COMPLEX SOUND CHIP 76477

[MrDEB]

yea I know this is an ancient chip but have always wanted to build something using one but chips are readily available but in an Sdip package unless I purchase 57 chips from a guy in Argentina!!
Well locating an Sdip socket is pretty much a wash unless I purchase for $12 one socket.
Before I go much further as I have an adapter PCboard designed and a PC board for a sound demonstration is there any interest in such a PC board.
My goal is a device I will call GRANDPAS REVENGE as this is a Christmas gift for two grand sons.
Has anyone built such a device and / or purchased chips from Hong Kong as per Ebay.
Any interest in such a PC board and / or adapter board so an Sdip chip can be used in a bread board.
A schematic is available upon request using Diptrace.

 

[canadaelk]

I believe it would be cheaper to use an ISD sound recorder (like the ISD1420P) IC. E

 

[MrDEB]

With the chip you suggested is very limited. Can't do what the 30 year old 76477

 

[MrDEB]

YES I am finally getting settled in my new digs in Washington state. Have all of the electronics stuff still in boxes but will start unpacking soon. LittleGhostman is too young to know about the 76477 or the 76488 sound chip. Radio Shack in their heyday when they sold lots of electronic parts sold this chip.They sold a couple of versions of the Engineers Notebook that I have two versions and both have several pages concerning the 76477 so the chip can't be all that bad.. In fact while searching Ebay there was an unopened 76477 from RS that I should have snagged. Have two chips but they are the Sdip and sockets are few and expensive. Going to breadboard what I have and go from there.
I wondered if a Thermin combined with the 76477 is doable or ??
Just thinking outside the box.

 

[atferrari]

Hola MrDB
I am not who sold/is selling them to you but I got some 76477 and if I recall it right, 76481.

The first I used it for testing different sounds using the setup suggested in the datasheet? provided by RS.

Once used to the concepts of A D S R, I became productive.

Few years ago I revisited them to show my modelist brother that the sound of steam locomotive could be imitated somehow.

Even I considered using a simple micro to produce preprogrammed sounds but no having a real use in mind I discarded it.

 

[JimB]

I have tidied this thread by deleting the un-necessary off-topic chaff.

JimB

 

[MrDEB]

Here is the basic schematic I am using with an addition of a push pull amp and a pot to adjust the 555 output.
https://experimentalistsanonymous.c...76477 Single Chip Synth Corrected Diagram.jpg

 

[large_ghostman]

Shouldnt there be a resistor between s6 and pin9 to limit current? same with pin 1 and 28. Havnt checked the datasheet though.

EDIT
Apparently not!

 

[MrDEB]

Good question Little Ghostman but the data sheet says no.
here is the schematic I am actually using with Diptrace. All the switches are SPDT (all the little boxes) for ease of drawing out the schematic. All the switches and rotary switches are to be mounted on a panel as no PCB is needed except maybe to mount all the caps and resistors. Originally had all on same board but a lot more jumper wires so the PCboard is now utilizing ribbon cable. Hopefully people can read this if interested.

 

[large_ghostman]

I read the sheet after posting hence the edit, I was surprised considering the age of the chip that the data sheet dosnt show resistors! I guess I am used to newer ones, having said that I might see if I can get hold of one of them chips, it would have been useful for the music gun thing I made, the chip kind of strikes me like a bunch of 555 timers in a compact package.

Apparently some thought the pic I posted etc was a dig at you, I hope you took it the way I intended you take it, as a welcome back blah blah blah, also the whitehouse comment was more about you know what than anything and hopefully you laughed as much as I intended you too . Problem is many dont know what goes on in email etc .

NOT that you should change it but I cant see the diagram well on the dark background!! I have glasses now but I find that combination difficult to read, just a heads up.

 

[AnalogKid]

What is an Sdip package? Not DIP, not SIP, not SO ...? If you mean SIP, those sockets are pennies. If you mean skinny DIP, as in 28 pins but only 0.3" wide, they start at 33 cents at DK:

https://www.digikey.com/product-sea...dip+socket&quantity=&ptm=0&fid=0&pageSize=500

ak

 

[MrDEB]

I know the background needs to be white but still can't read the part numbers etc. Ran into this issue long ago but ? I saved it in png and jpeg but no real difference.
As to the chip package, it is an unusual package with 1.7 pitch and not the usual 2.54 pitch. Digi key has but for $12 each.
As to the whitehouse comments, I never take any comments seriously but I and my wife love popcorn.
Will try a different approach to posting the schematic and the PCboard layout unless you have Diptrace then I can just upload the files and people can build to their hearts content. The main board is 2.4 x 4 inches and can get 10 for around $23.
Note to Little Ghostman, this chip was used in arcade games, mainly space invaders.

 

[large_ghostman]

I know the background needs to be white but still can't read the part numbers etc. Ran into this issue long ago but ? I saved it in png and jpeg but no real difference.
As to the chip package, it is an unusual package with 1.7 pitch and not the usual 2.54 pitch. Digi key has but for $12 each.
As to the whitehouse comments, I never take any comments seriously but I and my wife love popcorn.
Will try a different approach to posting the schematic and the PCboard layout unless you have Diptrace then I can just upload the files and people can build to their hearts content. The main board is 2.4 x 4 inches and can get 10 for around $23.
Note to Little Ghostman, this chip was used in arcade games, mainly space invaders.

There should be loads around then!! Glad you like popcorn I have loads to sell . I only like it with butter on .

I wonder why the strange pitch? The size is ringing a bell for some reason i will look and see if I know a decent cheap source


EDIT

The width is 10.16mm apparently there were 2 widths. And apparently its 0.4mm pitch??

 

[MrDEB]

the chip I have in hand has a 1.7 pitch. I created a pattern for it in Diptrace and printed it out. Perfect!!.As for chips there are lots but their counterfeit I am pretty sure. I think TI only had the wide spacing between pin rows.

 

[large_ghostman]

I got it from wikipedia but I think they are using the wrong measurement

 

[MrDEB]

Well I stand corrected, there are appearently two different pin layouts.
here are the two different listings I just copied n pasted from Ebay Learn something new every day
SN76488 SN76488N SN76488NF Sound Generator IC, 1pcs

It is over 20 years old/used IC, NOS, refer to the picture

This item SN76488NF equals SN76477+Audio Amp. and selling as-is.

Please note the package is standard SDIP-28 (28pin, 400 mils width, and 1.778mm pitch).

Free shipping by air-mail.

You will receive 57 unused SN76477-NF ICs.

Format: SDIP 28 Pin 0.4 inch 10.16 mm width.

Made by Texas Instruments in 1983.

I have bought this lot years ago, but never used them.
All NOS ICs, not pulled, not used.

-- THESE ARE NOT Fakes or Counterfeits --

 

[MrDEB]

Well here are the compressed files for the schematic and PCboard in Diptrace

 

[jpanhalt]

Does DipTrace allow printing to a PDF? That is a standard feature of some programs, such as Eagle, and it allows almost everyone to see them without installing DipTrace.

John

 

[large_ghostman]

I remember a long thread on your woes with dip trace and getting a clear picture, if you have it doing a clear pic then leave it alone , I think the ones you have were less common but are more common now.

 

[MrDEB]

Yes I remember but don't recall getting a clear pic. I think I had to change the font on all the parts?
And no I don't see a pdf export.
Really wondering if this gizmo is worth the time BUT with 7 rotary switches, 13 pots and 15 switches it will keep the grand-kids busy for hours. Just wish I could locate an inexpensive socket for the chip. Got a great deal on Ebay for all the SPDT switches for $5 including mounting hardware.