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Substitute for a Panasonic KX-P43 32K RAM chip? (KX-P2123 Printer)

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legendre

Experienced Member
Joined
Jan 24, 2014
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Anybody know what the deal is with the 32K buffer expansion chip sold by Panasoinc, for their later dot-matrix printers? The Panasonic part number is KX-P43 "32K buffer", and it can be used to expand the buffer (read: downloadable font menory) for printers in the KX-P2123 family.

I can't find one anywhere, but I do have quite a few 32K x 8bit static RAM chips around here. I doubt Pana had a custom chip made, so there has to be a generic part that just drops-in, eh?

Any info would be great. Or hey, if you have one of these printers with the KX-P43 installed, maybe you could just pop that sucker open and post the markings on the chip.. :cool:

Thanks!!
 
Chuck(G) said:
According to this, it's just a standard 32Kx8 SRAM chip (28 pin DIP).
Click to expand...

Hey Chuck,

That is the ONLY lead I've had so far, so mega-thanks to you for that! I'll dig right in and see what I can see...

Thanks!!

ETA: The supplied info (off-site) doesn't address my printer. I can't get into it by "popping off" the front panel.. it's gonna take a lot of study, or a service manual

ETA 2: Okey! Found my way in. Two screws visible, looking downward into the front of the case, after the clear/smoke top cover is removed. Pull those two screws, and the entire top just hinges off to the rear.

Too bad, tho!! The RAM this thing wants is of a different package. It expects a wide 28-pin DIP, and all of my chips are narrow 28-pin DIP, like you might see used as on-board cache on older 486 / Pentium MoBos.

Anybody want to trade some SRAMs for some SRAMS?? ;-) Gaahh!
 
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One more quick question..

That post you linked specified 120nS "or faster" SRAM.. so can I go as fast as even 35nS if that's what's available?

Also, they didn't mention if this is 3.3V or 5V. I +think+ it's CMOS, so that would be 3.3V.. if it's CMOS.

ETA: I suppose I could just measure the socket voltage now, couldn't I? Guess I need a datasheet.
 
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Thanks Chuck. I'd found a couple of datasheets as well, and seems like they all have the same power supply pinout:

Vcc = 28
Vss = 14

I measured the socket, and 5V it is. Well, it's 4.95 - but what's a few mV between nerds? ;-)

Ordering up one of these: eBay item #321165655512 - IDT71256L35P 35NS 600 MILL 28-PDIP CMOS STATIC RAM 256K (32K x 8-BIT) "PULL" - $3.99 shipped.

The price is right, and what the heck.. all the rest of the parts in the printer are used.. eh?
 
I certainly will do just that. If the seller is on the ball, I should have the part on Friday - and a report later that same day. Panasonic sure made it easy enough to do this, just those two screws (and the platen knob). Once you're in, there's a big old arrow with the legend "OPTION CHIP" pointing at the empty socket between the RAM and ROM chips.

It should be fun to see what kind of fancy fonts I can get it to load & use.

Thanks again for the assist.
 
Chuck(G) said:
Panasonic laser printers, on the other hand, each seemed to have a different memory expansion card--and CPU inside the print engine.
Click to expand...

I have even less experience with their laser printers. I'm old and set in my ways, so I've tended to stick with HP LaserJets.. had a IIIp for ten years, then a 6mp for another four. Ran them off an HP JD500X server.

Then recently, I fell into a Brother HL2270DW - and I hate to say it, but it's really a nice device.. I'm impressed with it, paricularly the price to features ratio, and the cheap toner refills. The duplexing - which is very reliable - is a nice touch as well.. I can recommend it.

IMHO the Panasonic 24-pin printers are the best of the crop from the early-mid 90s. Small, light, quiet and reliable as the average stone. The Epson stuff maybe tended to be a bit more rugged, but I can't say that there is any significant reason to pick one over the Pana.

ETA: When this is all said & done, I'll write up a tutorial on it. No reason everyone who owns a printer of this family shouldn't max out the capabilites, when the parts are this darn cheap.. $2-5!
 
