Self modifying code, lambda calculus - Re: ENIAC programming

Dave G4UGM dave.g4ugm at
Fri Sep 18 08:43:27 CDT 2015

> -----Original Message-----
> From: cctalk [mailto:cctalk-bounces at] On Behalf Of tony
> Sent: 18 September 2015 14:33
> To: General Discussion: On-Topic and Off-Topic Posts
> <cctalk at>
> Subject: RE: Self modifying code, lambda calculus - Re: ENIAC programming
> >
> > > Are there any computers that do let you put microcode into RAM
> > > now-days.
> >

Of course not sure if it's a stage further or a stage less, but any way, but
for any FPGA implementation of a computer, and there are many about, then
the entire system definition is stored in RAM which is loaded at power-on...

> > "Now-days"?  There are some that do that, some of which are still in
> > operational shape.  Some VAXen, in particular, have something called
> > "writable control store", which is essentially microcode RAM.
> As far as I know, the VAX11/730 (There is one next to me waiting for me to
> have time to restore it) has the microcode entirely in RAM. Classic PERQs
(3 in
> the next room) have their microcode entirely in RAM too (in that case,
> is a microcode boot ROM to load the microcode from disk, but it is
> out after the microcode is loaded).
> -tony

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