Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!seismo!rutgers!ames!ucbcad!ucbvax!cbatt!ihnp4!ihwpt!knudsen From: knudsen@ihwpt.UUCP (mike knudsen) Newsgroups: comp.sys.m6809 Subject: More on MultiPak Upgrades (CocoIII) Message-ID: <1302@ihwpt.UUCP> Date: Mon, 15-Dec-86 13:43:12 EST Article-I.D.: ihwpt.1302 Posted: Mon Dec 15 13:43:12 1986 Date-Received: Tue, 16-Dec-86 22:46:58 EST Distribution: net Organization: AT&T Bell Labs, Naperville, IL Lines: 38 (coco3 bugs for the line eater) The latest (Jan 87) RAINBOW has quite a good article on upgrading MultiPak Interfaces (MPIs, toasters) for the Coco III. It shoots down some notions that some of us have had. Points made are: (1) The old gray MPIs, plus some rugged white ones with the same guts, need only a PAL replacement. The later white ones were a cost-reduced design that needs a satellite board to fix. Yes, Jim O., the old ones ARE better! Detailed instructions are given to install the satellite board yourself (it ain't trivial!). (2a) No matter how well your MPI seems to work with CocoIII, you had better get it upgraded to avoid subtle (?) future problems. Thus saith the gods at Fort Worth. (2b) You need the upgrade even tho you don't install 512K RAM. Rumor had it that 128K operation was OK w/out upgrading the MPI. (3) The upgrade not only busts the ghost at FF9F (of the MPI control reg at FF7F) but also "locks out" addresses FF80 and up (I guess by witholding the E and Q clocks). This is to avoid bus conflicts with the GIME's regs. (WHY lock out FF80~8F? Not used by GIME. Yet.) (4) Due to (3), your upgraded MPI will no longer work with CocoMax, WordPak, etc etc EVEN ON A COCO I or II. So the article tells how to hack a switch into your toaster to disable the upgrade (degrade? retrograde?). What I'd like is to always keep the ghost disabled but select the FF80 mode. Probably not possible with the PAL upgrade. (5) Article gives part numbers for ordering the PAL or satellite board from RS National Parts. Happy hacking, mike k