Editing Tandy 1000 (section)

==Technical details==
All Tandy 1000 computers feature built-in video hardware, enhanced sound hardware (based on one of several variants of the Texas Instruments [[Texas Instruments SN76489|SN76496]] sound generator) and several peripheral interfaces, including game ports compatible with those on the [[TRS-80 Color Computer]], an IBM-standard floppy-disk controller supporting two drives, and a parallel printer port, all integrated into the motherboard in addition to the hardware standard on the IBM PC/XT and, in later Tandy 1000 models, PC/AT motherboards.

For the original Tandy 1000, the designers omitted a [[direct memory access]] (DMA) controller because the PCjr does not have one, and they believed that those who needed it would add it with additional memory for the computer; they omitted the [[RS-232]] port because all Tandy printers use the parallel port and, they believed, most customers would use internal modems.<ref name="vose198412">{{Cite magazine |last=Vose |first=G. Michael |date=December 1984 |title=The Tandy 1000 |url=https://archive.org/stream/byte-magazine-1984-12/1984_12_BYTE_09-13_Communications#page/n99/mode/2up |magazine=BYTE |pages=98–104}}</ref> The earlier models of the Tandy 1000 have a composite video output, and can be used with a color or monochrome composite monitor, or a TV with an RF modulator. The original 1000 and SX has a light-pen port. Unlike most PC clones, several Tandy 1000 computers have [[MS-DOS]] built into [[read-only memory|ROM]] and can boot in a few seconds. Tandy bundled [[DeskMate]], a graphical suite of consumer-oriented applications, with various Tandy 1000 models. 
 
Early Tandy 1000 models use [[Phoenix Technologies|Phoenix BIOS]]. Common models of the machine include the Tandy 1000, 1000 EX, 1000 HX, 1000 SX, 1000 TX, 1000 SL, 1000 RL, and 1000 TL. With the exception of the RLX and RSX, the Tandy 1000 machines are XT-class machines, which cannot support [[extended memory]] despite some models using 80286 processors. The RLX is an oddity, as it is an XT-class machine that supports 384&nbsp;KB of extended memory, and the RSX is a fully AT-class machine which can support up to 9&nbsp;MB of extended memory.

=== Expansion slots ===
With the exception of the 1000 EX and HX, Tandy used industry standard 8-bit XT ISA slots in their desktop models, including the SX, TX, SL, and TL series, but the actual length is limited to 10.5 inches or shorter, rather than the industry standard XT length of 13 inches. While many 8-bit cards meet this length requirement, some cards such as hard cards, EMS memory cards, and multifunction cards that require the standard 13" length do not fit in the 1000s case. The EX and HX utilize a PLUS-style connector, which is electronically identical to an 8-bit XT ISA slot, but has a 62-pin [[pin header]] instead of a card edge, rendering it incompatible with ISA cards without an adapter. The PLUS connector was designed for compactness in these models with built-in keyboards. The 1000 RSX features two 16-bit AT ISA slots.

===Hard disk drives===
As hard disk drives at the time of the Tandy 1000's introduction were very expensive, Tandy 1000 systems are not usually equipped with hard drives. However, it is possible to add a hard drive to most Tandy 1000 computers. Most of the desktop-type Tandy 1000 units can accept regular 8-bit [[Industry Standard Architecture|ISA]] bus [[Modified Frequency Modulation|MFM]], [[Run-length limited|RLL]] and [[SCSI]] controllers like typical XT-class machines; however, care has to be taken when configuring the cards so that they do not cause conflicts with the on-board Tandy-designed peripherals.

For most Tandy 1000 models (other than the compact EX and HX) that do not come equipped with a hard drive, Tandy offered hard disk options in the form of [[hardcard]]s that are installed in one of the computer's expansion slots and consist of a controller and drive (typically a 3.5-inch MFM or RLL unit with a Western Digital controller) mounted together on a metal bracket. Their own 20 MB hard card was offered for $799, though compatible third-party units were available. Although this arrangement provides a neat physical coupling between the controller and the disk, single-sector internal transfers and dependence on the speed of the host machine to transfer data to memory means that a trial-and-error approach was still needed to set the disk [[interleaving (disk storage)|interleave]] correctly to ensure optimum transfer rates. Furthermore, as the Tandy 1000's slots are only 10.5" long and are 8-bit only, some units do not fit and/or operate correctly unless they are certified to be Tandy-compatible.

