Computer History: DEC PDP-11 CPUs and Architecture
142In this computer history episode I delve in the timeline of processors released by Digital (DEC) for the PDP-11 computer. I also spend some time talking about the different data bus types as well as the internal architecture (and performance) of the processors.
The PDP-11 architecture was quite ahead of its time when it appeared in early 1970s. The processors were popular before 8 bit bytes was a common data unit and before hexadecimal was the go to number representation in computing (DEC still used octal numbers at the time). While initially they could only see 64Kb of memory towards the end of it is life time, PDP-11 could access 4Mb of memory. Using memory mapped IO was also quite ahead of its time as well.
0:29 1972 - KA11
1:45 1975 - LSI-11
2:42 UNIBUS vs QBUS
4:15 1979 - F11
4:42 1983 - J11
5:23 Architecture and Performance
Photo credits:
http://gunkies.org/wiki/PDP-11/20
http://gunkies.org/wiki/KA11_CPU
http://www.psych.usyd.edu.au/pdp-11/table.html
http://www.psych.usyd.edu.au/pdp-11/models.html
http://www.corestore.org/1120.htm
QBUS: http://gunkies.org/wiki/QBUS
ARCH: https://programmer209.wordpress.com/2011/08/03/the-pdp-11-assembly-language/
ARCH: http://pdos.csail.mit.edu/6.828/2005/readings/pdp11-40.pdf
http://www.wolfgang-houben.de/faqpdp11.htm