"GTR" <noone@xxxxxxxxxxx> schreef in bericht
> I'm a newbie whose been playing around with miscellaneous circuits using
> chips. Now, as a learning experience, I want to attempt to build a small
> computer around the 6809 processor. I am curious if anyone can recommend a
> RAM chip for this project with the following characteristics:
> a) Just needs 5 V supply.
> b) Can interface with TTL chips and has similar leg spacing(so I can
> breadboard it)
> c) Common enough I have a good chance at finding it at a reasonably
> electronics store.
> I had considered using the 4164, are there other better alternatives?
> Perhaps a chip that meets the above criteria and has 16 bit addressing in
> single pass, I believe the 4164 needs the low 8 bits of the address,
> latched, then the high 8 bits of the 16 bit address.
Use SRAM. Conrad offers 6264 (8kx8 100ns) for about ?4, the 62256 (32kx8
100ns) for about ?5 and the 681000 (128kx8 100ns) for about ?10. The latter
fills the addressspace of the old 6809 twice. The same amount of DRAM will
hardly be cheaper (maybe even more expensive) and much harder to implement.