17 Aug
2006
17 Aug
'06
6:15 a.m.
Rumor has it that Tony Duell may have mentioned these words:
Hmm.. Both the SAM (CoCo 1 and 2) and GIME (CoCo 3)
chips are pretty much
designed to use DRAM. They output the multiplexed addresses and all the
right timing signals.
Yup.
Surely 41256 DRAMs are not that rare yet?
Nope.
It would be a lot easier to stick 16 of those into a
CoCo 3 to get it
up to 512K.
But the *boards* to stick 'em in aren't exactly easy to find, and Cloud 9
(http://www.cloud9tech.com/) aren't building/shipping any more hardware
(including their 512K upgrade boards) until they get the SuperBoard done;
which might be quite a while yet.
Besides - I have bigger fish to fry. This is part of my evil, twisted plot
for world domination!!!
OK, just kidding, but - to venture into where my brain & dynamic memory
part understanding, the 41256 uses a particular refresh[1]
which newer memory doesn't deal with well[2], so going *beyond* 512K is
problematic.[3] *If* I can figure out how to get 512K of SRAM to work in a
CoCo3, going *beyond* 512K might become a bit easier.
Not to mention - going from SRAM to FRAM would be a pretty easy jump. A
CoCo3 with a "Suspend" switch could be *neat*. ;-)
Or, I might be full of condensed milk, as my father-in-law used to say.
Just my random thoughts for the day...
Laterz,
Roger "Merch" Merchberger
[1] 256 cycle / 8-bit counter / something like that. Did I mention that my
brain doesn't grok DRAM well??? ;-)
[2] 512/1024 cycle / 9-10 bit counter / something like that. Just in case
you didn't catch it, I have DRAMophobia. ;-)
[3] Now we're getting into the world of PAL/GAL/PEEL/CPLD - which is *way*
beyond anything comprehensible to my grey matter.
--
Roger "Merch" Merchberger | "Bugs of a feather flock together."
sysadmin, Iceberg Computers | Russell Nelson
zmerch at 30below.com |