18 Apr
2001
18 Apr
'01
7:16 p.m.
From: Ethan Dicks <ethan_dicks(a)yahoo.com>
It's
> now i just need the RAM that the schematics
have....i believe that it
is 2
> 256x4 RAM chips...if anyone has these or can let
me know where i can
find
them could you
please let me know
I've seen places with the 1822s for sale in the past couple of years. not the same, but B.G. Micro has 2102s for <$1 each
(the web page from
their
online catalog is at
http://www.bgmicro.com/pdf/page5.pdf)
Look for 2101 or 5101 (moto called them 145101) they are all the same.
You could always use a more modern 2016 or 6264 or such
and just tie the
upper address lines to 0. You can scavenge those from old Ethernet
cards
and the like. The speed requirements of the 1802 are
not harsh. I
think
you can get away with 450ns RAM on a 1Mhz design.
At 2mhz clock it wants 500ns or so rams, at 1mhz you can use 1uS
(1000ns!)
parts easily.
If the writer cant find any let me know... I have some.
Allison