microcoding a PC into a PDP-11 (was: RE: Classic Computers vs. Classic Computing)

From: Chuck McManis <cmcmanis_at_netapp.com>
Date: Tue Sep 18 11:53:41 2001

>Very good point. I was thinking that it would be nice to have a machine that
>was a PDP-11 as soon as you flipped on the power, but probably not worth the
>cost and hassle of the flash. Didn't some of the VAXen boot their microcode
>from a floppy?

Yes, the VAX 11/780 does.

Actually a more compelling idea for me would be to reverse engineer the
processor on a modern disk drive (like a SCSI drive) and then reprogram the
disk controller boards firmware such that the disk thought it was a PDP-11.
It would be fairly straight forward (but certainly not trivial) to
construct a communication protocol for this.

Interestingly, the DEC DSSI drives are nearly already "there" when it comes
to this sort of scenario. There already is a communications protocol that
lets you "log in" to the drive and talk to a variety of programs that are
stored in the Disk drives flash. It may actually have a real PDP-11 on it,
I don't know who might know what all the parts are on a DSSI drive.

--Chuck
Received on Tue Sep 18 2001 - 11:53:41 BST