Synertek 6530-004 RRIOT from the 35th week of 1979.
RRIOT stands for RAM ROM Input Output Timer, a combination chip with everything but the CPU crammed in there. It's not high-performance, but it's a compact companion to a 6502. The -004 suffix indicates that the ROM contains the Terminal Interface Monitor on board. It only has 64 bytes of RAM on board, so more is typically suggested to do anything of consequence, but it makes up for that by having a pair of 8-bit bidirectional data ports, and internal timers to setup interrupts.















