Harvard v. von Neumann
ploopster at gmail.com
Fri Dec 12 18:13:57 CST 2008
Chuck Guzis wrote:
> On 12 Dec 2008 at 18:41, Sridhar Ayengar wrote:
>> But, the data could only be operated on from the stack, right? So, if
>> you wanted to write a self-modifying program, wouldn't you need to have
>> two entries in the PRT, similarly to what you've suggested, and then
>> wouldn't you also need to push the elements of the array containing the
>> program data onto the stack, operate on them, then pop them off the
>> stack and back into the array space, thereby allowing the code to run?
>> Or am I missing something?
> I think we're saying the same thing. In other words, code
> modification was certainly possible.
But they threw up roadblocks to try to prevent it, right? It sure looks
like the array storage out-of-stack seemed to have been tacked onto the
architecture as an afterthought.
More information about the cctalk