From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me X-Spam-Level: X-Spam-Status: No, score=-1.3 required=5.0 tests=BAYES_00,INVALID_MSGID autolearn=no autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 103376,45a9122ddf5fcf5 X-Google-Attributes: gid103376,public From: kilgallen@eisner.decus.org (Larry Kilgallen) Subject: Re: Rules for Representation of Subtypes Date: 1996/10/01 Message-ID: <1996Oct1.125614.1@eisner>#1/1 X-Deja-AN: 186496478 x-nntp-posting-host: eisner.decus.org references: <52oi3v$din@mill.gdls.com> x-nntp-posting-user: KILGALLEN x-trace: 844188978/26899 organization: LJK Software newsgroups: comp.lang.ada Date: 1996-10-01T00:00:00+00:00 List-Id: In article <52oi3v$din@mill.gdls.com>, schwarza@gdls.com (Art Schwarz) writes: > Nearest that I can remember, byte size varies by machine. It is NOT an > eight byte quantity. This is probably the motivation to use _octet_ > instead of bytes in formal descriptions. > > An example of byte sizes: CDC 1604 6 bits > CDC 6000 12 bits > PC 8 bits > UNIVAC 1100 7, 8, 9, 12 bits > PDP-10 7 bits (and others?) The PDP-10 could handle any byte size from 1 to 35 (36 also worked in hardware, but was a degenerate case, since it was the fullword). Sizes which were popular in software included 6 and 7, providing 6 and 5 bytes per fullword. In the case of 7 bit bytes, there was one bit left over per fullword, and there were cases where that bit was used for some purpose. Now I am not predicting that the PDP-10 instruction set will make a big comeback, but having seen the PDP-10 and the Alpha, I am certainly not going to claim the ability to predict the nature of computer hardware thirty years hence. Several programming languages have survived 30 years, so whatever that future hardware looks like, Ada programmers should be ready for it. Will the demand for Unicode support make 16 bits the typical size of a Storage Unit ? Or will egalitarian support for those Korean dialects drive it to 32 bits ? Larry Kilgallen