RE: Unidentified chip -- Spoiler for HP 1260-0339
It doesn't even shunt across; it's just 16 pins in a DIL package floating? Strange. If it were a manufacturing test, one wouldn't expect it would show up in production machines? Yes. It is just 16 pins unconnected to each other. As I mentioned some messages ago it is used as a connector. It's soldered to the board so you can fit one of those 'IC Test Clips' on top and pick up 16 signals. I came across it on the test board for the HPIB interface for the HP9830 (where it has the HPIB signals wired to the pins). Another place you find it is on the test board for the HP Logic Comparator (you know, the tool that compares a reference IC signals with those on a chip on a PCB). The Logic Comparator has a test clip to fit onto the IC on the board under test in normal use, to test said Logic Compator there is a test board with a bit of logic wired to one of these empty 16 pin packages that you put the Logic Comparator test clip on. -tony
Re: Unidentified chip -- Spoiler for HP 1260-0339
Pin-out? Data sheet?
RE: Unidentified chip -- Spoiler for HP 1260-0339
And come to think of it, I bet those dummy chips were used for training people to hand stuff boards as well. The Amstrad PCW8256 (word processor) came with 256K of RAM but could be expanded to 512K essentially by adding another 8 41256 DRAM chips. Some companies in the UK sold the 9-chip kits used to expand PCs (with parity memory) for this, telling you to use the extra chip to practice with. However the HP package I mentioned is the only time I've seen one of these dummy chips used on a production board. -tony
Re: Unidentified chip -- Spoiler for HP 1260-0339
On 08/06/2015 02:25 PM, William Donzelli wrote: It could also be a chip used to test an auto-insertion machine or wave solder machine. If memory serves, they'll use correctly pinned but fake parts to test those processes before moving to the more expensive real thing. Yes, there were a few companies that made dummy chips for exactly that reason. These days, the robots are much better, so I doubt the practice of using dummy chips still exists. They definitely still exist. I doubt many people use them for PP testing, except maybe the people who MAKE the PP machines. But, larger outfits do extensive thermal profiles, cross-section microscopic examinations of solder joints and all sorts of exhaustive tests on soldering and other parts of the process. They use the dummy chips for testing the quality of these processes. They may run 25 boards with different thermal profiles to find out what gives the best soldering results. Jon
RE: Unidentified chip -- Spoiler for HP 1260-0339
Amazingly there is nothing inside that 16pin DIL package. No silicon chip, no thick-film resistor network, nothing. It is just a package with the pins. Are you sure? They might have gotten a really good deal on Well, I've not x-rayed one, but I could detect no conductivity or diode junctons between the pins. house-marked Signetics 25120 chips, with not all of the address lines bonded out. I've wondered why there wasn't a self-addressing serial version of the 25120, for First In Never Out stores. That would fit in a 16 pin package I think. -tony
Re: Unidentified chip -- Spoiler for HP 1260-0339
It could also be a chip used to test an auto-insertion machine or wave solder machine. If memory serves, they'll use correctly pinned but fake parts to test those processes before moving to the more expensive real thing. Yes, there were a few companies that made dummy chips for exactly that reason. These days, the robots are much better, so I doubt the practice of using dummy chips still exists. -- Will
Re: Unidentified chip -- Spoiler for HP 1260-0339
On Thu, 6 Aug 2015, Eric Smith wrote: On Thu, Aug 6, 2015 at 10:22 AM, tony duell a...@p850ug1.demon.co.uk wrote: Amazingly there is nothing inside that 16pin DIL package. No silicon chip, no thick-film resistor network, nothing. It is just a package with the pins. Are you sure? They might have gotten a really good deal on house-marked Signetics 25120 chips, with not all of the address lines bonded out. It could also be a chip used to test an auto-insertion machine or wave solder machine. If memory serves, they'll use correctly pinned but fake parts to test those processes before moving to the more expensive real thing. g. -- Proud owner of F-15C 80-0007 http://www.f15sim.com - The only one of its kind. http://www.diy-cockpits.org/coll - Go Collimated or Go Home. Some people collect things for a hobby. Geeks collect hobbies. ScarletDME - The red hot Data Management Environment A Multi-Value database for the masses, not the classes. http://scarlet.deltasoft.com - Get it _today_!
RE: Unidentified chip -- Spoiler for HP 1260-0339
As a total aside, on some HP boards there is a 16 pin DIL package with the part number 1260-0339. Any ideas what that chip is? What chip? Amazingly there is nothing inside that 16pin DIL package. No silicon chip, no thick-film resistor network, nothing. It is just a package with the pins. The purpose of it? It's a connector (!) to fit one of those IC test clips on to monitor various signals. -tony
RE: Unidentified chip
This all assumes it is a TTL and not an ECL or even and analog chip, such as an opamp. Or a resistor network, diode network, transistor array, programmed PROM, microcontroller, etc, etc, etc. As a total aside, on some HP boards there is a 16 pin DIL package with the part number 1260-0339. Any ideas what that chip is? -tony
RE: Unidentified chip
Tony wrote... - As a total aside, on some HP boards there is a 16 pin DIL package with the part number 1260-0339. Any ideas what that chip is? - Is it on any boards related to the HP1000 or 21MX computers? If so... what board? J
Re: Unidentified chip
On 08/04/2015 1:48 PM, dwight wrote: This all assumes it is a TTL and not an ECL or even and analog chip, such as an opamp. Dwight It might be possible to identify it a bit. Using the Diode Test of your basic multi-meter you can probably figure out if there is a ground and Vcc pins by comparing the likely candidates (pin 8 for gnd, and 16 for Vcc) against other TTL based ICs. If they don't match then chack against pins 5 and 12 which are alternate G Vcc pins on some TTL. If no joy matching to TTL, then make a log of the various pin voltages relative to other pins and see if there is a pattern that emerges. Compare to CMOS next, then drag out a 16 pin OP-Amp based IC and see if it shows anything similar. I find that inputs and outputs on TTL do show a difference in voltage drops relative to Vcc and G, and also which way you use the probes. I did a small write-up years ago as a starting point: http://www.flippers.com/service.html#diode John :-#)# -- John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9 Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, VideoGames) www.flippers.com Old pinballers never die, they just flip out
RE: Unidentified chip
From: j...@mercury.lcs.mit.edu snip It's a 16-pin DIP, with the following on it (in three separate lines): 1028126, D39315-A, and CS9336P. The first number looks like the numbers I've seen on a couple of other un-identified chips, made by TRW. (I hope they aren't something classified I'm not even supposed to have! :-) Anyone have any idea what these things are? Thanks! Noel Have you tried an ohm meter on them? They might be R-Packs. Dwight
Re: Unidentified chip
On 08/04/2015 11:40 AM, John Robertson wrote: You could always get one of those inexpensive TTL device identifiers to see if the house number crosses over: http://www.ebay.com/itm/281682288251 My Xeltek programmer has that function--and it works for some common TTL ICs, but gets a lot less reliable with the complex function ones. I suspect that the eBay model is not much better. --Chuck
RE: Unidentified chip
This all assumes it is a TTL and not an ECL or even and analog chip, such as an opamp. Dwight
