How CPU's work (was Re: Hi, I'm new...)

On 8/6/2006 at 10:39 AM Don wrote: ...and that's really the nub of my argument. I have no quibble with the application of an MPU to play MP3s, run a scanner or traffic signal, but the huge mistake IMOHO, was trying to turn them into "Gemeral Purpose Computers". I'm not proposing that large-scale integration was wrong--it alone would reduce the size of your "washing machine" to a deskop box. Heck, my mouse has a PIC in it--but I'm not about to try to put a word processor or a DBMS on it. We're still living with the legacy of the 8080 and CP/M in Windows. Not your post, but Dave's. While it's true that there were a significant number of major differences between the 8008 and the 8080, the architecture registers; H,L handled as a pair to address memory; basic instruction layout, etc. The addion of SP and 16-bit addressing was a welcome addition, as were 16 bit adds and loads and 256 I/O ports, but to my eye, the 8080 looked like a tarted-up 8008. One valuable aspect of the 8008 lost was the treatment of 00 and FF as HALT instructions. Also, I'm not saying that the CP1600 was a speed demon--AFAIK, aside fromt he Activision games, it found no general application. Yet, from a programming standpoint, the closest thing to it prior to the 68000 was the LSI-11 (not a speed demon either). Sometimes, the actions of the people inside the micro business made me wonder. When I put my first hard disk (a 14-inch Shugart) on an 8085, I noticed that there was no one offering disk backup utilities for micros. I still have the rejection letter (along with the 8" floppy) from Lifeboat saying that they didn't think there was any market for a hard disk backup package. What I found incredible was the reinvention of mistakes. How long was it before the micro database people realized that atomic logging of database operations was worse than useless--that one had to log entire transactions? Mainframe people knew that before there were even micros. Cheers, Chuck