Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!helios!bcm!dimacs.rutgers.edu!seismo!uunet!zephyr.ens.tek.com!uw-beaver!cornell!rochester!pt.cs.cmu.edu!o.gp.cs.cmu.edu!andrew.cmu.edu!ww0n+ From: ww0n+@andrew.cmu.edu (Walter Lloyd Wimer III) Newsgroups: comp.sys.m6809 Subject: Re: COCO upgrade Message-ID: Date: 6 Feb 91 20:16:25 GMT References: , <1991Feb5.005957.14282@wlbr.imsd.contel.com> Organization: Network Development, Carnegie Mellon, Pittsburgh, PA Lines: 35 In-Reply-To: <1991Feb5.005957.14282@wlbr.imsd.contel.com> pete@wlbr.imsd.contel.com.UUCP (Pete Lyall) writes: > In article rh2y+@andrew.cmu.edu > (Russell E. Hoffman, II) writes: > >Gilbert M. Sterart writes: > > > >>[paraphrased] .. I have a CoCo I, I wanna replace > >>it with a CoCo III, what can I keep / what can I throw away... > The larger problem is that running OS9 LII, you're running at 1.78 Mhz > (similar to the old coco's high speed mode), and this causes problems > with older controllers. Some folks have patched their disk driver code > so that any disk access are done at the older .89 Mhz rate. Newer > controllers, andmost of the J&M family seem to have been unaffected by > the speed changes. > Pete Lyall An even larger problem is that the original Radio Shack floppy controllers required +12 volts which is not available on the CoCo 3. When I got my CoCo 3, I hacked my controller, cable, and drive to get the +12 volts from the floppy drive. Crude, but it worked fine. And my controller didn't seem to have any problem with the CoCo 3's 1.78 MHz clock rate. Now I have an FHL Eliminator, so I no longer use my RS controller on my CoCo 3. I may resurrect my CoCo I and then I'll need the RS controller again. Walt Wimer Carnegie Mellon University