8 Jun
2013
8 Jun
'13
8:26 a.m.
On Sat, 8 Jun 2013, David Riley wrote:
On Jun 8, 2013, at 7:19, Tothwolf <tothwolf at
concentric.net> wrote:
I'll keep that in mind for later. I still don't see spending $80 for 128MB
of ram for a 486 board though, let alone two of them, even if they are
EISA. IIRC, both boards had developed CPU clock problems too, so I should
probably troubleshoot that first anyway.
OTOH, I did pick up 4x 128MB 72-pin SIMMs awhile back for ~$15/ea for a
Socket 7 board that I'm still using, which is working extremely well now.
Those replaced the 2x 32MB and 4x 16MB modules that it had been using for
close to a decade. Most Socket 7 boards can't handle 512MB of ram (128MB
or 64MB max), but it is an exception to the rule and uses an Intel 430HX
(Triton II) chipset along with enough cache for all 512MB.
I still think Intel got pretty stupid in refusing to support 512MB (and
ECC) with their later Socket 7 chipsets, and especially those with SDRAM
(DIMM) support, since that shortsightedness gave the low-cost third party
chipset companies such as VIA the chance to take over that portion of the
market. Had Intel not done that, there might be far more Socket 7 boards
still in use now too. Still, even without ECC support, chipsets such as
the VIA Apollo VP2 are pretty nice.
Your board with 4 30-pin SIMM sockets likely tops
out at 16MB. AFAIK,
no one ever made 8MB 30-pin SIMMs, although at one time there were some
16MB SIMMs available at great expense (~$400.00/ea or ~$25/megabyte).
They're not as expensive now; I just recently put four of them into my
Quadra 700 (which definitely supports them) for about $40.
99% of the boards out there did not support
30-pin SIMMs larger than
4MB though.
That's the rub. Inasmuch as the 30-pin sense lines were ever "standard",
I don't think there was ever a standard sense configuration for 16MB,
which means that the chipset would have to support the rows/cols
configuration (many didn't) and the BIOS would need to manually probe
the bounds of the memory array. Many Macs supported 16MB 30- pin SIMMs,
but my recollection is that more than a few didn't.
I do have a few EISA boards that could (8
sockets, 128MB max), but I
never was able to put my hands on any 16MB 60ns 30-pin SIMMs in matched
sets of 4.
I don't recall if they're 60ns or not, but they're pretty cheap on eBay
now. You can often find them (matched sets, that is) marketed
specifically for Quadra 700s. :-)