bass@dmsd.UUCP (John Bass) (09/23/86)
It would be nice if SUN would post exactly what they claim to patent, or else someone who has the time/interest could visit the Patent Library in the Bay area to get and post a copy of the patent description. The SUN readers have been amazingly quite thru this whole discussion, did they get a gag order from management? I do know that the Onix C8002 (designed 1979, shipped 1980), Tandy Model 16 (designed 1981 (1982?), shipped 1982), and Fortune 32:16 (designed 1981, shipped 1982) all use RAS from the low address lines. The Tandy and Fortune seem to overlap mmu translation with ras prior to cas, it is unclear what the ONIX does. All three systems have published schematics and hardware reference manuals, Tandy's can be purchased over the counter without any trouble, Fortune requires a developers agreement, and I don't know what the status of the ONIX manual is now days -- it used to be available with little trouble. The Onix mmu is based on mapping rams with 2k pages, the Tandy and Fortune use base/limit mmu's. I know of several multiuser Z80 designs with bank switched memory that use nearly identical technology (RAS from low address lines, CAS from high address lines and bank register) all dating back to the mid/late 70's. These could hardly claim to overlap anything since the bank address is a static latch. Anybody know of a design based on mapping rams or register files? Unless SUN is claiming much more than RAS/CAS overlap, it would be nice if they abandoned the patent voluntarily and save everyone the legal fees to formally contest and defeat it. How about it you guys at SUN?? Do you really claim more than this?? -- John Bass (DBA:DMS Design) DMS Design (System Design, Performance and Arch Consultants) {amdahl,fortune,polyslo}!dmsd!bass