Welcome back to part 2 of my fifth SepTandy Spectacular. In the last post we took a Tandy 10. In this post we'll have a look at the more famous machine that replaced it, The TRS-80 Model II.
The TRS80 Model 2 (1979).
Introduced in October of 1979, The TRS-80 Model II was launched just 2 years after the The TRS-80 Model I, and targeted at the small-business market. It boasted higher specs and managed to maintain success for many years.
Now im technically streching this a little as the TRS-80 Model II isn't exactly obscure, it just wasn't successfull in the same market that the Model I, III and IV did because it was a buisness machine and not a home machine. Still the machine is worth take a look at, and thats what were doing today!
The Story of the TRS-80 Model II begins in 1978, A year after the introduction of the TRS-80 Model I. Tandy was surprised at the strong demand for the TRS-80 Model I from business users, and were inspired into looking more into the buisness market.
But with the failure of the Tandy 10, It became clear to them that in order to have success, they needed to make their own machine that could combine the features of the Tandy 10 with the smaller and cheaper design of the TRS-80 Model I. The result was an all in one machine that was significantly smaller and cheaper than the Tandy 10 and was much better equipt to be a buisness computer.
TRS-80 Model II was announced in May 1979, and was officially released in October 1979, for a retail price of $3,450 dollars with 32K of RAM, or $3,899 dollars with 64K of RAM.
On the front of the machine is the built in monitor, the power switch, power light, a reset switch, one Singled-sided 8 inch floppy drive and a little storage area for the keyboard
The front of the TRS80 Model II
The screen is is similar to the Model I in that its a 12" black-and-white TV set; with the monitors supplied by both RCA and Motorola. However, Unlike the Model I, the RF, IF, and sound circutry were stripped out and it used higher quality componets, giving the Model II much better picture quality.
The disk drive in the Model II is A Shugart SA-800 full-height, single-sided 8" drive; like most such drives, it spins continuously whether the disk was being accessed or not and the motor is powered directly off the A/C line. The floppy controller in the Model II is a double-density, soft-sector unit based on the WD 1791 floppy controller. Like with the Model I/III/IV, boot disks on the Model II require Track 0 to be single density. CDC drives are used for the floppy expansion module. The disk format it used closely follows the IBM 3740 standard, with 77 tracks, 26 sectors per track, soft sector formatting, and a sector size of 128 bytes for a formatted capacity of about 250 KB, but the Model II had a double density controller, so the disk format uses 256 byte sectors and formatted capacity is about 492 KB. If users install a double-sided drive they can get 1 MB of space, but this requires a modified DOS and Radio Shack did not officially support the use of double-sided drives. This also gives it an advantage to increase the amout of software it can run, but more on this later.
The Keyboard is very similar to the TRS-80 Model I but has a few notable additions, including a numpad, HOLD, ESC, BREAK, CTRL, CAPS, REPEAT, F1, and F2 keys. The HOLD key pauses execution of a program, and the REPEAT Key engages the Typematic (Or the keyboard feature that repeats characters continuously).
The keyboard of the TRS-80 Model II
On the back is a disk drive port, a parrallel port, an Archnet port, 2 serial ports, a fuse for the disk drive and the power plug.
The back of the TRS-80 Model II
Powering up the TRS-80 Model II, we're greeted by a message stating the RAM amount (In this case, 64K), a quick test of the DMA and PIO, and a copyright screen for TRSDOS 1.1. Here were propted to enter the date and time. Its worth noting that like the earliest versions of MS-DOS, You HAVE to enter a date before entering the time. If you just hit return, it will just coem back with an TRY AGAIN message. After entering the date, we're dropped into TRSDOS. It opperates much like TRSDOS for the Model I.
For storage, you have the previously mentioned 8 Inch floppy drive, but you could also get of a disk drive expansion unit to have acess to 1, 2, or 3 extra drives to access up to 2 MB of storage.
For Printers, Radio Shack offered the TRS-80 Model II paired up with 3 different options: The Tractor Feed Line Printer for $1559 dollars plus the TRS-80 Model II interface for $39.00 dollars, The Line Printer II for $970.00 dollars plus the TRS-80 Model II interface for $29.00 dollars, or the The Line Printer III for $1960.00 dollars plus the TRS-80 Model II interface for $39.00 dollars. They also offered desks for the Line Printer I and III to sit on for $99.00 dollars and $139.00 dollars respectivly.
There was also a modular desk for the computer as well, designed to accomidate the computer and the disk drive unit and be rearaged in however the user wanted, for $350.00 dollars.
Radio Shack also offered the computer, desk, disk drives, and printers in bundles as well, providing a system configuration for every budget, much like they did for the Model I. There was the Starter System with the computer, Line Printer II, and Printer Cable for $4,898 dollars, The Step Up System with the computer, Line Printer, Printer Stand, and Printer Cable for $5,946 dollars, The 1.5-Megabyte Deluxe Business System with the computer, 2 drives, Line Printer III, and Printer Cable for $7,898 dollars, and the 2-Megabyte Business Management System, with the computer, 3 drives, Line Printer III, Line Printer III Stand, and Printer Cable for $8,737 dollars.
