Tandy 1000

Description

The original Tandy 1000, model 25-1000, was released in 1984 and is an amalgamation of the standard "PC Clone" of the time, and the IBM PC Jr. Tandy initially started designing it in 1983 as a "PC Jr. Compatible" but quickly had to change the marketing to focus on PC Compatibility at launch when the IBM_PCjr failed to succeed in the market due to some poor design considerations. The Tandy 1000 however, made up for these in having a real, wired keyboard, 3 normal ISA expansion slots, 2 Floppy drives, and (mostly) standard connectors. The 1000 Line went on to spawn numerous future models and become one of the most popular computer lines of the 1980's.

Technical Details

The Tandy 1000 was basically an IBM PC Jr. with standard ISA expansion slots, a regular, normal, keyswitch equipped keyboard, and some standard ports, particularly for power and video (RGB & Composite). What set it apart from other PC clones at the time was that it featured the enhanced 320x200 and 225x160 pixel, 16-color graphics modes of the IBM PC Jr, as well as the Texas Instruments 3-voice sound (on top of the single-channel square wave blipper of the internal speaker for actually 4 channels). However, it differed from later models due to the lack of Direct Memory Access (DMA) from the factory, and the lack of provisions for an intel 8087 Math Co-Processor in this initial version. These issues were all rectified in successive Tandy 1000 models such as the 1000A and 1000HD.

Specifications

POWER - 65 Watts, Proprietary CASE - Tandy steel/plastic 3-slot proprietary CPU - Intel 8088 @4.77Mhz (no 8087 Support for co-processor) RAM - 256K w/o DMA (expandable to 384-640K using a ISA Expansion card that added DMA) FDD - 2x black 360K DSDD TEAC Floppy Drives 5.25" half height GFX - Tandy 16-color Graphics (taken from the PC Jr.) SND - Tandy 3-voice + Internala Speaker (taken from PC Jr.) O/S - MS-DOS 2.11 for the Tandy 1000 w/ Deskmate

Documentation

• Tandy 1000 MS-DOS Reference Manual (25-1508)
• A Guide to the Tandy 1000
• Tandy 1000 Programmer's Reference (25-1503)

Troubleshooting

Compatibility Notes

In response to Howard Benner's request, I'll tell you what I know about
Tandy 1000 program compatibility (and some other stuff)...

First a general statement -- some large programs will require more
memory on your T-1000 than on a PC.  Reasons are we use 16K of RAM for video
(same as PC Jr), where the PC has separate dedicated RAM.  And, BASIC on
the T-1000 is loaded into RAM, where on the PC, part of it is in ROM.  The
difference, I hear, is about 48K.

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Programs we know will NOT run
(please EMAIL us if you find others):

"Math Blaster" - Davidson & Associates
"MasterType" - Scarborough Software	(late report - "MasterTypeII" runs)
"Alphabet Zoo"(IBM Version) - Spinnaker
"Murder by the Dozen" - CBS Software

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Caveats you should be aware of:

1. Some large programs will require more memory on the T-1000 than on the PC.

2. It's possible a few will require DMA (included in first memory upgrade).

3. IBM's keyboard is different, so there will be some adjustments to make...
for example, in Microsoft's "Flight Simulator", you can't use our separate
arrow keys.  You'll have to use the numeric keypad keys where the arrows
are on the PC.	Another is IBM's [SCROLL LOCK]... on the T-1000, you use
[CTRL][BREAK].	I'm sure there will be some other differences, but don't know
them personally.  Can anyone add any for me?

4. On some T-1000's shipped prior to 12/15, some IBM software wouldn't print on
a Tandy printer.  It was a bug in the hardware that's been fixed.  If you have
one of these early models, and experience the problem, return the 1000
for a modification.  If it ain't broke, don't fix it!

5. On the off chance that a program is written in BASIC, and you "acquire" a
copy on a disk with PC-DOS, you can boot, but not run it.  Remember, part
of IBM's BASIC is in ROM!

6. It's possible that a BASIC program might generate FC or Syntax errors on
a T-1000.  The preliminary version of BASIC does have a few incompatibilities
(don't know exactly what), but a new release expected in March will be more
compatible and faster.	NOTE: this is a POTENTIAL "gotcha", but I haven't heard
any complaints yet.

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What will be different about "Tandy versions" of software for the
Tandy 1000?

1. Manuals will be specific to your machine, and keyboard.

2. Some, like "Flight Simulator" will take advantage of the T-1000's enhanced
graphics and/or sound.

3. Our versions of printing programs will support Tandy peripherals, use our
printer codes, etc.  If you have a non-Tandy printer, buy the IBM package.
Of course our LATEST printers have switchable modes... Tandy or IBM.  Why
didn't we make those programs support IBM instead of Tandy add-ons?  Because
a LOT of upgrading Tandy owners will own older Tandy peripherals.  We don't
want them to have to buy a new printer to be able to upgrade.  Remember 1) IBM
versions of the program are available in the open market for those who need
them.  2) New Tandy printers will be mode selectable, to run with either.

Right now, those printers that have switchable modes are the DMP-2100P
and the DMP-430.

PRINTER WARNING: An Okidata "Microline 80" will damage your T-1000
if attached, due to high voltage on one of the printer's pins.	Either your
printer or T-1000 can be modified to eliminate the problem, without
affecting the printer's operation with another computer.

Serial printer support will be possible via the MODE command,
which will be implemented in MS-DOS 2.11.01, available late Feb/early Mar.

See Also

• Tandy Corporation