tcolegrove
Experienced Member
Hey all. I just listed an extremely rare MOS MCS6501 CPU on Ebay. Penny auction no reserve. https://www.ebay.com/itm/265718367024
"The MCS6501 is a first and very rare member of the MOS Technology 65xx CPU family. Introduced in 1975 with the MCS6502 to MCS6505, it was pin compatible with the Motorola 6800 and, after legal issues, was not produced afterwards. This particular example is date coded 4575, the 45th week of 1975. The chip is in excellent cosmetic condition. No testing has been done on the chip due to its rarity. It is sold AS-IS with no guarantee that it is operational.
The MCS6501 was sold with very few microcomputers of its day. The Digital Group and Ohio Scientific sold CPU boards that were compatible and Apple Computer famously specified the MCS 6501 as one of three CPU's compatible with the Apple-1 alongside the MCS6502 and Motorola 6800. According to Steve Wozniak the earliest prototype Apple-1's were built using the 6501 for testing purposes.
I purchased this CPU from the estate of David Towson of Baltimore, MD. David spent his career at the Department of the Army Signal Corps where he purchased it, along with several others, from his co-worker Bob Winterhalter sometime in 1977. Bob Winterhalter passed away 12/27/2010. According to handwritten notes that accompanied the CPU, it was tested good 10/7/77. It's unclear what Mr. Towson had hoped to do with the 6501's, but according to a note submitted to Bucknell University by his friend Bob Nevin, David was, "an engineer who never fails to impress me with his grasp of electronic circuits and never fails to amaze me with his ability to build them and make them work." According to Bob Nevin, David was a ham radio enthusiast in his spare time."
"The MCS6501 is a first and very rare member of the MOS Technology 65xx CPU family. Introduced in 1975 with the MCS6502 to MCS6505, it was pin compatible with the Motorola 6800 and, after legal issues, was not produced afterwards. This particular example is date coded 4575, the 45th week of 1975. The chip is in excellent cosmetic condition. No testing has been done on the chip due to its rarity. It is sold AS-IS with no guarantee that it is operational.
The MCS6501 was sold with very few microcomputers of its day. The Digital Group and Ohio Scientific sold CPU boards that were compatible and Apple Computer famously specified the MCS 6501 as one of three CPU's compatible with the Apple-1 alongside the MCS6502 and Motorola 6800. According to Steve Wozniak the earliest prototype Apple-1's were built using the 6501 for testing purposes.
I purchased this CPU from the estate of David Towson of Baltimore, MD. David spent his career at the Department of the Army Signal Corps where he purchased it, along with several others, from his co-worker Bob Winterhalter sometime in 1977. Bob Winterhalter passed away 12/27/2010. According to handwritten notes that accompanied the CPU, it was tested good 10/7/77. It's unclear what Mr. Towson had hoped to do with the 6501's, but according to a note submitted to Bucknell University by his friend Bob Nevin, David was, "an engineer who never fails to impress me with his grasp of electronic circuits and never fails to amaze me with his ability to build them and make them work." According to Bob Nevin, David was a ham radio enthusiast in his spare time."
