Robotics Education & Competition Foundation
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C64 teardown


Entry ID #: 1906
Created: Wed, Nov 11, 2015 9:34 AM

A teardown and explantion of the main chips within the 1984 computer, The Commadore 64. The Photos and 300 word report is in the DOCX file. EDIT: Doc file will not attach correctly. Report will be contained below. Photos will be uploaded to imgur and placed in the links section.                                            BEGIN REPORT ------------------------------------------------------------------------------------------------   We chose the Commodore 64 (C64) as our project because we have not seen it entered in the Texas Instruments Online Challenge. The C64 was popular when it came out, selling nearly 12.5 million units. Its prolific status makes it an interesting topic to talk about, with research still going on into odd bugs and quirks of the machine.  The C64 also has historical value which has lent to the development of the modern computer systems. The processor and the PLA were the main chips we focused on.  The processor is an MOS 6502, which is a legendary CPU made famous by its use in many home computers. The PLA is a custom made chip that took years to be fully decoded by the community. The primary chip of the C64 is the 6502. This chip was sold at 1/6 the price of its competition. First produced commercially in 1975, it quickly outsold Intel and Motorola CPUs. It was started as part of the 6800 series at Motorola, but was ‘moved’ to MOS after several Motorola employees left for MOS. With 40 pins, there are a ton of features which include edge sensitive NMI and many hardware interrupts. The PLA is responsible for dictating the memory map and bank switching. The overall design of the PLA is not very complex making it challenging to work with NMOS at the time. While the memory map is flexible, very few programs altered the memory map. This allowed ROM based PLAs to be used as temporary fixes, with hardware becoming scarce. The C64 is an amazing computer with a unique processor and PLA, it was certainly interesting to re-learn what I had forgotten after my initial research on my own time. It was overall an excellent way to test my existing knowledge. ------------------------------------------------------------------------------------------------                                 END REPORT                                   WORKS CITED Giesel, Thomas. The C64 PLA Dissected.  "Motorola Sues MOS Technology" (PDF). Microcomputer Digest (Cupertino CA: Microcomputer Associates) 2 (6): p. 11. December 1975. ‚Äč"Motorola joins microprocessor race with 8-bit entry". Electronics (New York: McGraw-Hill) 47 (5): pp. 29–30. March 7, 1974.  Motorola 6800 Oral History (2008), p. 9 Mensch Oral History (1995) Mensch earned an Associate degree from Temple University in 1966 and then worked at Philco Ford as an electronics technician before attending the University of Arizona.


There is nothing here.

Links / Videos

The imugr link, as promised. The album contains 5 images, all of the main PCB. Various components are singled out, but were not included due to word limits.