Date: 19951201 From: Paul Grohe Organization: National Semiconductor Newsgroups: sci.electronics.repair Subject: Help wanted on special IC Richard Rasker from University of Twente, Enschede, The Netherlands thoughtfully inquired: > I've got an ancient (probably mid-70's) solina string ensemble keyboard with > an IC that I can't find in any databooks. > The device has the number M 087 B1, and my guess is that it's a special > divider chain; it takes 1MHz as an input and on the PCB there are markings for > each tone in the scale, (C, C#, D, Eb..etc) on 12 of its pins. > I'm afraid that this device is broken, since there is an input signal of 1MHz, > but nothing comes out.. Does anybody have any data on this, or knows where > this device might still be obtained? > Thanks in advance! > Richard Rasker > Calslaan 54-11 > 7522 MG Enschede > tel. +31-(0)53-4350834 Which pins are marked? I am looking at a diagram for a S50240 "Top Octave Synthesizer" (in 1980 Engineers Notebook by Forrest Mimms) that may be a possibility. S50240 Top Octave Synthesizer Pin Desc 1 V+ (12V) 2 Osc in (Tones shown are for 2MHz, drop one octave for 1MHz) 3 GND 4 C8# /451 5 D8 /426 6 D8# /402 7 E8 /379 8 F8 /358 9 F8# /338 10 G8 /319 Outputs 11 G8# /301 12 A8 /284 13 A8# /268 14 B8 /253 15 C8 /239 16 C8 /478 Does this look like it? If so, I may have this chip floating around somewhere. Regards, Paul Grohe --------------------------------------------------------------- Paul Grohe National Semiconductor Corp. Sr. Electronics Technician 2900 Semiconductor Drive AMPS New Products Eng Group Mail Stop C2693 Santa Clara, CA. 95052-8090 USA (408) 721-7389 Tel (408) 721-2513 Fax For technical assistance, literature, or samples call Canada & US: (800) 272-9959 Europe: (49) 814 110-3720 Email Support: NSC datasheets online at: http://www.natsemi.com Usenet Disclaimer: Any opinions expressed are mine, not NSC's ---------------------------------------------------------------