TANDY 600 FAQ -------------------------------------------------------------------------- About this FAQ This is the Tandy 600 FAQ. Perhaps the name "FAQ" is a misnomer, since questions about the 600 are very *in*frequent on comp.sys.tandy. Sources Much of the information in this FAQ comes from Tandy documentation and the December 1985 issue of Byte ("Product Description" article, page 118), and from my own experiences. Contacting the author Please send additions or corrections to Larry Kollar (lekollar@nyx.net) . I will credit you unless you specifically tell me to leave your name off. Disclaimer Nothing in this FAQ may be right. Proceed accordingly. (Now how's *THAT* for cutting through the legalese? :-) Version This is the Dec. 1996 version of the FAQ. The latest version can be found on: http://www.nyx.net/~lekollar/t600.html About the Tandy 600 Hardware Description The Tandy 600 (T600) was the last non-DOS laptop in the Tandy lineup. Announced on October 28, 1985, it was designed to address many of the shortcomings of the Model 100 and 200 laptops -- it sported a larger screen, more RAM, and a built-in disk drive. Unfortunately, its increased size, weight (9.5 pounds), and price tag ($1599 to $2400, depending on installed memory) -- not to mention the emergence of DOS-based laptops -- doomed it in the marketplace. [If any Tandy insiders know how many were built, I'd like to know.] The T600 resembles a conventional laptop more than the "slab" form of the T100. It had a flip-up 80x16 LCD screen, a keyboard that resembled the Model 200's, a built-in 300 bps modem, serial and parallel ports, and an external disk drive port. The base-level T600 shipped with 32K of RAM. Up to two additional 96K RAM modules could be installed, providing a maximum of 224K. Like the Model 100/200 (and modern PDAs!), the T600 used its RAM to store files and programs. A built-in 3-1/2" disk drive provided additional file storage (and backup). The T600 was rather cramped for space without at least one extra RAM module. The T600 ran on an internal NiCad battery pack (four high-capacity D cells) and an external power supply/charger. By minimizing disk and serial port usage, one could get up to 11 hours of computing time between recharges. (Hmmm, how long do most modern laptops go? 4-6 hours? And we call this progress...) Built-in software The T600 came with Microsoft Works V1.20 in ROM and a small complement of utilities on disk. Microsoft Works included: - Word: a more full-featured word processor than the T100/200. Word supports margins, merge, search and replace, and a rudimentary clipboard. - Calendar: a combination appointment book and task manager. You can set the T600 to beep when it was time for your next appointment. - File: a rather strange database. The T600 disk software included a library file that allows BASIC programs to access database files. - Telcom: A VT52 emulator with Xmodem file transfer capability. - Multiplan: What Microsoft used to call a spreadsheet; now they call Excel a spreadsheet. :-) Multiplan came on a snap-in ROM chip, accessible through a cover on the bottom of the laptop. You can remove this chip to plug in the BASIC chip. - Calculator: A four-function calculator with memory. Press CTRL-F2 to bring up the calculator from any application. - Alarm: Displays (and optionally sounds) an alarm for designated Calendar events. Press CTRL-F3 to bring up the alarm from any application. The System Manager provided access to built-in and optional software, file copies between the T600's RAM disk and floppy drive, and auto- matic wake-up and shutdown timers. Notably missing from the lineup was BASIC. Tandy provided an optional ($129.95) BASIC on a snap-in ROM chip (replacing Multiplan) and on a floppy. Hardware questions - WHERE is the battery/WHAT is it? Does Radio Shack still carry replacements? The battery is buried inside the case. If it has gone sour, you can make a new one using four of Radio Shack's "high-capacity" D-cell NiCads. Soldering wires onto battery terminals is probably more trouble than it's worth -- try holding the batteries together with electrical tape. - My system didn't come with a DC adapter. What does it need? Feed it 8V, 1.5 amp. Center pin is ground. I don't know if the 7808 regulators come in 1.5A versions; if so, it would be easy to rig up something with a cheap 12V power supply. - Where can I get extra RAM modules? In the March 1992 issue of Portable 100, Purple Computing listed the T600 96K module for $99 each (if you think *that* is steep, note that Tandy originally sold their upgrade modules for $399.95 PLUS INSTALLATION). While Purple Computing itself is no more, the man who runs it is still around. What's more, as of May 1995 he had a few T600 RAM modules available. The 800 number has long been disconnected, but a call to directory assistance turned up a long-distance number (see below). Purple Computing P.O. Box 100 2048 Southside Rd. Murphy, OR 97533 503-479-8087 FAX: 503-479-8089 - What type of modem is built-in? 300 bps. The serial port supports speeds up to 19,200 bps, but practical throughput is 2400 bps (since TELCOM uses slooooowww BIOS calls). TELCOM supports Xmodem out of the box, so that's one less thing to worry about. - What kind of cable do I need for the modem/parallel port? The T600's modem and parallel ports use the same cables as the Model 100. You may still be able to special-order these cables from Radio Shack. Old stuff like that occasionally turns up in store clearance bins as well. - What type of 3.5" drive does it have (single or double density)? Can you read its disks on any other system? Single-sided double-density. 