Panasonic basically took their heavy-duty office copier (KX-P4450) and turned it into a printer. They did not use the HP-style cartridges; you filled the toner reservoir with powered toner manually. At one time, I had three of the beasts; now I only have a 4455 Postscript printer sitting unused in a corner. Circa 1988 or so. Real workhorse and quite expensive. I replaced it some time ago with a Xerox NP2825--takes ledger (11x17" paper), has a duplexer, hard drive, ethernet connection--a nice machine.
 
legendre said:
IMHO the Panasonic 24-pin printers are the best of the crop from the early-mid 90s. Small, light, quiet and reliable as the average stone. The Epson stuff maybe tended to be a bit more rugged, but I can't say that there is any significant reason to pick one over the Pana.

ETA: When this is all said & done, I'll write up a tutorial on it. No reason everyone who owns a printer of this family shouldn't max out the capabilites, when the parts are this darn cheap.. $2-5!
Click to expand...
I fully agree. I still use them as primary printers and have several for sale as well:

http://www.vintage-computer.com/vcforum/showthread.php?33924-Several-24-pin-Dot-Matrix-Printers

The KX-P1124 I'm using right now has the 32K buffer chip in it that I put in it twenty-some years ago. :)
 
Hey Stone,

Stone said:
I fully agree. I still use them as primary printers (...) The KX-P1124 I'm using right now has the 32K buffer chip in it that I put in it twenty-some years ago. :)
Click to expand...

Cool beans! Did you ever run it out to the limits, see how many different fonts you could print on one job?

As for selling dot matrix printers, there are basically three target users for them these days:

1) Corporate IT security (you can't delete or fudge a system log, that's been sent line-by-line to the LPR)
2) Industrial / Scientific applications, as replacements for legacy systems that only work with line printers (think data logging, etc)
3) Vintage compy dorks like you, me and pretty much everyone else in earshot.. =)

So while it's a bit limited, there are still a few viable niches. Or that's how I view it all.

-Legs
 
legendre said:
Hey Stone,

Cool beans! Did you ever run it out to the limits, see how many different fonts you could print on one job?
Click to expand...
No, I didn't. I got it so that the 286 I was using it on in the early 1990s would get freed up quicker (nearly immediately) during printing and not remain tied up for extended periods while the computer was still sending the job to the printer. Kinda like a hardware print spooler.
 
That worked just fine, gents. Here's a pic of the settings table printout, indicating that the buffer is in-place and enabled:

Panasonic_KX-P1232_Buffer_enabled.jpg

Couldn't have been easier to install.. since the chip was a 'pull', I didn't have to fiddle around forming the leads to match the socket - it just lined up and snapped tighly into place. To review, I used an IDT 71256L35P (32K x 8 / 35ns / 5V / CMOS SRAM) which cost $3.99 including shipping. But any 32K x 8 / 5V SRAM should work, if it's 120nS or faster (not hard to find) and it fits the socket.

A cheap upgrade to be sure.
 
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Apologies for digging up this old thread, but I have Panasonic KX-P1180 that takes the same KX-P43 expansion RAM. The item OP legendre found is no longer available, but I found this instead: https://www.ebay.com/itm/5pcs-HM6264LP-70-HM6264LP-HMC-DIP24-General-Purpose-Static-RAM-NEW/123356475823?_trkparms=aid%3D555018%26algo%3DPL.SIM%26ao%3D1%26asc%3D20131003132420%26meid%3Da6c5de69792b4036bca5308bc1bc0550%26pid%3D100005%26rk%3D3%26rkt%3D12%26mehot%3Dco%26sd%3D163633795088%26itm%3D123356475823%26pmt%3D1%26noa%3D0%26pg%3D2047675&_trksid=p2047675.c100005.m1851

The item shown is wide-body, 28 pin DIP SRAM although the poster lists it as 24 pin. The speed is 100 ns. Is this suitable as a substitute?

-CH-
 
Stone said:
I've been using Toshiba TC55257BPL-10 chips in my Panasonic printers for years without issue.
Click to expand...

Got the Toshiba chip: Now I have to figure out how to open the case. There are three "tabs" at the rear which appear to sit in three small holes and secure the top to the bottom half in the rear. There are two slots in the bottom toward the front, near either corner, that seem to be access holes for a pry-apart release tab; I've seen those before.

I don't know if there are any others that I'm missing, and I don't know if there's anything behind the front panel. If anyone has been through this drill and knows what to do, please advise.

Thanks again for your help.

-CH-

Pics attached:

FRONT.JPG BOTTOM.JPG REAR.JPG
 
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