Ma Be (Marcus Berger) wrote in USMA 17256 >On Sat, 5 Jan 2002 18:02:52 > M R wrote: >... >>The guy who maintains this website should be >>anti-metric. If you go little above in the webpage, >>he argues that computers have defied metric system. >> >>Madan >>... >Actually the above is a cheap excuse. Unfortunately the problem here is >that these guys decided to build computers using a binary number of bits, >i.e. 4 bits, 8 bits, 16 bits, 32 bits, etc (AARRGHH!!). Had they been >more user-friendly to the decimal system and they would have created >10-bit, 20-bit, 30-bit, etc computers, alas! IMHO there is no reasonable >justification to use binary powers for bit buses. What can I say?... :-S > >Marcus
I suspect that Marcus confuses digit length and word length. A decimal digit requires 4 binary digits or bits. Word length can be anything from 8 bits in the IBM 1408 and 1410 up to 64 bits in the last Control Data computer. The Control Data 6600 had a 60-bit word. However, Marcus has a point. In the early days of computers there were several decimal computers. They included the IBM 705 and 650, the Datatron that was bought out by Burroughs, and a Britrish Tabulating Machine computer that could work with pounds, shillings and pence. The IBM 650 worked on decimal digits, each of which had to contain 2 one-bits and 3 zero-bits. This system checked every digit. The Datatron used 4-bit digits; 1010, 1011, 1100, 1101, 1110, and 1111 were illegal and would stop the computer. This gave weaker checking than the IBM 650 system. The IBM 360 and 370 can operate in either the hexadecimal or decimal mode. However, the basic electronics of all computers are binary, and most use programming to achieve decimal arithmetic. Joseph B.Reid 17 Glebe Road West Toronto M5P 1C8 TEL. 416-486-6071
