This manual relates to the MOS 6509 used in many Commodore products. The big brother to the 6502 (used in the Commodore PET) was used in Commodore 64 and the B-Series / CBM-II line among others. This manual is from October of 1986. General information on all of the 650x line is available HERE.
“The 6509 is a low-cost microprocessor capable of solving a broad range of small-systems and memory management problems at minimum cost to the user. A memory management system allows for up to One Mega-Byte of memory of ease in down loading languages, operating systems or other data.
The Three-State sixteen-bit Address Bus allows Direct Memory Accessing (DMA) and multi-processor systems sharing a common memory while the Four-bit Extended Address Register allows for up to a one Mega-Byte of data storage. The internal processor architecture is identical to the Commodore Semiconductor Group 6502 to provide software compatibility.”
This graphics below were converted from a large .PDF on Richard Cini’s excellent site which is defunct in 2018 so we have linked Archive.org copy of it. This was reproduced October 17, 2002 with permission granted in July of 2002.
Thanx again Richard!