The 6502A is a microprocessor. Manufactured by Mostek, the 6502A was nearly identical to its predecessor the more famous 6502; however, while the 6502 was specced to run at 1 MHz, the 6502A was specced to run at 2 MHz (or to run with better timing margins and cooler at 1 MHz). This caused some problems introducing the chip into designs which had originated using the 6502; although the processor itself would function fine, code that relied on timing loops needed to be careful which CPU functions they were tying into. This was mostly an issue with the Apple //e.
It was used in many famous microcomputers in the late 1970s and early 1980s. Among them are the following:
- Atari 400 (released in 1979 for ~$500 US)
- Apple III (released in 1980 for $3,500; plagued with technical problems unrelated to the processor, but re-released later on with a 6502B)
- Acorn BBC Micro (released in 1981 for £300 or £500 depending on model; had EcoNet, a very early networking technology included)
- Commodore VIC-20 (released in 1981 for $300; popular entry-level computer with cartridge slot)
- Acorn Electron (released in 1983 for £200)
- Apple //e (released in 1983 for $1395, one of Apple Computer's largest sellers prior to the Macintosh)