Fairchild 960 BCD Decoder pin out information help - UK Vintage Radio Repair and Restoration Discussion Forum

ctc15 · 7th Oct 2022, 9:28 am

Hi All
l have some Fairchild 960 BCD Decoder chips which l would like to use in a Nixie clock.
l have been looking for the pin out information without success l hope someone can help with with this information.
l hope to repeat making a clock l made in 1971 from scrap counter parts.
Thanks
Keith

Keith956 · 7th Oct 2022, 10:43 am

I found this in the back of a Fairchild TTL data book I have. No other info on these devices though, just the pinout.

ctc15 · 7th Oct 2022, 12:45 pm

Hi Keith Thank you for the scan unfortunately l cannot read the pinout information could you send the pinout as 1>0v etc

Thanks
Keith

Keith956 · 7th Oct 2022, 12:52 pm

Sorry about that, the image must have been compressed when it was uploaded. Here's the pinout:

1 = Z9
2 = Z7
3 = Z5
4 = Z3
5 = Z1
6 = I1
7 = I2
8 = GND
9 = Z0
10 = Z2
11 = Z4
12 = Z6
13 = Z8
14 = I8
15 = I4
16 = VCC

Ed_Dinning · 7th Oct 2022, 4:12 pm

Hi Keith, a quick check against the popular 74141 decoder drive reveals it has a different pinout.
For low frequency use I suspect they would interchange apart from the base pin out

Ed

factory · 7th Oct 2022, 5:52 pm

They will not interchange the 74 series, apart from the different pinout, the Fairchild part uses negative logic, i.e. requires four logic high inputs to display zero, they were commonly used on a +3.6V supply too.

I would advise against using them, due to the difficulty in finding them for restoring old test gear, I certainly haven't got any spares for my test gear if any fail.
I would suggest using the USSR equivalent to the 74141 as they are easier to obtain, or a current production "BCD to decimal decoder" IC (74 or 4000 series) and HV driver transistors for the tubes.

David

ctc15 · 7th Oct 2022, 9:32 pm

Hi Factory Thank you for the information l had forgotten that that l used a 958 ? to drive them.
I just found an old st bruno tin from the 1970s with a lot of old chips in it 960 , 9093-9 , 9359 , 958 , T102 D1 are these any use to you?
Keith

factory · 9th Oct 2022, 1:34 pm

The 958 is the decade counter, 959 is the storage latch in the same series, the 9093 is a dual JK flip flop.

The 9359 is a TTL BCD to 7 segment decoder, the Fairchild databook gives 5449 & 7449 as the same.

Not 100% sure I've correctly identified the T102-D1, found a reference to a TTL quad Nand gate for T102D1-14 in the 1974 D.A.T.A. IC databook.

And yes I would be interested in these.

David

7th Oct 2022, 9:28 am	#1
ctc15 Pentode Join Date: Oct 2005 Location: Barnet, London, UK. Posts: 167	Fairchild 960 BCD Decoder pin out information help Hi All l have some Fairchild 960 BCD Decoder chips which l would like to use in a Nixie clock. l have been looking for the pin out information without success l hope someone can help with with this information. l hope to repeat making a clock l made in 1971 from scrap counter parts. Thanks Keith

7th Oct 2022, 10:43 am	#2
Keith956 Heptode Join Date: Jun 2019 Location: Oxfordshire Posts: 740	Re: Fairchild 960 BCD Decoder pin out information help I found this in the back of a Fairchild TTL data book I have. No other info on these devices though, just the pinout. Attached Thumbnails

7th Oct 2022, 12:45 pm	#3
ctc15 Pentode Join Date: Oct 2005 Location: Barnet, London, UK. Posts: 167	Re: Fairchild 960 BCD Decoder pin out information help Hi Keith Thank you for the scan unfortunately l cannot read the pinout information could you send the pinout as 1>0v etc Thanks Keith

7th Oct 2022, 12:52 pm	#4
Keith956 Heptode Join Date: Jun 2019 Location: Oxfordshire Posts: 740	Re: Fairchild 960 BCD Decoder pin out information help Sorry about that, the image must have been compressed when it was uploaded. Here's the pinout: 1 = Z9 2 = Z7 3 = Z5 4 = Z3 5 = Z1 6 = I1 7 = I2 8 = GND 9 = Z0 10 = Z2 11 = Z4 12 = Z6 13 = Z8 14 = I8 15 = I4 16 = VCC Attached Thumbnails

7th Oct 2022, 4:12 pm	#5
Ed_Dinning Dekatron Join Date: Jan 2004 Location: Newcastle upon Tyne, Tyne & Wear, UK. Posts: 8,195	Re: Fairchild 960 BCD Decoder pin out information help Hi Keith, a quick check against the popular 74141 decoder drive reveals it has a different pinout. For low frequency use I suspect they would interchange apart from the base pin out Ed

7th Oct 2022, 5:52 pm	#6
factory Octode Join Date: Jul 2009 Location: Cheshire, UK. Posts: 1,738	Re: Fairchild 960 BCD Decoder pin out information help They will not interchange the 74 series, apart from the different pinout, the Fairchild part uses negative logic, i.e. requires four logic high inputs to display zero, they were commonly used on a +3.6V supply too. I would advise against using them, due to the difficulty in finding them for restoring old test gear, I certainly haven't got any spares for my test gear if any fail. I would suggest using the USSR equivalent to the 74141 as they are easier to obtain, or a current production "BCD to decimal decoder" IC (74 or 4000 series) and HV driver transistors for the tubes. David Attached Thumbnails Last edited by factory; 7th Oct 2022 at 6:06 pm.

7th Oct 2022, 9:32 pm	#7
ctc15 Pentode Join Date: Oct 2005 Location: Barnet, London, UK. Posts: 167	Re: Fairchild 960 BCD Decoder pin out information help Hi Factory Thank you for the information l had forgotten that that l used a 958 ? to drive them. I just found an old st bruno tin from the 1970s with a lot of old chips in it 960 , 9093-9 , 9359 , 958 , T102 D1 are these any use to you? Keith

9th Oct 2022, 1:34 pm	#8
factory Octode Join Date: Jul 2009 Location: Cheshire, UK. Posts: 1,738	Re: Fairchild 960 BCD Decoder pin out information help The 958 is the decade counter, 959 is the storage latch in the same series, the 9093 is a dual JK flip flop. The 9359 is a TTL BCD to 7 segment decoder, the Fairchild databook gives 5449 & 7449 as the same. Not 100% sure I've correctly identified the T102-D1, found a reference to a TTL quad Nand gate for T102D1-14 in the 1974 D.A.T.A. IC databook. And yes I would be interested in these. David