Later on the bundles changed slightly to the Starter System having the computer, Line Printer II, and Printer Cable for $4,727 dollars, The Basic Buisness System with the computer, Line Printer VI, Printer Stand, and Printer Cable for $5,467 dollars, The Word Processing System with the computer, 2 drives, Daisy Wheel Printer II, Printer Cable, and a copy of Scripsit for $6,197 dollars, The 1.5-Megabyte Deluxe Business System with the computer, 2 drives, Line Printer III, and Printer Cable for $8,017 dollars, and the 2-Megabyte Business Management System, with the computer, 3 drives, Line Printer III, Line Printer III Stand, and Printer Cable for $8,766 dollars.
For hardware, the Model II uses a Z80A CPU clocked at 4 MHz, 32K or 64K of RAM, and 2K of ROM. The reason why the ROM is so small is that the system was designed to load its BIOS Routiens from a small boot loader on the system disk, which allows for almost all of the Model II's memory can be used by software.
Another interesting thing about the Model II is that its a backplane based system. There are 8 expansion slots and the CPU, RAM, ROM, Video, I/O, and Floppy Controllers all live on cards that are pre instaled into 4 of those slots. Now while the slots look like S-100 Bus Ports, they aren't. Their propriatary ports and are completely incompatable. However Radio Shack offered various cards like a High resolution graphics expansion board with a modified BASIC providing rudimentary screen drawing capabilities like line, box and circle drawing, shading and filling, a viewport capability, and array transfer between graphics RAM and CPU RAM, a hard disk controller, and a network interface controller.
The graphics are displayed at a text resolution of 80 columns by 24 rows, as well as 40 columns by 24 rows, far higher than the Model I and far more suitble for buisness use. The character set is also different as it includes several mathematics and currency symbols, and in place of the Model I's semigraphics characters has 30 characters (ASCII codes 128-158) for drawing lines and boxes.
Much like the Model I, there is no sound for the computer, and unlike the Model I, theres no cassette port for hooking up a speaker to. This wasn't much of a problem though, as sound wasn't much of a requirement for buisness use.
As for software, Most of it was buisness software (as you would probably expect), and the Model II hosted its far variaty of buisness software, from Word Processors, to Spreadsheets, to Database Applications. While I wont go into all of them because they wouldn't be all that interesting to look at, i will go over some of the most popular.
As previously mentioned, one popular aplication that was offered for the Model II was Scripsit. Although Scripsit was originally released back in 1978 for the Model I, Radio Shack also created a version specifically for the Model II. Taking advantage of all of its features to provide a decent Word Processing package for the time, complete with variable width fonts for daisy-wheel printers and lowercase letters.
As for software, Most of it was buisness software (as you would probably expect), and the Model II hosted its far variaty of buisness software, from Word Processors, to Spreadsheets, to Database Applications. While I wont go into all of them because they wouldn't be all that interesting to look at, i will go over some of the most popular.
As previously mentioned, one popular aplication that was offered for the Model II was Scripsit. Although Scripsit was originally released back in 1978 for the Model I, Radio Shack also created a version specifically for the Model II. Taking advantage of all of its features to provide a decent Word Processing package for the time, complete with variable width fonts for daisy-wheel printers and lowercase letters.
Another popular application was Visicalc, the very first spreadsheet program for personal computers, which aslo debut in October of 1979. While the original versionwas released for the Apple II, because it also receives the honor of being the first killer app, it proved popular enough to earn ports to othe computers, including the Model II. And it provides a nice display to work with as its a proper 80 collums instead of 40.
But despite being a buisness machine, there are a few games for it. Adventure International released versions of the Scott Adams text adventures for the system, Infocom released games such as Zork and The Hitchhiker's Guide to the Galaxy for the system, and there were even a few action and arcade games written in text mode.
However despite being in the TRS-80 Family it is incompatable with the Model I due to the differing hardware and software. However there is a work around for that. Enter Digital Researches CP/M opperating system,the very first Disk Opperating System (Or DOS) for Micro Computers.
After graduating, he fulfilled his draft obligation by teaching at the Naval Postgraduate School in Monterey, California in 1972, Where he learned about the first commercially available microprocessor, The Intel 4004. He imediatly became interested in programing and started consulting with Intel and writing software for their systems.
After returning to UW to obtain a degree in Computer Science, in 1973 he created the first high-level programming language for microprocessors, PL/M (Or Programming Language for Microcomputers) for the Intel Intellec-8 microcomputer, as well as CP/M (Or Control Program/Monitor, Later Controll Program for Microcomputers) to enable it to use a floppy drive.
