MOS Technology

MOS Technology, Inc., briefly MOS, later also known as Commodore Semiconductor Group (CSG ), was a microprocessor and electronic computer components manufacturers, particularly known for the 6502 processor. It should not be confused with the company Mostek or MOS semiconductor technology itself. MOS is an acronym that stands for " Metal Oxide Semiconductor ".

Foundation

MOS was in the late 1960s as a subsidiary of the manufacturer of passive components, which, founded in Allen- Bradley Co. in Valley Forge Industrial Park in Pennsylvania. The product range in the first half of the 1970s were made ​​in TTL and MOS technology components for the booming calculator market, such as the 100-bit shift register MTS1001, the 256 -bit SRAM MCS2050, the character ROMs MOS2017 and MOS2020, the 90 -key keyboard encoder MCS1009 array and the clock generator MTS2517, later the calculator ICs MPS7529, MPS7530, MPS7541, MPS7542 MPS7545 and - partly second-source products for Texas Instruments chips.

The 6502

A crucial step for the company was the access of Bill Mensch, Chuck Peddle and six other former Motorola developers who had developed the 6800 processor on behalf of Olivetti at her former employer in 1974. Dissatisfied with the pricing policies of their former employer and full of ideas for improvement of their design they were planning now to design a similar processor, but with smaller chip area and thus cheaper by they wanted to omit unnecessary register, but the processor should get better addressing modes. Out came the MCS6501 - processor NMOS technology, which was offered in 1975 for $ 20 (less than 1/10 of the price of the then competing Intel processors ). Since he was pin-compatible to the 6800 processor, the company MOS but was sued by Motorola and had to take 6501 off the market.

The same Offered for U.S. $ 25 6502 but was not pin-compatible and had, in contrast to 6501 already an integrated clock generator, he could continue to use the Motorola peripheral chips and was - also in different controller versions - to great success. Presented at the WESCON75 he was discovered there, inter alia, by Steve Wozniak and used by him in the Apple I and Apple II. He was also appointed by the chip designer Chuck Peddle in PET 2001 and later by Commodore in VC20, but also in Atari and many other home computers. In the summer of 1976 put the MOS KIM-1 microcomputer system with the MCS6502 before CPU.

Takeover by Commodore

In September 1976, the company, which had come by the collapse of the calculator chip market and the lawsuit filed by Motorola in trouble was, by Commodore - the time of their largest customer, the calculator ICs - purchased and produced henceforth under the name "Commodore Semiconductor Group" with headquartered in Norristown, Pennsylvania, most chips for the Commodore products, further wherein the imprint MOS was used on the ICs for practical reasons. The company failed to develop the successful 65XX processor line (which, for example, by the before the takeover excreted William D. Man Jr. in which he founded company Western Design Center with the 16- Bitter 65816 and the low-power 6502 - CMOS version 65C02 was ).

In the Commodore time the company has developed not only the various versions of the 6502 CPU ( see Commodore 64 and C128 ), but also the associated peripheral chips VIC, CIA and SID that is designed ( and Others by Bob Yannes was ). For the Amiga model in addition to the modified CIA chips, the custom chips were also made ​​, which accounted for the Amiga from a hardware perspective.

After Commodore

Recently, the company managed in the late 1990s on the basis of chemical residues on the corporate campus in Montgomery County, Pennsylvania in the local headlines. The company's location was listed as a problem area since 1989 because of groundwater contamination with trichlorethylene and other volatile organic compounds in the Environmental Protection Agency (EPA).

Following the liquidation of Commodore in 1994, the CSG was sold to GMT Microelectronics Corporation. This operation in subsequent years at the former company site, chip production by the year 2001. During 2001 GMT was liquidated by the EPA because of groundwater contamination and the associated high costs.

Others

Other companies built under license by the 8 -bit processors, including Rockwell International (hence there are the names M6502 and R6502 ) and Synertek ( SY6502 ). In the Eastern Bloc Bulgarian manufacturer Pravets built the chip in without a license under the name CM630P, the chip was also used in the Apple II clones Pravets Pravets -82 -8A and this manufacturer.

Articles on individual chips of the company:

• 6502 and variants
• 6507
• VIA ( 6522 )
• CIA ( 6526, 8520/1 )
• SID ( 6581/2, 8580 )
• TED ( 7360 )
• VDC ( 8563/8 )
• VIC ( 6560/1 )
• VIC II ( 6567/9, 8562/5 )
• ACIA ( 6551 )
• Original Chip Set (OCS ), Enhanced Chip Set (ECS ), Advanced Graphics Architecture (AGA or AA)
• Agnus ( with blitter and Copper), Paula