Re: [GTALUG] "Golden Age for Computer Architecture"

On 08/12/2018 01:26 PM, Russell Reiter via talk wrote:

Some wag deemed it a "ring 4" exploit.

Many years ago, I was a computer tech, working on a variety of systems, including the VAX 11/780 and Data General Eclipse.  Both of those had a writable control store and the VAX even loaded it's microcode from a floppy at boot.  One ot the things I had to do, when repairing Eclipse computers was work my way through the microcode, using a very large listing and a logic probe, along with the microstep switch on the front panel.  The Eclipse used 4 AMD 4 bit slice processors and, IIRC, over 100 bits wide ROM to contain the instruction set.  With the WCS, I expect it would be fairly easy to insert malware.