• Tag Archives TRS80

  • TRS-80 Model III

    Posted on by Azrael Comment

    It seems like every computer maker was using some celebrity to sell there machines in the early 1980s. Commodore had the right idea with William Shatner for the VIC-20. Who better to sell a computer than a sci-fi star? Radio Shack did well also with the famed Sci-Fi and science writer Isaac Asimov. Of course, then there was Texas Instruments with Bill Cosby for the TI-99/4A…

    I’m not sure that “You Won’t Find a Broader Line of Microcomputers Than Radio Shack’s TRS-80” is the absolute best endorsement they could have come up with but what they were getting at is that there were a number of TRS-80 models that excelled for different purposes. Most computer makers had basically one model or sometimes two. Apple only really had the Apple II at this point, Commodore the VIC-20 and PET, Texas Instruments the TI-99/4A, etc. Tandy/Radio Shack at this point (circa 1980 or so) had the Model II and Model III (unrelated really), the color computer and a couple of portable models. Interetingly they seem to be advertising the Color Computer as a games machine and in the very early 1980s it was still a selling point to have off-the-shelf software available as opposed to having to write your own. Though the Model III is not mentioned by name in this ad, it is the one that Isaac Asimov is using in the picture.

    In this second ad with Asimov, he is featuring the TRS-80 Model III and in particular it’s ability as a word processing system. It seem that SuperSCRIPSIT must have been the best thing since sliced bread.

    The TRS-80 Model III was probably the most common TRS-80 model at this particular time because of its relative popularity in the education market. Illogically, the Model III was the successor to the original TRS-80 while the Model II was a completely different machine (good thing they didn’t use Leonard Nimoy for this ad). The Model III was completely redesigned into an all-in-one design and had a number of enhancements while maintaining compatibility (at least 80% anyway) with the Model I.

    The Model III was released in July 1980. In addition to being an all-in-one unit, it had a better keyboard, could now do lowercase letters and had a faster processor (a 2.03 MHz Z-80 vs. the 1.77 MHz version in the original) and faster and more reliable disk and cassette interfaces. The lowest end version still only had 4KB of memory but it was expandable up to 48KB. Two floppy drives could be added to the case (typically single-sided, double-density) though a power supply upgrade and system memory of at least 32KB was necessary to do so. TR-DOS 1.3 was the default OS but other 3rd party DOS versions were also available, the most common being LDOS.

    My computer programming class when I was a freshman in high school used TRS-80 Model IIIs and 4s. This was in 1989-90 when they were already long out of date (though the Model 4D was still being sold at this time).

    “Hidden in the trash” was a reference to the ancient TRS-80 line of computers made by Tandy and Radio Shack in the ‘70s and ’80s. Computer users of that era had given the TRS-80 the derogatory nickname of “Trash 80.”

    —

    -Ernest Cline, Ready Player One

    http://darth-azrael.tumblr.com/post/163489632349/anoraksalmanac-hidden-in-the-trash-was-a





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  • Zork (TRS-80)

    Posted on by Azrael Comment

    Zork, TRS-80.

    http://darth-azrael.tumblr.com/post/163484334369/vgjunk-zork-trs-80

    Zork has a lineage the goes back pretty much as far as computer games go and it is one of the most prolific games in existence in terms of the number of platforms it was available for. The TRS-80 version was the very first commercial version available in 1980. But I’m getting ahead of things…

    Zork is a text adventure game or Interactive Fiction as some like to call it. Essentially, it is an adventure game that is played entirely in text. Descriptions of events, the environment and objects in the environment are given as text and commands are issued as text. This was a briefly popular genre of games from when computers were more limited. The Zork series is perhaps the most popular though there were a number of other such games by Infocom and others throughout the early to mid 1980s and beyond.

    Zork was inspired by the simpler Colossal Cave Adventure which was written in 1975 in FORTRAN to run on a DEC PDP-10. Like Colossal Cave, Zork (or Dungeon as it was originally called) was written to run on a PDP-10 but it was written using MDL (a LISP derivative). An ~512K version was runnable by 1977 and it was ported to TENEX/TOPS-20 which was an operating system than ran on various DEC mainframes. At this point, the game started making its way around the Arpanet (Internet predecessor) though enhancements and bug fixes would continue to be made until 1979. At this point the game was about 1 MB which was massive for the time. Zork was also ported to FORTRAN with an initial release in January 1978 which led to it becoming available on more platforms, such as the PDP-11 and DEC VAXes.

