gvrobert@sactoh0.UUCP (Gary V. Roberts) (11/14/88)
I am new to unix so I hope i can get this letter into the proper place before it grows stale. I recall mention of someone doing real time work saying that he could not use the MMU. I think that this is inaccurate. The person mentioned that the page MMU supported VM and this was not deterministic, the thing is, just because you have the MMU for protection does not mean that you have to support VM. It can be set up to be transparent except when the program accesses memory that is not its own ( and this requires fixing because it is a bug ). As to the MMU option, back when I was designing my own 32K system ( many years ago ), the MMU could be made removable witht the addition of one pull up and one jumper select. The reason this is possible is because ( unlike the Moto--- sol'n ) the address goes into and out of the MMU on the same pins. Although the only real o real problem I see with the MMU is the imposed wait state. BTW, if this letter seems chopped to hell, this is my first experience with vi. I would be ingterested in the news letter that I heard about. I recall someone saying that rick put out a news letter but I do not know which Rick or how I would get ahold of him. I would also appreciate any data on where I could get the latest data books and stuff ( I am a S/W type these days and do not have access to the resources I had as a H/W type ). GVRoberts -- ############################################################# # PRIVATE # Serving The State Capitol # # PARKING # Of California: sactoh0 # #############################################################