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View Full Version : 8087 Upgrade Fail; Fake chip?



mcsew2k
April 20th, 2012, 09:06 PM
My first ever 8087. I received it sealed in an anti-static envelope; seller insists it is new old stock. I don the proper anti-static strap and proceed to plug in the chip. I set the DIP to OFF (Block 1, Switch 2) and my system won't even POST. Does anyone know how I can check if this chip is a fake (without tearing it apart)?

Chuck(G)
April 20th, 2012, 09:14 PM
Doesn't sound as if you've got a good chip there. I assume that you did the usual checks; making certain that there are no bent pins and that the DIP is oriented correctly in the socket (i.e. not plugged in backwards or offset by a row).

mcsew2k
April 20th, 2012, 09:29 PM
Yea, no bent pins and in the right way. I just pulled out my XT and the same thing, no POST. I used Buy-it-now on eBAY and didn't notice I was buying from Hong Kong until I was paying. Not worth sending back, but I want to see if I can figure out if it is an intentional fraud, or simply a bad chip.

Chuck(G)
April 20th, 2012, 09:33 PM
The HK sellers are variable. Some are outright frauds, selling relabeled chips (I suspect that your 8087 isn't even one under the ceramic--it is a cerdip, not a plastic chip).

On the other hand, I've had some great experiences with HK sellers.

You have to be careful.

Stone
April 21st, 2012, 03:17 AM
This one's in service, fully functional and available.


8602

mcsew2k
April 26th, 2012, 10:02 PM
This one's in service, fully functional and available.

I got a refund so I'm back in the market. I need a 8087-2 because I also have an 8 MHz turbo XT motherboard I want to be able to use it in once in a while.

mcsew2k
May 24th, 2012, 05:33 PM
I now have a 8087 that lets the system boot. Is there a program I can download that will test and/or exercise the 8087 chip?

Chuck(G)
May 24th, 2012, 07:13 PM
Don't feel too bad about the first chip. A recent report shows that fake chips show up in US military hardware (http://newsletters.eetimes.com/portal/wts/cemciv2dr0AqedA8oa7T4AigrbzbFc).

There are probably better tests, but most of the early spreadsheets such as Lotus 1-2-3 could take advantage of the 8087.

modem7
May 24th, 2012, 08:26 PM
Is there a program I can download that will test and/or exercise the 8087 chip?
CheckIt Diagnostics will check/test the 8087 maths co-processor.
The particular check/test is done during the 'System Board' test within CheckIt.
CheckIt refers to the maths co-processor as the "NPU" (numeric processor unit).

StowComputers
May 25th, 2012, 11:52 AM
I remember fitting an 8087, and needed it for rendering. You could try a raytracing test with POV Persistance Of Vision, although I don't know if this software is still around. It knocked the rendering time of a picture of fractal generated islands in the sea from 12 hours without the co-processor to about 20mins with it. I remember being bowled over by that!

deathshadow
May 25th, 2012, 10:38 PM
although I don't know if this software is still around. It knocked the rendering time of a picture of fractal generated islands in the sea from 12 hours without the co-processor to about 20mins with it. I remember being bowled over by that!
POV-RAY is still around, though it's been a while since they provided 16 bit binaries.

http://www.povray.org/

3.1g was the last version to have official DOS builds.
ftp://ftp.povray.org/pub/povray/Old-Versions/Official-3.1g/MS-Dos/

3.5/later they dropped 16 bit OS support -- but it's matured into a real 3d suite when paired with modeling software like Moray, which is now free as the folks at Pov-Ray put together the means to acquire control of it.

Still fun to play with -- especially with 3.5/later supporting multiprocessing so that 20 minutes is down to a few seconds on a i7... though you can still crank the quality and scene complexity up to where some scenes take hours or even days on a modern system -- stuff that would have taken years at 8087 speeds.

ibmapc
May 26th, 2012, 10:50 PM
I now have a 8087 that lets the system boot. Is there a program I can download that will test and/or exercise the 8087 chip?
9074 I believe this is the Intel test utillity for the 80x87 math coprocessor family.

mcsew2k
May 30th, 2012, 08:13 PM
CheckIt Diagnostics will check/test the 8087 maths co-processor.
The particular check/test is done during the 'System Board' test within CheckIt.
CheckIt refers to the maths co-processor as the "NPU" (numeric processor unit).

I had an issue getting CheckIt onto a floppy that would work in the PC. To make a long story short, I was able to put in on a native 720 KB floppy using a DTK controller and it ran and passed my 8087 chip. Thank you for the help.

I only have Lotus 123 on catridges for the PCjr, but I know I have Borland QuattroPro. I will do some benchmark testing in the near future.

Stone
May 31st, 2012, 03:22 AM
I had an issue getting CheckIt onto a floppy that would work in the PC.FWIW, CheckIt goes on two 360K floppies. IIRC, the .ovl goes on the second and the rest on the first.

pbirkel@gmail.com
March 7th, 2015, 10:20 PM
9074 I believe this is the Intel test utillity for the 80x87 math coprocessor family.

Attachment now gone AWOL, at least for me. Can anyone point me to the original? Or PM me if you prefer.

Many thanks!

Stone
March 8th, 2015, 04:16 AM
http://www.filewatcher.com/m/mcpdiag.zip.11418-0.html

andykmv
April 1st, 2015, 04:37 AM
they also made a huge difference with cad drawing manipulation/renderings!

oblivion
April 15th, 2015, 07:14 AM
Surprisingly all the cheapo 8087's I've gotten from Chinese sellers seem to work fine and pass testing.

Stone
April 15th, 2015, 07:34 AM
It doesn't matter who's selling the chips -- they're all made in Asia anyway.