13 Nov
2011
13 Nov
'11
1:56 p.m.
On 11/13/2011 1:01 PM, ben wrote:
On 11/13/2011 1:26 PM, Eric Smith wrote:
Classic computers, yes; classic technology, maybe. Implementing a PDP-xx in a
state of the art FPGA seems reasonable to discuss for me. Others may disagree, I
guess, and want to limit the technology options to 74xx or Xilinx 3000 series.
That is their option.
As to the question, 5V tolerance combined with 512Kb (64KB) on chip memory and
'mid-sized number' of macrocells are more or less mutually exclusive options.
Toss the 5V tolerance and use external translators and lots of options pop up
... Spartan3,6 series, Altera Cyclone 1,2,3,4 series are all readily available
with more than enough internal memory and logic cells.
If you really want 5V tolerance, then start looking at multi-CPLD designs
(Xilinx 95xx series, Altera 7000 series) and external SRAM.
Don
ben wrote about FPGA boards:
Remember this is the classic computer list so, being about 10 years behind is
normal
around here. What can you recommend that has 5 volt I/O, nonvolatile memory and
mid-sized number of FPGA macro cells. Something one can use to emulate a PDP
computer with up to 512Kb of memory.
Ben.
My beef is that all the low cost boards, still
needed to connected
the PC
for use. You can't burn and go.
I've got about a dozen low-cost boards from the fairly ancient Spartan 2
through the latest Spartan 6, and not a one of them doesn't have
nonvolatile memory into which you can program the configuration
bitstream. What low-cost boards have you looked at that don't have
nonvolatile memory?