On May 22, 2009, at 12:45 AM, bfranchuk at
jetnet.ab.ca wrote:
What
sort of density are you looking for? I've seen some really
nice 16Kx1 SRAM chips made by Inmos. Or you could implement a DRAM
controller in your FPGA and do it that way, with 1-bit-wide DRAM chips.
I am looking at about 32K 18 bit word memory on small single board
computer, some thing around the size of a PDP 8/e in functionality but
18 rather than 12 bits.
I am looking to add modern features (1968 ish) like character addressable
memory, Stack and Index registers as well as # data.
Memory, Uart and CPU I can get on one PCB as well as simple IDE
interface.
The other PCB will be the 18 bit front panel with the MAR,MBR and AC
displayed
connected via ribbon cable.
Ben.
-Dave
Ps.
Since this is a small computer, hardware support of floating point is
NOT a
option. :)
You could probably interface something like an 8087 to that. Their
architecture is actually kinda nice, IMO.
Unlikely , but the 8087 sold a lot PC's. I have Knuth's books so I can at
least write some floating point software. Ben.