Intel was impressed with PL/M, but didnt see much potential for CP/M, so they declined to market it. Thinking that it would be successful otherwise, Kildal and his wife Dorothy started started Intergalactic Digital Research in 1974 at their home in Pacific Grove, California, later renamed to Digital Research, Inc., or DRI, to develop CP/M into a fully-fledged operating system for 8080 and Z80 CPU's.
It consisted of 3 parts: the BIOS, the Basic Disk Operating System, and the Command Console. Each of which worked together to let multiple programs work with different hardware in a standardized way,this provided a complete operating environment for the myriad personal computers coming to market. DR liscened CP/M to hundreds of computer manufacturers including MITS, IMSAI, North Star, Osborne, Kaypro, Exidy, and Xerox.
It was so successfull, It even caught IBM's attention and almost became the OS for the IBM PC, Until Microsoft beat them to the punch by liscencing them an 8088 CP/M clone called 86DOS that they had purchased from Seatle Computer Products, which became PC-DOS and later MS-DOS.
This move effectivly killed CP/M by 1983 and DRI struggled on before going out of buisness in 1991. Kildal himself also met an unfortunate end as he got divorced, became an alcoholic, and died from a head injury at a biker bar in 1994.
But going back to CP/Ms early years, a typical CP/M system consisted of an 8080 or Z80 based machine, a Teletype or Dumb Terminal Display, and an 8 Inch floppy drive.
And thats where the TRS-80 Model II's built in drive comes in, Remeber how I said it closely followed the IBM 3740 standard earlier? Well thats where the drive and CP/M comes to its advantage. You see one problem that CP/M had that MS-DOS didnt have and partially why it overtook it, was that while the OS was standardized the Disk format was not, At least on 5.25 inch based systems. 8 inch drive based systems used drives based on the IBM 3740 standard as well and the Model II was built with this in mind.
Not only could the Model II run standard CP/M right out of the box, but it could also run CP/M from third party providers that had the ability to share CP/M disks between the Model I, II , III and IV. This allowed for the Model II to share programs between the I, III and IV, but also allowed it to run more popular CP/M aplications like Wordsat and Super Calc.
In adition to all of this, Radio Shack also sold various software for accounting, medical office, legal office, payroll, inventory, order entry, and sales analysis. There were also various professional programing languages availible for it like FORTRAN, COBOL and Assembly, as well as software for data transfer with IBM mainframe computers.
So how did the Model II do in the Marketplace? Answer, Very well. In 1981, InfoWorld called the Model II "a well-designed, capable business system" that "overcomes several limitations of the Model I", and in 1984, Creative Computing called it a "state-of-the-art business machine" that "might have taken the business market by storm had it not had a nameplate reading 'Radio Shack.'"
Though much like the Model I, it did have its flaws, The keyboards for the Model I used Keytronic Foam and Foil switches which not only provided a quite litteral spongy feeling typing experence, but also was prone to disintegrating over time. A later version was made by Cherry, but still used the capacitive technology rather than the more well-known Cherry mechanical keyswitches.
Another problem was that the cooling fan provided was so loud, people were actually scared to use the computer! The case fan was added due to the heat generated by the 8" floppy drive's continuously running spindle motor powered directly from AC line voltage. The combined effect of the case fan and the floppy motor results in an extremely noisy computer, compared to the nearly silent Model I.
Still the Model II proved to be a major sucess in the buisness and industial market and was provided many hardware revisions over its life time. The first revision models (1979–80) couldn't boot from a hard drive, and the floppy controller required a terminating resistor pack for the last drive on the chain, instead of the standard method of putting a terminating resistor pack on the internal disk drives. The external resistor pack works by looping back the I/O lines on the external floppy connector to the SA-800 drive's terminator pins. This was chosen so users wouldn't have to remove the cover and install or remove a terminating resistor pack on the floppy drive every time they wanted to remove or attach external disk drives.
It proved problematic since customers tended their resistor packs, so Model II's sold from 1981 onward use a different floppy controller that does not require it. Hard disks offered for the Model II also use a terminating resistor pack. These were sold as master and slave drives, with the master hard disk (which has the resistor pack) needing to be the last one on the chain. Like most hard disks offered on 8-bit computers, there is no subdirectory support and the drive is treated by the OS as a large, fast floppy disk.
The Model II was succeeded by the compatible TRS-80 Model 12, Model 16, Model 16B, and the Tandy 6000.
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Left to right: The TRS-80 Model 16 (1982), The TRS-80 Model 12 (1983), The TRS-80 Model 16B (1984), and The Tandy 6000 (1985).
All of these machines continued to be supported until 1987, When Tandy announced that the 6000 hardware would no longer be improved, and in 1988, Radio Shack had begun offering IBM-compatible 386 PCs for their professional line, finally retirinf the Model II family.
The Model II's Successors are definatly deserve a SepTandy Spectacular of their own, but that wraps up our look at the TRS-80 Model II. This concludes part 2 of my fifth Septandy Spectacular, join me next time as we move forward take a look at the successor to the Tandy 100.
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