On Fri, 5 Feb 2016 14:00:29 -0600, Elardus Engelbrecht wrote: >8 bit MOS Technology 6510 with 64KB memory - Loosely based on Motorola AFAIK.
Depends on what you mean by "based on". The 6502 was designed by some of the same people who designed the 6800 at Motorola, but it was a rather different design. The 6501 and 6502 were designed concurrently. The 6501 was pin-compatible with the 6800 and, like the 6800, required a two-phase clock input. The idea was that the 6501 could be plugged into an existing circuit board designed for the 6800. The instruction set and the internal architecture were different, though, so they couldn't run the same software. The 6502 has an on-chip two-phase clock generator, simplifying system design. The 6501 and 6502 were also quite inexpensive, compared to other processors of the time. The price for the 6502 was $25 for one. MOS Technology produced the KIM-1 (Keyboard Input Monitor) evaluation board for the 6502. It included a 6 digit,7-segment LED display, and a hex keypad, as well as a teletype interface and an audio cassette interface for storing and retrieving data. It had 2K of ROM with code to operate all of that, and 1K + 128 bytes of RAM. I bought mine in the spring of 1976, just a couple of months before the announcement of the Apple-1. I expanded the KIM-1 with an additional 24K of memory, as well as a video interface. I also bought an early Shugart Technology 5MB 5 1/4 inch hard drive for it. That was before Shugart Associates sued Al Shugart over the use of his name, and Shugart Technology changed their name to Seagate. When I bought my second computer, an Atari 800, I was working on a dual port memory card for it so that the KIM-1 could access the hard drive and the drive could access memory directly without slowing down the processor. The Atari was intended as my travel machine. I worked for Amdahl at the time and was on the road all the time. I packed the Atari in some cheap luggage and took it with me as checked baggage on hundreds of flights. No doubt it suffered a lot of abuse, but it never failed. What does this have to do with mainframes? Nothing. -- Tom Marchant ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
