blarson@oberon.UUCP (Bob Larson) (12/21/85)
The 6829 is an MMU designed for use with the 6809 and 6809E. It maps the 64k byte addressing range of a 6809 into 32 2k byte pages in a 2 megabyte physical memory. Each 6829 handles 4 tasks, up to 8 may be used in a system. (One task is dedicated to interupt handling, and another to DMA if any. The number of tasks handled in hardware does not limit the number of tasks in software.) Acording to the "Os9 Level Two System Designers Guide" (by Microware) two 6829's are needed by Os9 Level II, and more are unused. The major problem with the 6829 is its lack of speed. This publication also gave some hints on discrete MMU design for Os9 Level II. (Microware gave this 13 page booklet out at the os9 seminar-- I don't know if they normaly charge for it or not.) -- Bob Larson Arpa: Blarson@Usc-Ecl.Arpa Uucp: ihnp4!sdcrdcf!oberon!blarson __________________________________ Unix: An operating system similar to Os-9, but with less functionality and special features designed to soak up excess memory, disk space and CPU time on large, expencive computers. -- Os-9/68000 operating system users manual