jjb@sequent.UUCP (Jeff Bob Berkowitz) (08/03/88)
In article <753@applix.UUCP>, scott@applix.UUCP (Scott Evernden) writes: > > My Cosmac-clone (anyone remember the BYTE ads for the Quest ELF?) was > one of the funnest toys I ever had. 16 absolutely general-purpose > 16bit registers, etc. etc... > > -scott The 1802 was an important achievement. Its strange architecture was clearly imposed by the requirement of packing an entire CPU on a single chip using mid-1970's CMOS technology (10 micron lines? - can anyone correct me?). RCA data books from that era listed an earlier device, the 1801, which was split across two chips. Was the 1801 ever produced? Rumor has it that parts of the instruction set - in particular, autoincrement addressing - were much more "sensible" until DEC threatened to sue for infringement on the PDP-11 design. Is there any truth to this? Chrysler used the device in the difficult "under-the-hood" environment for years - true? For many years, the 1802 was the ONLY choice for a wide variety of specialized applications requiring low power, high noise immunity, and so on. It was also extremely simple to apply. In general, a "technology to fit the times" - also, the only processor with a SEX instruction ("SEt X", yes it's true :-). -- Jeff Berkowitz N6QOM {sun,tektronix}!sequent!jjb Sequent Computer Systems Custom Systems Group 15450 SW Koll Pkwy Home (503)629-0806 Beaverton OR 97006 Work (503)526-4148
aal@romeo.cs.duke.edu (Anselmo A. Lastra) (08/04/88)
There was a two chip COSMAC. The early development systems from RCA used the two chips. The move to one chip was driven by the fact that the 1802 was targeted to controller applications. They expected a large part of their market to be automotive control. Another CMOS micro of that era was from Intersil (the 6100?). It used the PDP-8 architecture.
friedl@vsi.UUCP (Stephen J. Friedl) (08/04/88)
In article <3884@sequent.UUCP>, jjb@sequent.UUCP (Jeff Bob Berkowitz) writes: > For many years, the 1802 was the ONLY choice for a wide variety of specialized > applications requiring low power, high noise immunity, and so on. It was > also extremely simple to apply. In general, a "technology to fit the times" - > also, the only processor with a SEX instruction ("SEt X", yes it's true :-). The 1802 was a wonderful chip. One of the electronics rags ran a great series on building the COSMAC ELF written by the designer of the chip, Joe Weisbecker (I think). It had on-chip DMA (used for hand-loading a program), and because the guts were all static CMOS, the clock was DC to around 2 MHz - try that with your Z80 (single-step was trivial). If you want an easy first processor design, use the 1802. Another thing: in the early 1980s, CMOS meant "low power" much more than it does now, and the 1802 was the only guy on the block in CMOS. Back then, I worked for a company (Telxon) that designed small portable data entry terminals, and for many years the 1802 was indeed the only choice for this application. I even heard a rumor than in around 1981 (or so), more 1802s were sold than any other 8-bit processor. Because these things are hidden away in litte black boxes, they aren't so well known outside the microcontroller industry. It's been a long time on this info -- anybody got any corrections? Steve -- Steve Friedl V-Systems, Inc. +1 714 545 6442 3B2-kind-of-guy friedl@vsi.com {backbones}!vsi.com!friedl attmail!vsi!friedl --------- Nancy Reagan on flood-control: "Just say Noah"-----------
jejones@mcrware.UUCP (James Jones) (08/04/88)
In article <3884@sequent.UUCP>, jjb@sequent.UUCP (Jeff Bob Berkowitz) writes: > For many years, the 1802 was the ONLY choice for a wide variety of specialized > applications .... > also, the only processor with a SEX instruction ("SEt X", yes it's true :-). I respectfully differ. The 6809 has a SEX instruction ("Sign EXtend", i.e. propagate the MSB of the B register into the A register giving a 16-bit quantity in the double accumulator D.) :-) Cheers, James Jones
markf@amc.UUCP (Mark Freeman) (08/04/88)
In article <3884@sequent.UUCP>, jjb@sequent.UUCP (Jeff Bob Berkowitz) writes: > RCA > data books from that era listed an earlier device, the 1801, which was split > across two chips. Was the 1801 ever produced? Yes -- I recall using one of the two chips (the register chip) in some experimental circuit. The 1802 came out shortly thereafter, and I threw it out. -- Mark S. Freeman Applied Microsystems Corp. markf@amc
elg@killer.DALLAS.TX.US (Eric Green) (08/07/88)
In message <3884@sequent.UUCP>, jjb@sequent.UUCP (Jeff Bob Berkowitz) says: >For many years, the 1802 was the ONLY choice for a wide variety of specialized >applications requiring low power, high noise immunity, and so on. It was >also extremely simple to apply. In general, a "technology to fit the times" - >also, the only processor with a SEX instruction ("SEt X", yes it's true :-). > Actually, the 6809 has a SEX instruction, too (Sign extend .X register). OF course, the 6809 was also 6 or 7 years later... I don't know if the original 6800 had SEX, alas, maybe someone a bit more, err, ancient, than I, can fill us in on that. -- Eric Lee Green ..!{ames,decwrl,mit-eddie,osu-cis}!killer!elg Snail Mail P.O. Box 92191 Lafayette, LA 70509 MISFORTUNE, n. The kind of fortune that never misses.
jsnow@esunix.UUCP (John Snow) (08/07/88)
From article <3884@sequent.UUCP>, by jjb@sequent.UUCP (Jeff Bob Berkowitz): > For many years, the 1802 was the ONLY choice for a wide variety of specialized > applications requiring low power, high noise immunity, and so on. It was > also extremely simple to apply. In general, a "technology to fit the times" - > also, the only processor with a SEX instruction ("SEt X", yes it's true :-). The Motorola 6809 also has a SEX instruction (Sign Extend). -- ----------------------------------------------------------------------------- John F. Snow UUCP: {ihnp4,decvax}!decwrl!esunix!jsnow Evans & Sutherland Computer Corp. Compuserve: 71550,1152 BIX: johnfsnow Salt Lake City, Utah
mills@baloo.eng.ohio-state.edu (Christopher Mills) (08/08/88)
In article <5109@killer.DALLAS.TX.US> writes: > >Actually, the 6809 has a SEX instruction, too (Sign extend .X >register). >-- >Eric Lee Green ..!{ames,decwrl,mit-eddie,osu-cis}!killer!elg > Snail Mail P.O. Box 92191 Lafayette, LA 70509 > MISFORTUNE, n. The kind of fortune that never misses. Actually, it sign extends the B register into the A register. Just call me Mr Accuracy. -=- _________________________________________________________________________ | Christopher Mills | "If you see someone without a smile, | | mills@baloo.eng.ohio-state.edu | give them mine - I'm not using it." | ====== My thoughts are not my own--I'm posessed by mailer daemons. ======
daver@hcx2.SSD.HARRIS.COM (08/12/88)
>> ... the 1802 ... >> ... the only processor with a SEX instruction ("SEt X", yes it's true :-). > >The Motorola 6809 also has a SEX instruction (Sign Extend). Add the Harris H-800 SEX instruction (Square X Register). Hmmm.. Why not SQX?