Sound chips

From: Richard Erlacher <>
Date: Fri Jun 15 10:30:43 2001

I've got a salvaged "set" if you can call it that, of the NSC Digitalker chips,
i.e. a 40-pin "B218DIGITALKER" and a ROM presumably designed for the specific
application, which, in this case, was a security system, for which this device
was the telephone interface that called the authorities or someone when an
intrusion was detected. I once intended to use it for something similar to what
was done with that SPO256 speech chip that Radio Shack made popular, but didn't
get around to it.

If anyone's interested, I'll happily send the pair + associated 4 MHz crystal,
to whoever wants to pay the postage. (USPS Priority Mail = $3.50).

This was part of a microcontroller (COP444L) based board that had an RF
interface common in many building-security systems of the early '80's working
not unlike a garage door opener, and a built in phone-line interface, though no
modem was needed since the interface was audio. These boards all had a common
flaw, i.e. a capacitor in the phone line interface that was broken open. That
presumably had no effect on the integrity of the voice generation circuitry, as
it was buffered with an LM386 amplifier.

----- Original Message -----
From: "Alice Blakeman" <>
To: <>
Sent: Friday, June 15, 2001 7:40 AM
Subject: RE: Sound chips

> They may very well still sell it. I built a parallel port speech sythethiser
> from one and plans from one of the then popular computer or electronics
> magazines. I may even have it still in one the boxes that I packed way back
> and haven't since opened. It had the same phonetics system as some of the
> SoundBlaster chips and had the same monotone speak that the old Dr. SBaitso
> and that Hawkings' synth have. Nonetheless it was cool to hear speech from
> my 8088 then.
> -----Original Message-----
> From:
> []On Behalf Of Richard Erlacher
> Sent: Friday, June 15, 2001 7:48 AM
> To:
> Subject: Re: Sound chips
> Back in the early '80's they sold that speech chip in a blister pack. I
> think
> the crux was getting the 3.12 MHz (I remember that only because getting one
> was
> such a PITA) crystal, though, for which the device was specified, and which
> had
> to come from somewhere else at the time. Aside from having to translate the
> timing intervals, I think a color-burst crystal would probably work with
> this
> device, though. A 10-12% increase in pitch wouldn't make much difference as
> far
> as intellibility is concerned.
> Dick
> ----- Original Message -----
> From: "Jeff Hellige" <>
> To: <>
> Sent: Thursday, June 14, 2001 6:55 PM
> Subject: Re: Sound chips
> > >Incidentally, Tandy/Radio Shack sold a speech/sound cartridge for the
> > >CoCo. It contained a microcontroller, an SPO256 speech chip and an
> > >AY-3-891x sound chip.
> >
> > Didn't they sell the SPO256 alone, among all the other single
> > IC's? I know that even recently I've seen their 'speech chip' on the
> > shelf but have never bothered to notice exactly who's chip it is.
> >
> > Jeff
> >
> > --
> > Collector of Classic Microcomputers and Video Game Systems:
> > Home of the TRS-80 Model 2000 FAQ File
> >
> >
> >
Received on Fri Jun 15 2001 - 10:30:43 BST

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