Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!cornell!uw-beaver!ubc-cs!alberta!calgary!ctycal!ingoldsb From: ingoldsb@ctycal.COM (Terry Ingoldsby) Newsgroups: comp.sys.m6809 Subject: Re: Funny key presses Summary: 6809 speed Message-ID: <433@ctycal.UUCP> Date: 17 Aug 89 19:12:26 GMT References: <430@ctycal.UUCP> Organization: The City of Calgary, Ab Lines: 23 In article <430@ctycal.UUCP>, ingoldsb@ctycal.COM (Terry Ingoldsby) writes: > Has anyone fixed the keyboard driver for COCO3 OS9 Level II? The My apologies, that was supposed to go to comp.os.os9. I know that there are some higher speed versions of the 6809 available. Does anyone know if these are just fast clock speed versions of the ordinary MC6809, or do they reduce the number of cycles for the longer instructions. The former is not desirable in many cases since memory has to be faster to keep up with the chip. Since many implementations do the memory access in half a cycle, this can put quite a load on memory components (ie. they have to be fast). In some of the longer 6809 instructions memory lies idle. A fast clocked 6809 will require fast memory that does nothing part of the time. Not an efficient use of resources! On the other hand, making instructions that spend a lot of their time doing things internally (not using the external buses) faster would allow direct replacement of existing 6809s. I think this was done with 8088s. -- Terry Ingoldsby ctycal!ingoldsb@calgary.UUCP Land Information Systems or The City of Calgary ...{alberta,ubc-cs,utai}!calgary!ctycal!ingoldsb