![]() ![]() Another change was the move to depletion-load NMOS logic, a new technique that required only +5V. This led to the removal of one of the two accumulators and the use of smaller 8-bit index registers, both resulting in less internal wiring. One was that the designers stripped out any feature that wasn't absolutely required. ![]() There were three reasons for the 6502's low cost. In single-unit quantities, the 6502 sold for $25, whereas 6800 was initially aimed at $360, but had been lowered to $295 by this point. ![]() Peddle and a number of other members of the 6800 team left Motorola for MOS Technology and introduced this design in 1975 as the MOS Technology 6502. He began a project to produce a much less costly design, but Motorola's management proved uninterested and eventually told him to stop working on it. Notable among them was Chuck Peddle, who was sent on sales trips and saw prospective customers repeatedly reject the design as being too expensive for their intended uses. As a result, the 6800 had relatively low market acceptance after its release.Ī number of the 6800's designers were convinced that a lower-cost system would be key to widespread acceptance. To make a profit on the small number of chips that did work, the prices for the working models had to be fairly high, on the order of hundreds of dollars in small quantities. For complex multi-patterned designs like a CPU, this led to about 90% of the chips failing when tested. There was a small chance that some of the etching material would be left on the wafer when it was lifted, causing future chips patterned with the mask to fail. In this process, the photomask is placed in direct contact with the wafer, exposed, and then lifted off. The 6800 was initially fabricated using the then-current contact lithography process. A key feature was an on-chip voltage doubler allowed it to run on a single +5V supply, a major advantage over its competitors like the Intel 8080 which required -5, +5, -12 and ground. It was initially fabricated using early NMOS logic, which normally required several different power supply voltages. In overall design terms, it has a strong resemblance to other CPUs that were designed from the start as 8-bit designs, like the Intel 8080. The Motorola 6800 was designed beginning in 1971 and released in 1974. Main articles: Motorola 6800 and MOS Technology 6502 Hitachi was a major user of the 6809 and later produced an updated version as the Hitachi 6309. #TI 84 EMULATOR MAC DOWNLOAD SERIES#Series II of the Fairlight CMI digital audio workstation and Konami's Time Pilot '84 arcade game each use dual 6809 processors. The 6809 was used in the TRS-80 Color Computer, Dragon 32/64, and Thomson MO/TO home computers, the Vectrex game console, and early 1980s arcade machines including Star Wars, Defender, Robotron: 2084, Joust, and Gyruss. It was not feature competitive with newer designs and not price competitive with older ones. ![]() It was launched when a new generation of 16-bit processors were coming to market, like the Intel 8086, and 32-bit designs were on the horizon, including Motorola's own 68000. In 1980 a 6809 in single-unit quantities was $37 compared to $9 for a Zilog Z80 and $6 for a 6502. #TI 84 EMULATOR MAC DOWNLOAD CODE#Although source compatible with the earlier Motorola 6800, the 6809 offered significant improvements over it and 8-bit contempories like the MOS Technology 6502, including a hardware multiplication instruction, 16-bit arithmetic, system and user stack registers allowing re-entrant code, improved interrupts, position-independent code and an orthogonal instruction set architecture with a comprehensive set of addressing modes.Īmong the most powerful 8-bit processors of its era, it was also much more expensive. It was designed by Motorola's Terry Ritter and Joel Boney and introduced in 1978. The Motorola 6809 (" sixty-eight-oh-nine") is an 8-bit microprocessor CPU with some 16-bit features. ![]()
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