25 Dec
2009
25 Dec
'09
11:12 a.m.
Hi,
This is my annual 1Mx4 DRAM memory chip post.
I'm looking for some old DRAM memory chips with the following specs:
20-pin DIP memory chips
(16) 1meg x 4-bit dips make up a bank of 8mb.
Should be 60-ns
Fast Page Mode
non-parity
An example would be Toshiba TC514400AP-60.
Other manufacturers might use the following base part numbers:
Fujitsu MB : 814400
Goldstar GM : 71C4400
Hitachi HM : 514400
Hyundai HY : 514400
Micron MT : 4C4001
Mitsubishi M5M: 44400
I have some in surface mount (in a goofy 26/20 format), but without
small PCBs to convert, they aren't much use. There are some out there
in SOJ, also not useful. Yes, I know some old video cards might have
them, and yes, I know the Epson ActionLaser 1500's have them. I haven't
found a single source in a couple years.
There are some companies, like usbid.com, that have them. All of these
companies have $250-$500 minimum purchases, and I really don't need that
many of them. Or want to pay that much.
The form factor is important, but if I can only get EDO and 80ns, I'll
take those too. :)
Thanks and Merry Christmas.
Keith
25 Dec
25 Dec
12:16 p.m.
On 25 Dec 2009 at 14:12, Keith Monahan wrote:
...1Mx4 DIPs...
There are adapters out there that allow you to mount an SOJ chip on a
DIP plugboard. Judging from the number of requests and lack of
responses on the various Amiga forums, I think that using an adapter
may be the best route.
Cheers,
Chuck
2:02 p.m.
Chuck Guzis wrote:
On 25 Dec 2009 at 14:12, Keith Monahan wrote:
...1Mx4 DIPs...
There are adapters out there that allow you to mount an SOJ chip on a
DIP plugboard. Judging from the number of requests and lack of
responses on the various Amiga forums, I think that using an adapter
may be the best route.
Cheers,
Chuck
Chuck,
Yeah, I've seen those adapters. They are $5.00 each + shipping, plus
require a bunch of soldering. Not to mention, the SOJ chips aren't
really cheap. It could be $100-$200 job plus time for 8mb.
I've searched just about everywhere, including the amiga forums, and I
just can't believe how un-popular these chips must have been. The 256k
x 4's in comparison are available everywhere.
I have some surface mount chips, maybe PSOPs, already that some kind
soul mailed me for free a year or so ago. I just found someone else
with the knowledge to make these carrier boards (not hard if you know
Eagle or the like) and we could likely get them cheaper if we buy a big
pcb full of them.
I already considered making my own board, and if something falls
through, that's likely what I'll do. I would have to measure the
surface mount chip because finding a datasheet for the chip has been
particularly tough (and normally, I can find those types of things) I'm
sure it conforms to some standard so it would only be a matter of time
before I figured out which it was.....
Obviously, and the reason for my post, is that if I could get the chips
by themselves, it would likely save me time, trouble, and money.
Thanks
Keith
3:05 p.m.
On 25 Dec 2009 at 17:02, Keith wrote:
I've searched just about everywhere, including the
amiga forums, and I
just can't believe how un-popular these chips must have been. The
256k x 4's in comparison are available everywhere.
I suspect it was a matter of timing--they arrived at about the same
time that PCs were switching to SIMMs. I've got a couple of old 386
motherboards with both 1Mx1 DIP sockets and SIMM sockets. Later on,
it was SIMMs or SIPPs only.
--Chuck
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