Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!samsung!usc!apple!goofy.apple.com!esmith From: esmith@goofy.apple.com (Eric Smith) Newsgroups: comp.arch Subject: Re: Looking for a really odd computer Message-ID: Date: 10 Oct 90 00:32:51 GMT References: <2721@crdos1.crd.ge.COM> <2018@inducom.UUCP> Sender: usenet@Apple.COM Organization: Frobozz Magic Widget Company Lines: 41 In-reply-to: meindert@inducom.UUCP's message of 4 Oct 90 06:54:30 GMT In article <2018@inducom.UUCP> meindert@inducom.UUCP (Meindert Kuipers) writes: > Although not odd word size, my good old HP-41 calculator has a little > CPU with 12-bit instructions. The memory space for these "assembly" > programs is completely 12 bits. The data space however has words of > 56 bits, allowing 7 bytes of data, or 10 digit precision (with exponent). Actually, it has 10-bit instructions and ROM. The instruction and data space are almost completely separate, with the exception of an instruction to allowing reading ROM words as data. That instruction was the primary architectural advance of the HP-41's processor compared to their older ones. Do HP's new calculators use the same principle? I have understood that the 10-series (HP12, HP16) use the same processor. The 10-series apparently used the same architecture, possibly with minor changes (I'm not sure). The new machines use the same basic architecture as the Saturn processor that was used in the HP-71B. Saturn had a single address space using nibble (4-bit) addressing and 5-nibble (20-bit) addressing, for a total 1 Meganibble (512K byte) address space. The processors in the current HP calculator line use essentially the same architecture with a few additional instructions. The following is a (possibly incomplete) list of the HP products that use this architecture, organized by category: Handheld computers: HP-71B Business calculators: HP-10B, HP-14B, HP-17B, HP-17BII, HP-18C, HP-19B, HP-19BII Scientific calculators: HP-20S, HP-21S, HP-22S, HP-27S, HP-28C, HP-28S, HP-32S, HP-42S, HP-48SX Eric -- Eric L. Smith Opinions expressed herein do not necessarily reflect those esmith@apple.com of my employer, friends, family, computer, or even me! :-)