Harvard vs. vonNeumanZ

[Tom Jennings]

On Tue, 28 Sep 2004, Roger Merchberger wrote:

> If you consider MERGEing different basic programs (if you MERGE in a new
> program where line numbers match, most basics that I'd worked with  would
> replace the original statement with the new... if you count that, it was
> rather common in the CoCo world.

BASIC "code" is data, interpreted by an interpreter program,
so this does not count as self-modifying in a global sort of way.

In fact the whole idea of self-modifying and to a limited extent,
stored-program is somewhat slippery.

Non-stored-program computers, like the old Harvard relay
calculators and new Microchip Inc's PICs, can however simulate
a stored-program computer, by having the fixed, unchanging
program be an interpreter for a scheme that is, in effect,
stored-program. This isn't very amazing or even notable, since
"real" stored-program computers are made out of dumb things like
transistors or even tubes, so making one out of a Harvard arch
"computer" is only a subset.