25 Apr
2013
25 Apr
'13
4:01 p.m.
On Wednesday, April 24, 2013 19:27:34 Jim Stephens wrote:
Thanks for the info, Dave. I'm also puzzling over
what to get and what
to do with it.
A friend looked at the PDP2011 page and the two main choices, and I had
(and still mostly have) myself convinced that the DE0 board is the way
to go. I'm only looking at that, and perhaps the 9020 processor that
Lawrence Wilkinson has done as another thing to try to run on it.
however he suggested this board which is a lot more expensive (about
400) but has a lot more to the chip.
http://www.digilentinc.com/Products/Detail.cfm?NavPath=2,400,1028&Prod=…
ARD
DE0 is a nice little board, and it will run my pdp11 stuff - with some
limitations; for the big cpu models, the floating point unit will not fit in.
There are bigger models, like de2-115 - but that's significantly more
expensive, and de0-nano - which is rather minimalistic, and will require some
wiring or soldering. Altera is apparently also coming with a new low-priced
cyclone-5 based board somewhat comparable with zedboard - ie, an fpga with an
arm core in it.
Nexys2 exists in two variants - be sure to get the bigger -1200 version if you
go that way, the -500 will be too small for many things in my pdp11 - although
you can still squeeze a small system in. The other Digilent boards are IMO
either a bit oldish (ie, the spartan-3 boards), or too expensive (atlys etc),
or not really big enough (nexys3) - and I also don't like that some boards
require you to use Digilent's tools, and those only work on Windows.
Zedboard, btw, looks like it is a complicated beast - and much more than
required for a mere pdp11. Also, it has ddr3 memory - currently, I only have
static ram or regular sdram drivers in my vhdl, and ddr3 might be a bit more
complicated.
And that's a thing to consider as well if you want to use the boards for other
things besides my pdp11 :-) as memory drivers might be a lot of work to fit
onto an existing design.