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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.





    Computer Arcana Retro Games TRS-80 📎and tagged

  • 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.





    Computer Arcana TRS-80 📎and tagged

  • TRS-80 Color Computer (1981)

    Posted on by Azrael Comment

    TRS-80 color computer, 1981

    http://darth-azrael.tumblr.com/post/163495719735/gameraboy-trs-80-color-computer-1981

    Before modern CPUs and graphics cards, Radio Shack probably had the most confusing computer related names. Everything early on was a TRS-80 regardless of what it was compatible with. They started with just the TRS-80 Model I. This was compatible with the later TRS-80 Model III and TRS-80 Model IV but not the TRS-80 Model II or the TRS-80 Color Computer. Then there were a variety of other TRS-80 models not related to any of these.

    The Color Computer eventually dropped the TRS-80 designation and computers in that line became to be colloquially known as the CoCo, CoCo 2 and CoCo 3. Here we have an ad for the original TRS-80 Color Computer from way back in 1981. Radio Shack had a surprise hit with their TRS-80 Model I but it couldn’t do color like the Atari, VIC-20 and Apple II so they introduced the Color Computer. At this point, the original TRS-80 line became marketed more as small business machines and the Color Computer as a home machine.

    The Color Computer’s main competition in the home market was probably the VIC-20. They were both introduced around the same time and were relatively inexpensive compared to most other computers on the market at the time. Despite the VIC-20’s less capable CPU, it’s cheaper price, slightly more RAM, more advanced video hardware and Commodore’s decision to put games on cartridges, the VIC-20 beat out the Color Computer in the marketplace. The Color Computer had cartridges too (Program Paks) but third party support was much weaker.

    Having said that, the Color Computer was pretty advanced for its time, particularly in regards to the CPU. Most computers of the time were based on either the Z80 or the 6502 which were both 8-bit CPUs. The Color Computer used a Motorola 6809E processor. This was still an 8-bit processor but had some 16-bit features. It was also used in the Vectrex and some early arcade games such as Defender, Robotron: 2084, Joust and Gyruss. However, despite the advanced processor, the lack of dedicated specialized graphics and sound hardware made the CoCo less capable when it came to games which were a big sales driver for early home computers. The chiclet keyboard probably didn’t help.

    The CoCo originally shipped with 4K of RAM (though systems with 16K and 32K were available above the $399 base price point) and was designed to work with a color television. It was also designed to load and store programs on cassette though a disk drive was available later.

    As the above ad from 1981 shows, a version of the CoCo with Extended BASIC was offered about a year after the CoCo was introduced. BASIC was in ROM chips on the motherboard so it was not just a matter of loading some software. A CoCo with 16K of RAM (the minimum required for BASIC) and Extended BASIC could be had for $599. Alternatively, you could upgrade your existing Color Computer to Extended BASIC for $99 plus installation assuming you already had at least 16K of RAM. Extended BASIC offered additional commands, mostly related to color, sound and graphics that were not available in standard Microsoft BASIC. Also in the ad is a 300 baud direct connect modem modem (a convenient alternative to an acoustic coupler!) for $149 plus the cost of a cable. Terminal software (Videotex) was available separately for $29.95 and Compuserve is also mentioned in the ad.

    The original CoCo was replaced by the CoCo 2 in 1983 (in 16K or 64K varieties) which was functionally identical and then by the CoCo 3 in 1986 which remained mostly compatible but offered some enhancements, including 128K of RAM, composite and RGB output, a slightly faster CPU and improved graphics modes among others. The CoCo 3 would be produced until 1991.



    Computer Arcana TRS-80 📎and tagged