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REQ - 1970s shift registers sought

Hello

I'd like to buy some rather elderly PMOS shift registers. Does anyone have any on an old board or can you advise me how to source them please? Internet searches have found nothing.

Back in the 70s, MSI manufactured the MF7104 (and possibly the MF50052T).

The only details I can give are thus:

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Part Number = MF7104 Manufacturer Name = Microsystems International Ltd Description = 128 to 250 Bit Shift Register Bits Per Reg. = 128 No. of Reg. = 2 Data Inp Mode = Serial Data Outp Mode = Serial f(oper) Max. (Hz) = 2.0M t(PLH) Maximum (S) = 300n Mode Dyn/ Stat = Static P(D) Max.(W) Power Dissipation = 500m Vsup Nom.(V) Supply Voltage = 5.0 Status = Discontinued Package = TO-100 Pins = 10 Technology = PMOS

They are ten legged devices in a TO-100 can (similar to a metal TO-5 transistor package).

I don't know what computer hardware they may have formed part of, but I need them for a 1970s digital sequencer which forms part of a rare (ish) music synthesiser, an EMS synthi-AKS.

if anyone can help, please could they post a message in reply?

Thanks

RMC, England

Reply to
RMC
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I am reasonably sure we used the MF7104 in the mid 70s but had many problems. The chips would suddenly become dynamic (only operated as long as we kept clocking them fast enough). Some failed all together. I suspect the circuit synthesiser forms part of some form of digital delay-line. I would recommend trying to substitute something such as the MC14517, CD4517 or HFE4517. It will require some redesign on your part to make the parts fit, probably cascade more than one, but it might be worth the effort.

To get a specific (non binary power) shift-register length the CD4006 - multi-tap 18-bit shift-register might be of help. It seems if both these ICs are still in active production at TI.

Regards Gerhard van den Berg CSIR

Reply to
Gerhard

Gerhard - many thanks for this response. I agree that a modern equivalent would be the best solution and I may start looking into just that.

Cheers for your help

RMC, England

Reply to
RMC

Somewhere I've got a tube of perhaps 50 shift registers. IIRC they are of similar vintage may be 1 K bit long - package is 8 pin DIP. I think they were National Semiconductor parts. A quick look has failed to locate them. If you want me to search further let me know - might take a while though!

--
Jim Backus running OS/2 Warp 3 & 4, Debian Linux and Win98SE
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Jim Backus

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