Alright, here we go,

Important note: pin 4 is not common and pin 2 is not +5V (I wish I could 
edit my first post to avoid misinformation).

The numbers were definitely Burroughs house numbers. Fortunately there is 
this document 
(http://bitsavers.org/pdf/burroughs/icData/burroughs_IC_crossref.pdf) that 
at least lists the functions of the chips (page 61). I'm part of the way 
through a schematic of the BIP-8820-1 which certainly agrees with the 
functions of the chips. The 906 1627 1363 is a "BCD to Decimal 
Decoder/Driver." The 849 1627 1371 is a "Counter/Storage Register." 
Fortunately Signetics datasheets still exist here 
(http://bitsavers.org/pdf/signetics/_dataBooks/1972_Signetics_Full_Line.pdf). 
It appears that the 906 (BCD to decimal decoder/driver) is equivalent to a 
Signetics 7441 (page 2-40) and the 849 (counter) is equivalent to a 
Signetics 8280 (page 3-90). So I think I've found all the features of the 
BIP-8820-1 along with the pinout. 

I'll post the schematic and pinout soon after I do a good test.

Thanks for the tips!

~clu

On Sunday, 11 March 2012 20:38:04 UTC-6, nixiebunny wrote:
>
> On 3/11/12 5:12 PM, clu wrote:
> > I found two old Signetics chips in there. The Signetics logo is the one
> > used in the late 60s but I can't find any data using the part numbers on
> > the chips. Can anyone identify these chips (image links below)(I'm
> > assuming one decade counter with BCD output and a nixie driver)? I'd
> > like to make an unofficial BIP-8820 datasheet for anyone else out there
> > with these...
> >
> > http://i.imgur.com/V2Cos.jpg
> >
> > http://i.imgur.com/3nn1i.jpg
> >
>
> Those are definitely Burroughs house numbers, since the number on the PC 
> board under the chip in the second photo has a number with the same format.
>
> Good luck on the reverse engineering!
>
> -- 
> David Forbes, Tucson AZ
>
>

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