Were to buy 2114L ram?? - Page 1
Forum section: electronics / general

author: The Soulman
author_rank: Super Contributor
timestamp: May 08, 2020, 10:38:25 am
content: I have a old Keithley 192 digital multimeter with faulty 2114 rams, main cpu is 6808 with 6522.Thirty years ago I would have gone to the computer/electronics store around the corner..Were to buy 2114l ram in 2020? (outside dodgy ali-e and ebay offerings?)

author: jfiresto
author_rank: Frequent Contributor
timestamp: May 08, 2020, 10:55:57 am
content: The Silicon-Ark has new old stock2114s for 4 poundseach.

author: The Soulman
author_rank: Super Contributor
timestamp: May 08, 2020, 03:59:09 pm
content: Thanks, will probably order next week if nothing else comes up.

author: granzeier
author_rank: Regular Contributor
timestamp: May 08, 2020, 09:01:08 pm
content: https://www.jameco.com/webapp/wcs/stores/servlet/ProductDisplay?langId=-1&storeId=10001&catalogId=10001&productId=38973&CID=EPIPRODUCTLINK- $2.95 ea (2.72 Euro) - I don't know about shipping to you.This is for the 2114N, which is supposed to be a low-power version. The 2114A should be drawing 370 mW, but I cannot find a good power rating for the N. Either way, since the full-strength 2114A is supposed to draw ~500mW, the worst that should happen is that yourbattery will drain a tiny bit faster.EDITED - I just looked it up, and it runs on mains power. So the only trouble might be that it will run atinybit hotter (but probably not enough to notice.)

author: The Soulman
author_rank: Super Contributor
timestamp: May 08, 2020, 09:18:45 pm
content: Thanks for tip but shipping makes it costly, $18 and above..Will see if they have anything else I may need.Although I do want to minimize the power consumption and heat, a couple hundred mili Watts wouldn't be a deal breaker.

author: granzeier
author_rank: Regular Contributor
timestamp: May 09, 2020, 01:51:39 am
content: OUCH! That is pretty high.I believe that it only costs me about $5-$6 to send a small packet pretty much anywhere in the world (via U.S. Postal Service.)PM me your address, and on Monday I will get a quote on shipping a package to you. Also, send how many your meter need, and I will see what I have.

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: May 10, 2020, 07:48:25 pm
content: Well if you have the space you can whack in almost any kind of SRAM chip, just tie the unused pins. Cache SRAM chips from 486-era motherboards come in 28 pin DIP packages and have like 128kx8bits.Then again I got all mine when people were throwing these out by the truckful and I didn't pay much for them...

author: granzeier
author_rank: Regular Contributor
timestamp: May 11, 2020, 01:34:35 am
content: Quote from: Alex Eisenhut on May 10, 2020, 07:48:25 pmTheoretically that would work; the trouble is that it would be wildly impractical. The 2114 is only 4 bits wide, and so you would have to create a daughter board with pins which perfectly line up withbothof the 2114 chips, and then run the address, power and control lines to both chips, while running half of the data lines to each chip separately. That also assumes that there is, as you mentioned, enough room inside the meter's case for the additional board, and the new RAM chip.

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: May 11, 2020, 05:25:36 am
content: Quote from: granzeier on May 11, 2020, 01:34:35 amYou mean "perfectly practical", you just described the task, it's hardly nuclear fusion. And given the pricing of PCBs, it would end up cheaper than a NOS 2114.