360K. I've successfully read T600 disks in a PC clone; I had less success with a Mac -- it read the directory, but couldn't get most files. I believe the Amiga's MS-DOS disk handler can be configured to read them too. - How do I plug in a second disk drive? You're not going to believe this -- use a straight-through ribbon cable from the port on the back of the T600 to the drive. You'll need to power the disk drive from an external source. Find an old Amiga or PC double-density (720K) drive; I don't think a high- density drive will work. - What are the five chips behind the cover on the bottom? One is the socket for a snap-in ROM. The T600 came standard with Multiplan; BASIC was an optional program available on ROM and disk. The other four chips here are ROMs that contain the system software. Taking those out have a deleterious effect on system operation. :-) Software issues - Where can I get software? CompuServe has (or had) an archive of T600 software. Unfortunately, none of its contents has ever (to my knowledge) shown up on an FTP site. If you don't do CompuServe, you may be able to port Model 100 BASIC programs assuming you have the BASIC chip. I have a small collection of stuff on disks; if someone is willing to donate FTP space, let me know and I'll upload what I have. - Is it IBM compatible? It uses a CMOS 8088, but does NOT run DOS. It has an early version of Microsoft Works (1.02) in ROM. - What model(s) of Tandy computers is it compatible with? Chances are, most Model 100/200 BASIC programs will run on the 600 with a little twiddling. The T600 uses a different CPU from the 100/200, so you won't be able to use .CO (Model 100 machine language) programs, or BASIC programs that use PEEK and POKE, with the T600. (PEEK and POKE are not included in T600 BASIC, but are available through UTILITY.LIB.) - How do I get out of Word (or File, or whatever)? Press CTRL-F10 to return to the System Manager, or CTRL-F9 to switch to the last application. In BASIC, you can also type SYSTEM or QUIT to get back to the System Manager. - Is there any way to translate Word documents to something a different computer will understand? There is a DOS Works translator for Word 6 (Windoze) on Microsoft's FTP site. I can't verify whether it works for not; I have Word 7 and it won't read the converter. If you want to try it, it's at: http://www.microsoft.com/word/FreeStuff/Conv60/wksdos.exe For Mac users, there may be a Claris XTND translator that works (pun not intended), but I couldn't find one on the Claris web site. You can also set the left margin to 0 and print to a file to make a plain text file. - I can't get Telcom to work through the serial port! You need to wire up the modem control lines (4, 5, 6, and 20) as well as the standard data and ground lines (2, 3, and 7). Telcom doesn't recognize the connection until it sees (I think) DTR. Technical questions - I have a T600 that hasn't been used in a *long* time, and I can't get it to come up (or the screen displays garbage). Try turning off the battery switch (on the bottom of the computer) for about 30 seconds. Turn it back on, then push the reset button on the left side of the computer near the keyboard. If that doesn't work, try BS-ALT-LABEL-POWER (let go of POWER first; this is the cold start sequence). Either one of these sequences will wipe all files in RAM. But if you're at this point, you've probably lost them already. That disk drive makes an excellent backup device.... - How do I write machine language programs? First, get an 8086 assembler for your desktop computer. Then head down to your local Radio Shack and have them special-order part number 26-3901 (service manual and BIOS reference, $60). The info is there, but you may need to dig for what you want. Crashes will probably wipe out your RAM files, so backup early and often. - I opened BASIC, and it said I have 62533 bytes free. Say what? The System Manager shows over 100K free! Programs and files have a maximum size of 64K (65536 bytes). BASIC uses a little space for overhead. If you need more room for your BASIC masterpiece, split the program into several pieces and call them using "RUN filename." - What's the newline sequence? Carriage return only, same as the Model 100 and Macintosh. Miscellaneous questions - What good is it? What good is any computer? If you intend to spend more than a few hours away from a convenient AC outlet, or your power lines go down in an ice storm, the T600 will outlast most modern laptops. I take mine on vacations, where its obvious age may well deter hotel room burglars. If you have the BASIC chip, write an adventure game and hand it to the kids to keep 'em quiet on long trips. Or down- load your Web pages into it and edit them offline (text is text, after all; you can write HTML on *anything*). It comes up *fast* -- it's usually ready to go before you can get your finger off the POWER button -- and always takes you right back to where you left off. Some people like the idea of having a computer that was built from off-the-shelf parts (no ASICs or PALs) -- here's one you can cart around with you. Since the service guide includes a complete set of schematics and troubleshooting procedures, you could cart it around for a long time to come. - Is it better than the Model 100/200? I doubt that most Model 100 enthusiasts are very envious of the T600. By comparison, the T600 is larger, heavier, and doesn't have as much software (and what exists isn't available on an FTP site). What's more, the T600 has no expansion port. Many of the Model 100's shortcomings have been addressed by third parties. On the other hand, adding all those improvements also adds to the weight and bulk of the Model 100. If you need extra RAM and a disk drive all the time, you might be better off with a T600. [The End] -- Larry Kollar, Dawsonville GA | *** Hatred is murder *** (1 Jn 3:15) lekollar@nyx.net | http://www.nyx.net/~lekollar/ "So don't try to turn my head away Flirtin' with disaster every day"