring an external audio amplifier.

I'll answer the questions in reverse order. To get your answers, I called on users of our computer club bulletin board, the TCUG resource network. Amir Naini of Huntington, MD responded with an answer to the sound output question. Amir says that you just change the output port used in your cassette port sound generation program from the cassette port 255 to port 144. It is his opinion that the inexpensive external speaker that Radio Shack sells for $11.95 (cat. no. 277-1008) sounds better than the speaker installed in the Model 4 so you are better off not changing the port address.

Your solution to Model III mode clock speed-up is only partly correct. John Harrell of Washington, DC gives the following:

10 X=PEEK(16912) 20 X=X OR 64 30 POKE 16912.X 40 OUT 236,X

The output to the port is necessary to correct disk I/O operations. (Port

236 will eventually get changed to the correct value by normal computer operations by things such as CLS but you might as well set it straight at the outset.) John also gives the following to slow back to the Model III clock speed: 10 X=PEEK(16912) 20 X=X AND 191 30 POKE 16912,X 40 OUT 236,X

Though it shouldn't be, I must caution you that it has been reported that there still may be some disk I/O problems (see last issue's "Notes, etc." column —Ed.). So, it may be a good idea to use the slow-down procedure given just before accessing the disk. You can speed it up again just after accessing.

The essence of the above two routines is that bit 6 of the address and port given is set or reset depending on clock speed desired.

Now, the hard part. My thanks to Jerry Weisskohl of Falls Church, VA for letting me try out his Model 4 to test the following. Running the

Model III mode with the clock speedup does, in fact, accelerate the values placed in the binary time-date addresses at 16919 through 16924 decimal. This is because outputting the speed-up bit to the port causes twice as many interrupts to be made. This was done by design, not by mistake, for Model 4 operation. The clock-pulse counter has to be made to double the count for each second. The code starting at 3529H, among other things, decrements the clock-pulse counter to zero, increments the clock buffer, and resets the pulse counter with a command to LD (HL),01EH starting at address 355CH.

In the Model III mode of the Model 4 with the clock speeded up, this value of 01EH must be increased to twice the value, or 03CH, to cause the clock to count correctly. Since this code is in ROM, I have written a patch code routine. The routine I've written changes the address given at 4047H to send control to my routine, repeats all code from the address 3529H to 355CH, and gives a different value than that given in 355DH to set the maximum number of clock pulses needed to increment the clock by one second. It then jumps back to the ROM routine starting at 355EH.

One word of caution. Your natural impulse will be to name this routine, CLOCK/CMD. Don't doit. If you try to access the program by entering the word CLOCK, you will only turn on the clock and date display in the upper right-hand corner of your screen. Better yet, name it CLOCKSPD/CMD.

My June, 1983 column gives a table which will tell you which computer you are on and whether it is cassette- or disk-based. It refers to the Model I and Model III. (Note the correction given in September, 1983.) These values hold for the Model III mode of the Model 4 as best I can determine. Since the Model 4 BASIC is different, as well as the screen size, it would probably be best to write a different program for the

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