author: Syntax Error
author_rank: Frequent Contributor
timestamp: May 11, 2020, 08:35:32 am
content: FYI the original ZX81 was populated with a pair of 2114's as 1K x 4bit. Sometimes a single 4118 as 1K x 8bit depending on availability. I understand the Vic20 also used lots of 2114L's Thus it may be cheaper to rip some junk retro kit from ebay than go for pre-ripped antiques.Vic20 Ram schematichttps://www.commodore.ca/manuals/funet/cbm/schematics/computers/vic20/251027l3.gif

author: granzeier
author_rank: Regular Contributor
timestamp: May 11, 2020, 10:59:29 am
content: Quote from: Alex Eisenhut on May 11, 2020, 05:25:36 amOk, I guess that you must have more experience at PCB design than I do. It's just that in my experience (with over 100 boards): it is not too difficult to design a PCB to do this, but to get the measurements of the two 2114s perfect is the killer. And, being cheaper than the 2114s would demand that you get the measurements perfect on the first try.Go ahead and offer to design the board for Soulman; I'm sure that he will appreciate it.

author: The Soulman
author_rank: Super Contributor
timestamp: May 12, 2020, 05:20:14 pm
content: Quote from: Alex Eisenhut on May 11, 2020, 05:25:36 amYeah, but why design it when you can buy it for 4 dollars on ebay?

author: The Soulman
author_rank: Super Contributor
timestamp: May 12, 2020, 05:21:55 pm
content: Quote from: granzeier on May 09, 2020, 01:51:39 amThat is very kind of you, needs two, will send pm.

author: edavid
author_rank: Super Contributor
timestamp: May 12, 2020, 06:01:15 pm
content: Quote from: granzeier on May 09, 2020, 01:51:39 amYou are mistaken. Minimum retail cost for a USPS package sent to the Netherlands is $14.50.If you sign up for a pirateship.com account you can use their "Simple Export Rate" of $10.95, but I haven't found any cheaper option.OP should just order those dodgy parts from eBay or AliExpress - I have not had much trouble with them.

author: edavid
author_rank: Super Contributor
timestamp: May 12, 2020, 06:05:48 pm
content: Quote from: granzeier on May 11, 2020, 01:34:35 amInstead of worrying about spacing, just use an 8 bit RAM to replace each 2114

author: jfiresto
author_rank: Frequent Contributor
timestamp: May 12, 2020, 06:35:06 pm
content: Quote from: edavid on May 12, 2020, 06:01:15 pmWould that be by uninsured First Class International? Insurance would add another $16 minimum.

author: edavid
author_rank: Super Contributor
timestamp: May 12, 2020, 07:02:19 pm
content: Quote from: jfiresto on May 12, 2020, 06:35:06 pmYou can get third party insurance for $1.35.

author: The Soulman
author_rank: Super Contributor
timestamp: May 12, 2020, 07:25:22 pm
content: Quote from: edavid on May 12, 2020, 06:05:48 pmI haven't decided either way,First, I'd probably replace the faulty rams with used but known working direct replacements to make sure that was the fault and see if the 100 point data-logging is then working reliable.Secondly, how long will 30 year old, used ram chips last?Doing a mod to more modern chips might be worth the hassle in the end, so any suggestions for those is much appreciated.Or is it a good time to learn arduino and use that?I'm not to worried about hacking some hardware together, but haven't done any digital designs and programming apartfrom turbo pascal and some basic shift registers etc. over twenty years ago..time flies when you're getting old(-er).So any tips and pointers there are also much appreciated.

author: jfiresto
author_rank: Frequent Contributor
timestamp: May 12, 2020, 07:26:22 pm
content: Quote from: edavid on May 12, 2020, 07:02:19 pmOh, dear. That actually makes sense in a twisted sort of way.

author: The Soulman
author_rank: Super Contributor
timestamp: May 12, 2020, 07:28:26 pm
content: Quote from: edavid on May 12, 2020, 07:02:19 pmInsurance isn't mandatory, is it?

author: edavid
author_rank: Super Contributor
timestamp: May 12, 2020, 08:09:47 pm
content: Quote from: The Soulman on May 12, 2020, 07:25:22 pmProbably for the life of the meter.I suppose if you are worried you could try 5114s... they might last longer on the basis of lower power -> less heat.BTW, how did you decide that the existing 2114s are bad?

