About Gilmore's letter on IBM&Intel push copy protection into ordinary disk drives

[Neil Johnson]

> In message <20001224150321.A24733 at die.com>, Dave Emery writes:
> >
> >
> > A note on this note - I was told back in that era by Sun field
> >service people that the standard thing to do when a motherboard failed
> >was to swap the ID prom from the old motherboard onto the new one, thus
> >avoiding the whole license conversion problem in the first place (but of
> >course also  doing wonders for the ability to track specific pieces of
> >hardware and document ECO levels and the like, since a significant number
> >of motherboards had swapped ID proms in which all the other information
> >in the prom didn't match the actual board).
>
> "Standard"?  It was more than that; it was the *right* thing to do.  On
> a diskless workstation, there was no other identity to the machine; if
> you didn't swap the ID prom -- which was used for the low-order 24 bits
> of the Ethernet address -- your machine wouldn't receive the proper
> boot image, etc.  Add to that the number of machines in the mid-to-late
> 80's that didn't have ARP, and it was utterly necessary.
>
>
> --Steve Bellovin

Same was true of DEC workstations. The service tech would switch the proms.
The board had it's own serial number label on the board so they could still
keep track of it.