AW: When did Memory- and IO Protection Emerge (Esp. in Minis)?

Jay West jwest at
Wed May 4 16:02:59 CDT 2016

Marc wrote...
My 1974 HP 21MX, descendant of the HP 2100A, sure inherited this Memory Protect card. One register that you load, prevents access to any memory below the address of the register.
That's just the fence register (memory access interception) capability. There's also the I/O & HLT instruction interception, interrupt interception,  etc. mentioned earlier.

M.E.M. was standard option (ie. Included) with most E/F machines.

I don't know if the 2114/5/6 had the same capabilities in the fence area....


More information about the cctalk mailing list