author: edavid
author_rank: Super Contributor
timestamp: May 12, 2020, 11:11:50 pm
content: Did you see this eBay listing?eBay auction: #323778016598

author: The Soulman
author_rank: Super Contributor
timestamp: May 12, 2020, 11:16:56 pm
content: Quote from: edavid on May 12, 2020, 08:09:47 pmGood question, just a hunch really, apart from the 100 point data logging and the self-test mode everything else digital on the meter works just fine.The data logging works as intended except for reading back data points, sometimes there is no data, sometimes a little data, sometimes garbage data.Also from what I understand is the self test uses the ram.Yes it could also be that the uc garbles up the writes, but all other logic ic's driven from it are functioning fine,why would only the memory lines fail?My idea was to get some chips put them in and go from there.

author: The Soulman
author_rank: Super Contributor
timestamp: May 12, 2020, 11:22:12 pm
content: Quote from: edavid on May 12, 2020, 11:11:50 pmNope, thanks.

author: granzeier
author_rank: Regular Contributor
timestamp: May 15, 2020, 04:43:14 pm
content: Soulman,Did you ever order those chips from E-Bay?

author: The Soulman
author_rank: Super Contributor
timestamp: May 15, 2020, 05:27:57 pm
content: Quote from: granzeier on May 15, 2020, 04:43:14 pmNo, seller only accepts paypal that I don't have.

author: granzeier
author_rank: Regular Contributor
timestamp: May 16, 2020, 01:48:34 am
content: Ok, well I do have PayPal, and have ordered several of the 2114N chips (mine were in considerably worse than terrible shape - I threw them out.) Expected delivery is between 2 Jun and ~30 Jun. How many do you need?

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: May 16, 2020, 08:01:54 pm
content: Quote from: The Soulman on May 12, 2020, 05:20:14 pmInteresting interpretation of the word "if".I didn't say "when", you did that.Ifsomething akin to this existed for your situation, and it was cheap enoughhttp://www.dasarodesigns.com/product/mps-6550-commodore-pet-2001-ram-adapter/wouldn't you buy it instead of arguing with defeatists?In any case, it's far better to wait for replacement ICs if you don't happen to have a SRAM to play with.

author: The Soulman
author_rank: Super Contributor
timestamp: May 17, 2020, 10:05:11 am
content: Quote from: granzeier on May 16, 2020, 01:48:34 amJust need two,I've also found a seller on ali express that sells five for just a few euro's including shipping, altoughit will take at least a month before its here I will try that first, as I'm afraid shipping cost from the USAare prohibitively high.

author: The Soulman
author_rank: Super Contributor
timestamp: May 17, 2020, 10:10:50 am
content: Quote from: Alex Eisenhut on May 16, 2020, 08:01:54 pmDidn't want to be rude, yeah a (diy) adapter board is still a option when 2114 supplies dries up but that doesn't seemto be the case at the moment.

author: markce
author_rank: Regular Contributor
timestamp: May 25, 2020, 11:03:54 pm
content: @soulmanI still have a few 2114L 's in my parts bin. New, unused.PM me if you're interested.

author: sarahMCML
author_rank: Regular Contributor
timestamp: May 31, 2020, 06:13:25 pm
content: Hi,I've just come across 4 OKI MSM2114LRS which you are more than welcome to have, gratis. Just priv-mail me your address and I'll drop them in the post to you tomorrow.I don't know their age or status, but they look unused. I was trying to find a tube that I purchased back in the late 1970's/ early 80's, and which I should still have, but I cannot find them after about 5 moves, sadly. Else I would have offered some that I know are unused!Just let me know if you still want them.Regards,Sarah.

author: granzeier
author_rank: Regular Contributor
timestamp: June 09, 2020, 09:20:06 pm
content: Soulman,Four chips are on their way.See PM for US Postal Service tracking number.They did not give me any estimated time of arrival.