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. 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 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 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 KB of extended memory, and the RSX is a fully AT-class machine which can support up to 9 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 1000's 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 Berg connector instead of a card edge, rendering it incompatible with ISA cards without an adapter. The PLUS connector was designed for compactness in