Tandy 1000EX

In 1980s Tandy was known in the U.S. of their TRS-80 line of home computers. Although PCs were typical office/business computers, release of IBM's PCjr made many companies to sell PCs re-designed for home computing applications. In late 1984 Tandy released Tandy 1000, a PC-compatible computer with some PCjr compatibility. Sold in their Radio Shack shops, PC became more popular than PCjr. Contrary to typical PCs, most peripherals were on mainboard as specialized chips, not in expansion boards.
In 1986 after success of Tandy 1000 and its variations, Tandy released Tandy 1000EX, a compact PC-compatible system, marketed as computer for PC beginners. It contains quite comfortable keyboard and 5.25" floppy disk drive in a single casing. It can use monitor or a TV. TGA graphics chip extended CGA to 16 colors in more graphics modes and 3-voice sound synthesizer, clone from PCjr, is still present.
The system has no ISA slots, but 62-pin goldpin connectors for boards stacked in parallel to each other. Not many expansions have been made, but the most popular were 256/384kB memory expansion boards as the computer had only 256kB of RAM on its mainboard.
Software bundled with Tandy PCs was always interesting. Here it's an early version of DeskMate called Personal DeskMate running on MS-DOS 2.11. The GUI shell had, on the desktop, widgets like calendar, calculator od notepad, as well as documents grouped by their type and set of PIM/Office programs which could be launched by opening a document or from menu. As of 1986 on a PC, not Mac, it is quite impressive. 1000EX has no software in ROM, as later Tandy PCs had.

Manufacturer Tandy

Origin USA
Year of unit 1986/7
Year of introduction 1986
Class XT
CPU Intel 8088
Speed 4.77MHz
RAM 512kB (256kB on board, 256kB on expansion), expandable up to 640kB
Graphics CGA (TGA - up to 16 colors)
Sound PC Speaker improvaed by Tandy chipset to 3-voice synthesizer
System expansion bus ISA using pin connectors
Floppy/removable media drives One 360kB 5.25" floppy drive (embedded), possible to use external FDD


Hard disk: None


Peripherals in collection:
 - None

Other boards:


Memory expansion
Non-standard expansions: None
Operating system(s): MS-DOS, originally 2.11
 + Personal DeskMate shell

My unit was purchased in a bad condition, having bad RAM and incomplete keyboard. It has been restored. Missing plastic cover for expansion slot has been replaced with another piece of plastic. Currently it runs well except floppy disk drive which is a bit out of alignment and can't read last tracks of some disks.

Contents: Starting, usage Pinouts Links


The machine is in most aspects PC-compatible. It starts, then boots OS from floppy disk. If external floppy disk drive is connected, it may boot from external disk. Most BIOS revisions then swap external and internal drive letters, so external one becomes A: and internal B:. This allows to omit bad floppy disk or use software on floppy disks in different formats.

System disks are in fact installation disks. They are copied/installed to user's disks in Tandy 1000, so you must have another blank disks to make system floppies from "raw" installation disks. On single-disk systems copying requires swapping disks. Personal Deskmate is relatively slow on 1000EX and requires much disk access, so before using it make sure the disk drive is in a good condition and floppy disk has no (or all marked) bad sectors on its surface.

DeskMate is operated from keyboard (Function keys!) or probably with joystick attached to its port (analog).

From Wikipedia, originally C. Howell




Important Pinouts:

According to this source:

Printer port (edge connector, upper side is 1,3,5...):

3 D0 4 GND
5 D1 6 GND
7 D2 8 GND
9 D3 10 GND
11 D4 12 GND
13 D5 14 NC
15 D6 16 GND
17 D7 18 GND
19 /ACK 20 GND
21 BUSY 22 GND
25 /SELECT 26 NC
29 NC 30 /INIT
31 GND 32 NC
33 GND 34 NC

Floppy disk port (edge connector, upper side is 1,3,5..., counting from right):

1 +12V 2 +5V
3 +12V 4 +5V
5 GND 6 +5V
7 GND 8 +5V
11 GND 12 /TRK0
13 GND 14 /STEP
15 /SIDE 16 /MOTOR
17 /DIR 18 GND
19 /WPROT 20 GND
21 /RDATA 22 GND
23 /WDATA 24 GND
25 /WGATE 26 GND
27 NC 28 +12V
29 /DSELECT 30 +12V

Joystick connector located near FDD:

1 - Y
2 - X
3 - GND
4 - FIRE1
5 - +5V
6 - FIRE1
Joysticks are analog.

Monitor output:

1 - GND
2 - GND
3 - Red
4 - Green
5 - Blue
6 - Intensity
7 - Green (monochrome)





https://web.archive.org/web/20080530020034/http://retrograde.trustno1.org/tandyroms.htm - Tandy 100 line ROMs
http://www.oldskool.org/guides/tvdog/1kfaq.html - Tandy PCs FAQ
http://www.brooksdeforest.com/tandy1000/ - Some games for Tandy 1000 which make use of Tandy's hardware.
http://www.radioshackcatalogs.com/catalogs/1987/pages/183.jpg - 1000EX in 1987 Radio Shack catalog,
http://support.radioshack.com/productinfo/DocumentResults.asp?sku_id=25-1050&Name=Tandy%20Desktops&Reuse=N - Radio Shack documentation
http://www.oldskool.org/guides/tvdog/index_html - TVDog site with information and photos of different Tandy PCs,
ftp://ftp.oldskool.org/pub/tvdog/tandy1000/ - TVDog's FTP related to Tandy 1000 series.
https://winworldpc.com/product/tandy-deskmate/personal-deskmate - Personal DeskMate Screenshots, binaries and manual.