TRS-80

The TRS -80 Model 1 of RadioShack was next to the Apple II and the Commodore PET 2001 to the first home computers were produced in significant numbers as finished copies. He came in 1977 to market and was equipped with a Z80 CPU Zilog, which ran with 1.77 MHz clock frequency. The TRS -80 had good sales success particularly in the United States. The retail price in Germany amounted to DM 3000

First, he was supplied with only 4 KiB RAM ( could be upgraded within the keyboard on 16 KiB). Typical of that time the operating system stored in ROM was in the form of BIOS and integrated BASIC. With the help of an " Expansion Interface " he allowed himself to extend by a further 32 KiB RAM, a floppy disk controller for up to four 5.25 "drives and one serial and one parallel port.

Graphics and equipment

The TRS -80 Model 1 had a " video resolution " of 128 by 48 pixels. This resolution was generated by the character cell of the screen, which were divided into 6 blocks. So in reality it was of special characters 64 * 16 lines text mode, which had to be used intelligently, sa block diagram. As a screen any commercial television could be used for a zuzukaufenden RF modulator, if you put no value on high image quality; originally a monitor was included, which was available with black and white or black and green display.

It was from a Level I Model 1 with 4 KiB ROM and a simplistic BASIC, and a Level II with 12 KiB ROM and BASIC, which already corresponded to the then-popular Microsoft standard (and also licensed from there was ) and by the who extended expansion interface to floppy commands.

One of the cult programs of that time, despite the square graphics the game "Dancing Demon" in which a little cute devil danced on the screen and the mono sound of the tape recorder interface should the user entertained.

In the original equipment a bit was saved from money, the screen memory per byte. Characterized the TRS-80 was not able to represent lowercase. If you wanted to achieve this, you had to install a memory module later, the then put the bit number 6 in each byte of video memory available.

Compact cassette and diskette

Initially, the data were also stored on compact cassette, but very soon also various disk operating systems were added ( DOS). The best known were the TRSDOS of Tandy and very advanced NewDos 80 of apparatus. TRSDOS and NewDos 80 supported first 35 track Single Sided Single Density 87.5 KiB floppy in 5.25 " format to be followed with newer drives and controllers also 40 and 80 track Double Sided / Double Density so that 720 KiB were stored. Such disk was comparable to a modern removable hard disk, since 20 to 30 "major" programs found space.

The NewDos 80 allowed even then the home computer field unusual projects such as the remote control of an acoustic coupler and gray Tandy via standard telephone ( Germany ) via the public telephone network from another computer. The first mailboxes or BBS ' emerged in which users could publish posts in virtual bulletin boards. There was also back in the early 80s catalogs with dozens Office programs from a wide variety of manufacturers such as text, costing, financial accounting, warehouse etc. for the TRS 80, but can be changed from about 1982 after the introduction of the IBM PC with MS- DOS and then div " compatibles " rapidly completed.

More TRS -80 models and replicas

Based on the TRS -80 Model 1, there were also the models II, III and 4 ( in this notation, the first and the fourth model were provided in the catalog with an Arabic numeral ) who had at least been integrated floppy disk drives and due to the price situation and facilities were already among the office computers. Model II was in contrast to all other without the need for changes to software or hardware with CP / M and had 8 "drives, which was also advertised as. Models except Model 1 and the monitor had firmly integrated into the overall housing. The model II was used eg in Bavarian savings banks for credit calculation.

The TRS -80 experienced a replica by a company called EACA, which, in Germany and Western Europe under the name " video genius" ( by Trommeschläger Computer GmbH ), in Australia as "System 80 ", in the U.S. as " PMC 80 " was sold in Hungary as " HT- 1080Z " and in South Africa as " TRZ -80 ". The replica was compatible with virtually 100 % and was only some differences in the hardware control on. In contrast to the TRS -80 Model 1, the video genius was never delivered to a monitor, but it had integrated a video modulator and a tape recorder. There was less successful follow-up models that went far beyond the part about the specifications of Tandy / Radio Shack, but continued to try to maintain compatibility.

Another replica of the TRS -80 Model 1 was sold under the name KomTec in Germany, variously exist private replicas on the basis of modified Z80 single board computers.

The Polish company Mera- Elzab built in the early 1980 computer series Meritum ( first Meritum I and since 1985 Meritum II), which was based on the TRS -80. The difference with the TRS -80 was mainly that in the production made ​​only in the Eastern Bloc components (including U880D - the East German version of the Z80 ) were used. This clone of a TRS -80 was in Poland quickly become very popular and had a decisive influence on the computerization of schools, losing to the Western competitors Atari, Commodore and ZX Spectrum ( Sinclair) later.

Criticism

Questionable that time was the marketing policy of Radio Shack, for example, in their catalog this rather expensive office computer (model II over $ 10,000) were placed adjacent to plush toys with built-in radio. In this way, to Tandy / Radio Shack disqualified to professional buyers. The units were sold at Media Markt next Hifi and electronics in Europe in their own TANDY stores like today. In addition, there were several computer Franchiser and pure Tandy computer stores.

Also questionable was the construction of the power supplies offered for the German market. These were based on the power supplies for the U.S. market and were deficient adapted, which they produced significant amounts of waste heat. Some users run their computers for waste heat reduction and protection of the hardware - through regulating transformers - easily with a mains voltage of 180 V ( approximately 20% below the then mains voltage of 220 V).

Keep one has benefited TANDY (Radio Shack ) that they taunted the late 1970s in Europe a functioning sales of subsidiaries and so also people allowed to purchase without access to the computer scene. Unfortunately, the German sales tax reasons was settled from 1985 again, though most stores still generated high profits.

Community

Even then, users groups banded together intensively, even when there were no inexpensive (or in Germany allowed ) modem or acoustic coupler were available. There was more known users journals called 80 and 80 micro - northwest, which later became the national 80 -US.

In the scene of the TRS- 80 is derided as "Trash 80 " (Eng. " trash 80").