    Finally, the original developers decided to form Infocom and make Zork one of their first products. Since home computers didn’t generally have FORTRAN compilers at this time, they decided to reimplement the game using a language they invented (Zork Implementation Language) and build interpreters for each machine (interpreted languages like Python work in an analogous manner). The first interpreter (ZIP for Z-machine Interpreter) was completed in 1979. After this, much of the game had to be cut out because a megabyte was way too big for home computers at the time. The first Zork release for home computers contained about half of the original locations. The remaining locations would be used for Zork II and III. Initially, Infocom made a deal with Personal Software, the same company responsible for VisiCalc, to distribute Zork and the TRS-80 version was the first version completed in 1980. An Apple II version followed in 1981 and when Zork II was released, Infocom took over distribution. When Zork III was released in the Fall of 1982, interpreters were also released for the Commodore 64, Commodore Plus/4, Atari 8-bit, CP/M, and IBM PC. Further platforms would follow and the rest is history.

    The original TRS-80 version was distributed in a clear plastic bag containing just the disk and a 36 page book (pictured above). This version is quite rare today. After Zork II came out and the original was re-released as Zork I, it came in the typical folio packaging Infocom was known for. This version required the TRS-80 Model III with 32K but otherwise I’m not sure what the difference between the games was.





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  • TRS-80 Model I

    Posted on by Azrael Comment

    Tandy Radio Shack – 80 Home computer

    TRS-80

    http://darth-azrael.tumblr.com/post/163450055879/retrobear-tandy-radio-shack-80-home-computer

    The TRS-80 Model I (originally just called the TRS-80) was Radio Shack’s first computer. Introduced in 1977, it was one of the earliest home computers. It competed with the Commodore PET and Apple II as well as the Atari 400/800 all of which were introduced around the same time frame. The TRS-80 was based on the Zilog Z80 CPU and originally shipped with just 4K of RAM though it was expandable to 48K. Most other home computers at that time were based on the 6502 processor.

    The TRS-80 enjoyed a brief period of domination as it was the best selling computer, outselling Commodore and Apple, through 1981. It also had the largest selection of software during that time period. In 1980 it was selling at a rate triple that of Apple who was in second place. After 1981, the TRS-80’s dominance faded as cheaper and graphically more sophisticated computers like the VIC-20 arrived and Apple started gaining a greater foothold. The TRS-80 had a disadvantage in that it did not support color graphics or much in the way of graphics at all beyond basic text. Oddly, at a time when most computers had 40-column displays or perhaps 80-column displays with an upgrade, the TRS-80 had a 64-column display. In addition to TR-DOS, the TRS-80 could also run CP/M but only with modifications.

    A cassette tape drive was included with the TRS-80 to save an load programs. However, it was slow and unreliable. It was difficult to adjust the volume settings correctly for saving and it was often a process of trial and error. In order to add any other hardware, including a disk drive, real-time clock, serial port or even a printer, an Expansion Interface box had to be purchased along with the appropriate expansion card. The Expansion Interface (E/I) box is the box the monitor is sitting on in the picture above. The Expansion Interface box included a floppy disk controller. A single density, 85Kb floppy drive became available about six months after the TRS-80 was introduced. This was also initially unreliable, largely due to buggy TRS-80 ROM code but could be compensated for. More capable third party drives eventually became available as did a hard drive but it was extremely expensive at nearly $2500 for 5MB. A second 5MB drive could be added to the hard drive chassis for an additional $2000. The hard drive chassis could hold up to four drives for a whopping 20 MB at a bargain price of $8500.

    Despite Radio Shack’s mostly low quality software, there were a large number of third party titles available that were much better. For a long time, Radio Shack refused to sell any software it did not develop and this probably contributed the the TRS-80’s fall from domination over the years. Despite note having much in the way of graphical capabilities, there were a number of games (including Zork!) available in addition to productivity and other types of software.

    The TRS-80 was succeeded in 1980 by the Model III (the Model II was a completely different non-compatible business oriented machine) and in 1984 by the Model 4. There was also a luggable version (4P) and finally in 1985 the 4D was introduced. This was the last TRS-80 computer and was available all the way through 1991.





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