Editing Tandy 1000 (section)

===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.