Starting with the Tandy 1000 TL/2, XT IDE controllers are integrated onto the motherboard. However, these are incompatible with common AT IDE hard drives. The TL/2, TL/3, RL and RLX all use the XT IDE interface, where the later (and significantly upgraded) RSX is the only Tandy 1000 model computer to use a standard [[Integrated Drive Electronics|AT IDE]] interface. One option for modern users of these systems is to install and use XT ISA CompactFlash adapter; this is also the most practical way to install a hard drive into a Tandy 1000 EX or HX, using an adapter cable that adapts the male PLUS-style connector to an 8-bit ISA card-edge slot.

=== I/O and ports ===
Tandy 1000, SX, and TX use a proprietary 8-pin round DIN connector for the keyboard port that is compatible with the older TRS computers but not compatible with the [[IBM Personal Computer/AT|IBM PC/AT]] or PS/2 standard. Some scan codes differ between the Tandy 1000 and IBM PC/XT and AT, resulting in software compatibility issues. The SL/TL and later use a more directly PC/XT-compatible keyboard protocol, and the 1000 RSX uses a PC/AT and PS/2-compatible protocol.

Tandy 1000 uses a proprietary 6-pin female round connector for the joystick port that on the SX/TX is adjacent to the keyboard port in the front of the computer. It is compatible with Color Computer joysticks, but not compatible with the IBM standard 15-pin male game port. Some DOS games do not work with these joystick ports, but those that support Tandy 1000 graphics and sound work.

Early Tandy 1000 models use the TRS-80 card-edge parallel printer port rather than industry standard DB-25 printer port, requiring a compatible printer cable to connect to a standard printer parallel port. This was later changed to a standard DB-25 connector on the 1000 RL.

Tandy 1000TX and beyond use a proprietary floppy drive cable port, that also powers the floppy drive. It requires a Tandy 1000-compatible floppy drive, though it may be possible to modify a floppy drive cable to make a standard floppy drive work.

=== Operating systems and environments ===
Tandy shipped PCs with their own customized version of [[MS-DOS]], which are compatible with Tandy graphics and keyboard. The most current version of MS-DOS for Tandy 1000 is DOS 3.22. Tandy 1000s came shipped with one of several varieties of [[DeskMate]], the company's own [[graphical user interface|GUI]] productivity software suite.

There may be compatibility issues with later versions of DOS such as DOS 5 and DOS 6. Until the 1000 RLX, Tandy 1000s are typically limited to 640&nbsp;KB main memory, and non-Tandy versions of DOS often reduce the memory available for applications and games. In addition, the hardware detection routine for the installer of Microsoft MS-DOS 6 can corrupt the serial EEPROM of Tandy 1000 HX machines.<ref name="dos60ref">{{Cite web |title=MS-DOS 6.0 UPGRADE PACKAGE |url=ftp://ftp.oldskool.org/pub/tvdog/tandy1000/documents/dos60.txt |access-date=2023-05-30 |archive-date=2022-08-06 |archive-url=https://web.archive.org/web/20220806054244/ftp://ftp.oldskool.org/pub/tvdog/tandy1000/documents/dos60.txt |url-status=bot: unknown }}</ref>

Tandy 1000s can work with [[Windows 1.0]], [[Windows 2.0|2.0]], and [[Windows 3.0|3.0]] but not [[Windows 3.1x|3.1]], with the exception of the RLX which can run Windows 3.1 in Standard mode,<ref name=TVDogPics>{{Cite web|url=http://www.oldskool.org/guides/tvdog/RLRLX.html|title = Tandy 1000RL and RLX Pictures}}</ref> and the RSX which fully supports Windows 3.1 in 386 Enhanced mode.<ref name=TVDogPics />

=== Peripherals ===

==== Monitors ====
Tandy offered two color monitors specific for its Tandy 1000 computers: the CM-5, with a 0.64 millimeter dot pitch,<ref>{{cite web|title=CM-5 specifications|url=http://support.radioshack.com/support_accessories/doc4/4842.htm|website=radioshacksupport dot com|publisher=Tandy Corporation|access-date=May 15, 2017}}</ref> and the Tandy CM-11 with a dot pitch of 0.42&nbsp;mm.<ref>{{cite web|title=CM-11 specifications|url=http://support.radioshack.com/support_accessories/doc6/6012.htm|website=radioshacksupport dot com|publisher=Tandy Corporation|access-date=May 15, 2017}}</ref> Both are 13-inch displays and have a power cable and a nine-pin RGB cable to attach to the Tandy CGA port. The more expensive CM-11 also supports a special proprietary Tandy-enhanced 225 scan line text display mode.

