I believe it is a 5155. It is an XT and a monitor in a box. Peace... Sridhar On Mon, 23 Apr 2001, Mike Ford wrote:

I have around 50 or so printer memory expansion boards, ALL unpopulated. I guess they ship them blank, then the vendor installs the memory as units sell, but I don't have any chips. Where is a good place to find memory chips for printers ie 1 MB x 1 bit? (sockets are 18 pin I think, but it doesn't go into anymore detail) Given the 16 to 24 devices per board I am guessing I would buy maybe in lots of 100 or so.

About half look to be JetRam, and many of them are for HP, II, IIP, III etc., but also TI, Oki, etc.

Well ... those chips are 256x4 devices. I have a Pacific Data Products board in one of my LJ-iii's but it uses 1Mx1's, which are 18-pin devices. Dick ----- Original Message ----- From: "Russ Blakeman" <rhblake(a)bigfoot.com> To: <classiccmp(a)classiccmp.org> Sent: Thursday, May 03, 2001 6:53 AM Subject: RE: 1mb x 1 memory chips for printers

So am I to assume (since I haven't dealt with loose DRAM in years) that the HY51C4256S-C printed on the 20 pin DIP chips are 4x256, and if so anyone have a source? I need at least 16 to pop this Laserjet III up to the full 4 mb. I don't imagine they are the same as the old 256k DRAMs in the older PC,XT and some AT class machines...

I thought they might be the same as the old 4256 (and possibly the 41256) dram that we used to use in them. The chips soldered on don't have the speed on them so I'm sure just testing some 70's and 80's will let me know if they'll work. I'm almost into my old chip stashes in storage so maybe I'll have an LJ III with 5 mb soon. Thanks

Dogpile search on 51c4256* yields 3 maybes, USbid.com coughs up the following and apage more after I register. 44256-SOJ(HM514256AJP-8;T... --- HIT --- 1000 US $ 1.2966 Fixed Price Buy Now 44256-SOJ(HM514256AJP8) --- HIT 89 2380 US $ 2.1611 Fixed Price Buy Now MSM514256A80ZSB --- OKI --- 68 US $ 8.2583 Fixed Price Buy Now Can't say that I am happy even at a buck each, but I have barely started to look. Anybody have a part number for the 1x 1 MB parts, or a guess if the above parts look correct? (yeah I know, look in one of your old data books....). Do I want dip or is that what soj means?

You seems not to realize that all these old memories before FPM is no longer made, this cause that price to explode. Even EDO is cut severely in production or few productors has stopped putting out EDO stuff. Secondly, seems only that 1M x 1bit DIPs is most unpopular type and most rare to find anywhere even still socketed in old boards. Since then, I have only seen this kind 8 years ago on my rare few fingers on one hand. At that time, 64K and 256K chips of any bits is wildly popular and jumped right over 1M x 1bit and 1M x 4bits to 30 and 72 simms. Even I didn't own none of indivdual 1M chips on my hand ever used or new except for one soldered down 8MB intel 32bit card using 1M x 1bit 80ns DIPs for Intel 386 motherboard I found at junkyard for $5 2 yr ago. it's still gathering dust since I haven't seen Intel 386 motherboard for that 8MB card. Very frustrating to watch prices climb to sky-high prices on these stuff. There are too many working 486 and Pentiums even early slot 1 in use using 30pin or 72pin. As well as still-useful Mac machines still use both FPM and EDO in both 30pin, 72pin simms and DIMMs (that's right there's FPM and EDO DIMMs, saw EDO DIMM in late IBM pentium box few days ago.) as well as other types of memories especially for video. Keep digging for very old clone 286 and 386dx, 386sx motherboards these often used DIP chips either 256K or 1M in each socket. You might score one full of 1M x 1bit chips. Also some early deskpros used socketed DIPs as well. Or, just pay through the nose and lose few appendages even losing sexual ability if you have to grab those duious "golden" memory pieces. Cheers, Wizard

Sounds like what he needs is the IR desolderer I used when I worked last Xmas for Jabil Circuits in Louisville - it looks like an oversized microscope and you aim the light source on the part you want to remove and watch the TV display (magnified view) for when the solder drops out from becoming soft. Pull the part and set the board to the side. Strange thing is that it affects the solder, not the chip. I don't think he wants to spend around $10k for a desoldering tool that would mostly just impress people.

--- Mike Ford <mikeford(a)socal.rr.com> wrote: Hmm... me, too; but I doubt you were talking about me here. I have a Gorf machine I built up out of boards found at a local scrapper (when I was in high school) and parts from two cabinets (proper glass, proper paint job, marquee, etc). _And_, just the other night, I fired up my solder pot to extract some parts from dead x86 motherboards. -ethan ===== Visit "The Seventh Continent" http://penguincentral.com/penguincentral.html __________________________________________________ Do You Yahoo!? Yahoo! Auctions - buy the things you want at great prices http://auctions.yahoo.com/

You're probably right on this, I thought they were 3 or 4 bucks each but they were likely higher. Never heard of $17 each though, would have never upgraded at that money (average bank of 8 x $17 gets to be a huge chunk of cash)

I think I have a bunch of 1Mx1 drams here :) At 02:06 PM 5/4/01 -0700, you wrote: