FPGA VAX update

[Brian Wheeler]

On Wed, 2005-11-02 at 14:16 -0500, Sridhar Ayengar wrote:
> der Mouse wrote:
> >>>I guess nobody even considers building a computer from scratch. :(
> >>
> >>[...]
> >>Wasn't there an article a looong time ago about a fellow who built
> >>his own CPU from TTL parts in BYTE or Microcomputing?
> > 
> > 
> > I dunno about that, but I once did just that.  I took a digital
> > hardware design course, and as a term project I breadboarded a little
> > 4-bit computer.  (I think the whole class did likewise, but it was long
> > enough ago that memory is fuzzy.)  Only 16 words of memory, and 4-bit
> > words at that, with 4-bit opcodes - not a terribly powerful machine,
> > but an extremely instructive one to build.  All TTL; the most
> > complicated building block was a 4-bit ALU chip, a 74181 I think.
> 
> We had to do something similar in our hardware design course.  We had a 
> choice.  We could actually etch boards and solder sockets, breadboard it 
> or simulate it.  We had sixteen banks of sixteen locations, four bits 
> each.  And we didn't have branch instructions.  Only relative jumps.
> 
> Most (all but 5?) students simulated it.  I breadboarded.  (I hadn't yet 
> learned soldering then.)  One guy soldered it.  Probably made a pretty 
> good souvenir.
> 
> Peace...  Sridhar

I took a hardware class where we (each team of 2 students) had to build
a PDP-8 using PALs, some 74xx chips, a bit of Static RAM, and a ton of
wire wrapping.  The final exam consisted of the instructor breaking each
machine in 5 different ways and we 3 hours to fix it.  That was a pretty
cool class.

I hear they use FPGAs now in the class...kids these days.

Brian