the first Atari with PCM audio; using a new chip, it added the ability to play back 8-bit (signed) samples at 6258 Hz, 12517 Hz, 25033 Hz, and even 50066 Hz, via direct memory access (DMA). The channels are arranged as either a mono track or a track of LRLRLRLR... bytes. RAM is now much more simply upgradable via SIMMs. Two enhanced joystick ports were added (two normal joysticks can be plugged into each port with an adapter), with the new connectors placed in more easily accessed locations on the side of the case. The enhanced joystick ports were re-used in the Atari Jaguar console and are compatible. The STE models initially had software and hardware conflicts resulting in some applications and video games written for the ST line being unstable or even completely unusable, primarily caused by programming direct hardware calls which bypassed the operating system. Furthermore, even having a joystick plugged in would sometimes cause strange behavior with a few applications (such as the WYSIWYG word-processor application 1st Word Plus). Very little use was made of the extra features of the STE: STE-enhanced and STE-only software was rare. The last STE machine, the Mega STE, is an STE in a grey Atari TT case that had a switchable 16 MHz, dual-bus design (16-bit external, 32-bit internal), optional Motorola 68881 FPU, built-in 1.44 MB "HD" 3-inch floppy disk drive, VME expansion slot, a network port (very similar to that used by Apple's LocalTalk) and an optional built-in 3" hard drive. It also shipped with TOS 2.00 (better support for hard drives, enhanced desktop interface, memory test, 1.44 MB floppy support, bug fixes). It was marketed as more affordable than a TT but more powerful than an ordinary ST. Atari TT In 1990, Atari released the high-end workstation-oriented Atari TT030, based on a 32 MHz Motorola 68030 processor. The "TT" name ("Thirty-two/Thirty-two") continued the nomenclature because the 68030 chip has 32-bit buses both internally and externally. Originally planned with a 68020 CPU, the TT has improved graphics and more powerful support chips. The case has a new design with an integrated hard-drive enclosure. Falcon The final model of ST computer is the Falcon030. Like the TT, it is 68030-based, at 16 MHz, but with improved video modes and an on-board Motorola 56001 audio digital signal processor. Like the Atari STE, it supports sampling frequencies above 44.1 kHz; the sampling master