Tandy also offered monochrome monitors that support MDA and Hercules standard that also work with Tandy 1000. As it uses a CGA-compatible interface, non-Tandy monitors that support CGA should work.

==== Keyboard ====
The original Tandy 1000, SX, EX, TX, HX use a proprietary keyboard and keyboard layout that is not compatible with the PC/XT/AT standard. The layout of the keyboard prefigured the [[IBM Model M]] keyboard, with function keys arranged in a row at the top, instead of on the left as in the PC and PC XT/AT. Later models of the Tandy 1000 series, such as the 1000 SL, TL, and RL series use a keyboard more similar and compatible with the IBM PS/2 series keyboard connector and layout.

==== Mouse options ====
As the Tandy 1000 uses the same game ports as the Tandy Color Computer series, the 26-3025 Color Mouse and 26-3125 Deluxe Mouse are compatible with the Tandy 1000, though not all DOS software and drivers recognize them. The Tandy Digi-Mouse requires a separate controller that was available in either ISA or PLUS format. Systems with RS-232C serial ports can use standard serial mice, and later systems, such as the 1000 RL, feature a PS/2 mouse connector.

==== Joystick options ====

Radio Shack offered a two-button [[joystick]] with its proprietary 6-pin DIN joystick connector that is compatible with the older [[TRS-80 Color Computer]] but not standard 15-pin IBM PC game ports often found on sound cards and i/o multifunction ISA cards. It works with many games written to take advantage of Tandy graphics and sound.

==== Modem options ====

Radio Shack offered Tandy 1000 PLUS 300-Baud PC Modem that is compatible with the 1000EX/HX that used PLUS slots. Radio Shack also offered 2400-baud internal modem. Third party modems with speeds of 14k baud should work provided they are eight-bit ISA, and fit.

==== Printers ====
Radio Shack sold the Tandy DMP-130A dot matrix printers to go along with their Tandy 1000 line, along with compatible card-edged printer cable. This printer was sold at home budget prices. Radio Shack often offered a package bundle with a Tandy 1000 computer, CM-5 budget monitor and DMP-130A printer. Using specially-designed aftermarket cables, it is possible to connect non-Tandy printers to the system.

==== Apple IIe compatibility ====
 
Tandy wanted to compete in the education, school and home markets dominated by the [[Apple IIe]]. In 1987, the company partnered with [[Diamond Multimedia|Diamond]] and through Radio Shack sold the [[Diamond Trackstar 128]] series Apple IIe compatibility board for $399, and offered free installation in their Tandy 1000 series. This peripheral is similar to the [[Apple IIe Card]] sold later for certain Macintosh models; it is a fully functional Apple IIe clone with 128KB RAM and 6502 CPU and double high-resolution graphics, which allows Tandy 1000 computers to run software written for the Apple IIe and IIc platform. It was also marketed to home users and businesses interested in having both MS-DOS and Apple II compatibility.

The board has a pass-through RGB cable and floppy drive cable, and requires an open 10-inch 8-bit ISA slot, and uses a boot disk to boot into Apple mode. The boot disk has both DOS and Apple software and is [[Copy protection|copy-protected]]. Compatibility is fairly good and allows Tandy 1000 owners to run most Apple II software on their Tandy 1000 machine for less than the cost of owning separate IBM PC and Apple II systems.

Many Tandy 1000s sold to schools came with the Diamond Trackstar 128 installed,<ref>{{Cite web|url=http://www.applelogic.org/Trackstar.html|title = Trackstar}}</ref> and home owners also purchased this for compatibility with both DOS and Apple II software.<ref>{{Cite web|url=https://www.diskman.com/presents/trackstar/|title = Trackstar: The Apple II clone inside an IBM PC}}</ref>