I have recently acquired a R65F11 IC. This IC is part of the RSC (Rockwell Single Computer) Forth system.
Rockwell Single-Chip RSC-FORTH system as implemented in the Rockwell R65F11 (40-pin) and R65F12 (64-pin) FORTH-based one-chip Microcomputers and in the Rockwell R65FR1 FORTH ROM (which I do not ahve, but the ROM dump is available on the RSC Forth page.

Circuit diagram

	R65F11 1984 datasheet
	R65F11 1987 datasheet
	Forth Mikrocomputer Low Cost Development Module R65F11

Based upon advice and work of Glitch, see also https://github.com/glitchwrks/rsc_forth and

Rockwell R65F11 FORTH Chip