Tandy's new IBM-compatible held surprises for Stuart Cooke

Tandy's latest micro is something of a turn-up for the books. This US company has consistently produced non-standard machines, but now it is supporting MSDOS, which is rapidly becoming the industry standard for 16-bit computers.

At first sight, the TRS-80 Model 2000 reveals nothing out of the ordinary and it would appear this US giant has simply jumped onto the bandwagon of IBM-compatible machines and is hoping to break into a new market area. However, a closer look at the machine uncovers some interesting features.

For example, the processor is an Intel 80186, which Tandy claims is 'a next generation true 16-bit CPU'. So, the machine runs faster than most of its competitors. Tandy also provides disk drives with a 720K byte capacity, much greater than the standard drives supplied with other machines.

Now that this US company has decided to follow the MSDOS trail it has done it in style by producing a micro which offers more than its IBM-able competitors, thus moving into the PC market - even if it's a little later than most other cloning companies.

The TRS-80 Model 2000 has the same boring looks that are becoming a standard for desk-top business machines. You are supplied with a 'box of tricks' containing the two disk drives and all the processor and expansion cards. The monitor sits on top of the main box and the keyboard plugs in from the front with a coiled lead.

Unfortunately, the whole machine is made from a white plastic and it was only a matter of hours before my finger prints started to appear on the casing giving little hope for its appearance after a short time in a smoky office.

Tandy supplies four manuals with the 2000. Two are large folders, one describing the MSDOS operating system and how to use it, the other the Basic reference manual. The other two pieces of supplied reading are an MSDOS and Basic reference card and an introduction to the 2000.

The latter is aimed at the complete novice. Lots of diagrams show how and where to connect things, and it even takes you through how to turn the machine on and off, so little is missed out. Both the MSDOS and Basic manuals are clear and easy to follow, and a complete beginner to computing should be able to format disks and load programs within minutes of sitting in front of the machine.

Almost immediately you will see exactly why Tandy chose the 80186 for the CPU. Programs run much faster than the same software would on a comparable machine. A local Tandy store supplied a copy of Multiplan to judge the speed at which this machine could operate.

Plugging the keyboard into the front of the machine is done with a DIN plug and socket. What is really unfortunate is that the socket this plug fits into is hidden away under a lip on the front of the machine. It proved impossible to plug in or remove the keyboard without either getting some assistance or risking a disaster.

The keyboard is of the normal 'low profile' type, has 90 keys including 12 function keys and a ten-key numeric keypad. A couple of retractable legs on the base mean the keyboard can be tilted.

It has a good feel, and a touch typist should find it comfortable to use. The only gripe is that the spacebar is small and has a tendency to rattle when pressed.

A colour monitor and colour graphics board were provided with the review machine, and the display gave a very clear and sharp picture which was easy to read. The demo disk gave a good impression of the potential of the graphics; graph plotting was quick and the Basic FILL command was among the fastest and smoothest I have come across. Graphics resolution is 640 x 400 for both colour and monochrome displays with eight colours if you have a colour board installed.

Compare this to the four colours and 320 x 200 colour, 640 x 200 monochrome resolution on the IBM and you can see that for graphics, the Tandy machine would be a good choice.

The machine's speed makes smooth and fast animated displays possible. In fact, the demo program flashes a number of points on the border of one of the displays very quickly, and this is performed in Basic.

Each of the drives provided on the Model 2000 have a 720K capacity. One of the demo programs displays how the total capacity of these two drives is equivalent to nine of the drives on the standard IBM. Even with this large capacity no problems were encountered while using them.

It is extremely easy to expand the machine. All that's involved is to slide the expansion board into one of the expansion slots on the rear of the machine. Expansion boards exist for RAM expansion, a real time clock and a Digi Mouse controller board.

Since the Tandy 2000 uses the MSDOS operating system there is a reasonably big market of software available. Not all software can be loaded into the machine and run straight away, even though it is possible to read IBM format disks. Tandy is in the process of converting many popular MSDOS packages and can already supply compilers, word processors and spreadsheets.

Basic is supplied with the machine, the dialect of which bears an uncanny resemblance to Microsoft's Extended Colour Basic. If you have ever had the chance to use a Tandy colour computer, or an IBM model, you should have no problems.

As with all the packages you can get with the machine, the Basic is very fast. I examined the demo disk with the machine, and I found it was all produced from Basic.

The Tandy Model 2000 has some attractive features compared to machines with a similar price tag. If you want to play around with graphics or require a machine that is fast, take a look. If you only require a machine that runs MSDOS, you will probably find this machine more expensive than its alternatives.

Intel 80186

Examples of IBM PC packages which will run on the Tandy Model 2000 are:

Even though the Tandy 2000 uses the MSDOS operating system it is not possible to run all the software that is available for other MSDOS or IBM-compatible machines.

There are three categories for MSDOS software:

Category 1

To run software which falls into this category, the user simply boots up the MSDOS operating system, removes the system disk and runs the software as described in the manual.

Category 2

Software that falls into this category must be converted for use on the Tandy 2000 by the user. Tandy supplies information sheets to explain how to do this.

Category 3

Any programs that fall into this category will not run at all. However, Tandy is having most of the popular pieces of software rewritten to run on the 2000.

The Tandy Model 2000 runs the 80186 processor, an upgraded and more compact version of the 8086. This advanced processor gives the 2000 almost twice the processing speed of an IBM PC in some applications, although this is mainly due to the Tandy clock frequency of 8MHz as compared to the PC's 5MHz.

The 80186 also has the advantage that, apart from being more compact, it is software-compatible with the 8080, the 8085, the 8086 and the 8088.

This means that software originally written for the 8080, such as Wordstar, and software written for the 8088 such as the suite of Perfect Software or Lotus 1-2-3, can easily be converted to run on the Tandy Model 2000, and any modifications will only be for input/output protocols and peripheral devices.

Internally, the 80186 is basically a whole computer system on a single chip. The CPU is an enhanced version of the 8086 with an improved instruction set, to make assembly language programming a little easier, and changes in the internal architecture to make the instructions execute a little faster.

Also included on the chip are devices that would normally be separate chips, such as clock generators, DMA controllers, timers, and the chip select logic. This means that instead of the usual 40-pin or even 60-pin chip, the 80186 uses a 68-pin package to accommodoate all of the input/output that is necessary to run a system of this size.

The problem with the 80186 is mainly due to its popularity because of the above features. It is made only by Intel at the moment and, although it is expanding production facilities and talks are going on with Advanced Micro Devices about second sourcing them, the chips are still in fairly short supply. Because of this, it is surprising that Tandy has launched its Model 2000 in the UK so early. This could very easily lead to shortages somewhere along the line which would hold up production and cause delays in deliveries.

But, by the looks of things and, unless something even more amazing comes along, the 80186 is a very comprehensive piece of hardware and will probably do extremely well.

Kenn Garroch