Datasheet for SN76488N

openfly · Joined: Aug 17, 2008 Posts: 2 Location: NEW YORK CITY

I have an SN76488N and I want to use it for a project... but there are no datasheets anywhere on the internet. I saw it posted to a forum here, but the download link is now dead.

I would be extremely grateful if someone were to share with me that datasheet.

Please help me electro-music... you're my only hope.

-matt

andrewF · Posted: Sun Aug 17, 2008 5:51 pm Post subject:

here you go
build something nice!

76488.pdf

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openfly · Joined: Aug 17, 2008 Posts: 2 Location: NEW YORK CITY

Awesome! Thanks a bunch!

achillies · Joined: Mar 15, 2019 Posts: 5 Location: Aurora, Il

This datasheet is bad.. just plain wrong. There is another example of this same bad pinout in the 1980 Engineers handbook, which shows the SN76488 as being the same as the SN76477, with the exception of audio input and an internal amplifier. THAT BOOK IS WRONG, and resulted in me personally toasting a few of those 88 chips. The 1982 edition has a corrected schematic for the SN76488N, showing that GROUND IS PIN 14 and VCC input on pin 12! The 77 has +VCC on pin 14 and ground on pin 2. Not the same at all, and there are a bunch of other differences.

The 1982 edition with good pinouts and a few projects is here -> http://www.achillies.com/Project_files/img/engineers-notebook-ii-a-handbook-of-integrated-circuit-applications-forrest-mims.pdf

A comparison pinout is here -> http://www.achillies.com/Project_files/img/sn76477_sn76488_pinout.png

achillies · Joined: Mar 15, 2019 Posts: 5 Location: Aurora, Il

I know this is an old thread, and I'm probably talking to myself, but I was trying to find a pdf of the REAL datasheet for the SN76488, but have yet to find one. There are a few images floating around that are definitely scanned from the original, but I have yet to find a copy with all of the pages/panels.

I DID find one more old magazine article though, and this one is pretty thorough. Page 69 of Jan 1984 Radio Electronics, believe it or not.

https://www.americanradiohistory.com/Archive-Radio-Electronics/80s/1984/Radio_Electronics_January_1984.CV01.pdf

If someone has a hardcopy of that old SN76488N, PLEASE share it.. sometimes there are tidbits of info on those sheets if you read between the lines. The preliminary version just doesn't cut it (and has some bad info)

cementimental · Joined: Jun 07, 2011 Posts: 14 Location: London

Here's a scan of an old sci-fi filmmaking magazine which contains plans for a SN76488-based sound fx box - the article says that the datasheet has errors anyway (as others have mentioned above) and that their schematic is better! https://archive.org/details/CineMagic018/

achillies · Joined: Mar 15, 2019 Posts: 5 Location: Aurora, Il

That's a great article to add to my collection. I bought my SN76488N's back in the early 80's, and I actually remember buying them. I bought two, both were in the clearance bin, and neither had datasheets. I wonder if the bad datasheets were pulled by radio shack or TI, and that's what relegated these (the only ones they had) to the clearance bin.

Incidentally, I just finished my 76488 Demo pcb (based on the demo box from that radio electronics article, with differences on one shot logic and external vco control, which were taken more from the sn76477 datasheet). Here's a pic.

2019-03-20 19.09.06.jpg

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PCBs for the SN76488 and SN76477s

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cementimental · Joined: Jun 07, 2011 Posts: 14 Location: London

No probs

I've been hoarding info about these things for a while, got mine on ebay some time ago (plus a couple of 77s) and really need to get round to building something

those look great!

MusicMan11712 · Posted: Tue Apr 02, 2019 3:43 pm Post subject: Re: Another SN76488 project

achillies · Joined: Mar 15, 2019 Posts: 5 Location: Aurora, Il

Thanks for posting. It sounds like we had similar pasts, because I've got the original datasheet(s) for my 77's as well. I also have originals for the SN94281 and SAD1024 chips, but I think those are easily found on the internet as well (the datasheets, not necessarily the chips, even though I do have an sad1024 still in the original package).

Ayab · Joined: Oct 27, 2015 Posts: 186 Location: London, UK

Thank you Achilies for linking to the Forest Mimms IC applications handbook that is really useful.

Hey Cementimental that Cinemagic soundbox article is excellent.

Achilies your pcb adapted from the soundbox looks great - it would probably save me a great deal of frustration if you would kindly share your layout Wink

Btw AchillesI recently read Delton Horn and recognise the comparison pinout page you linked to - have you seen his SN76488 example sound effect generator (fig. 3.79) - attached.

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achillies · Joined: Mar 15, 2019 Posts: 5 Location: Aurora, Il

Ok, here are my PCB layouts and silkscreens for both chips. I have yet to actually populate the boards and test either, so use at your own risk, and be sure to check all of the traces.

SVG files are not allowed, so these were saved as PNG files. Make sure to verify spacing, etc..

If you need the svg files, let me know, and I can post them on my website for download.

76488_pcb.png

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76477_pcb.png

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MusicMan11712 · Posted: Sat Apr 13, 2019 9:17 am Post subject:

Nice!!! Thanks for sharing. Maybe this will inspire me to do something with my SN76477. It was moved from the back burner to the deep freezer decades ago, but it might be worth testing to see if it survived.

When Radio Shack closed most of its stores (all of them?) a few years ago, I picked up the "Electronic Learning Lab" for something like 80% off the list price (the one with two 8.5 x 11 Forrest Mimms Workbooks--reminders of the little books from ages ago which you can find on line).

The 555 LED test circuit on there has been collecting dust long enough. If I do replace it with the SN76477, I will owe you big thanks for reminding me of the chip!!

Steve

ickystay · Joined: Nov 15, 2006 Posts: 143 Location: Oregon

Ayab · Joined: Oct 27, 2015 Posts: 186 Location: London, UK

Yes - Thank You achilles and others.

Sorry for the delay in saying this - That is very kind and generous. I am at a bit of a diy impasse (long story) at the moment but hope to have things sorted out and will be building again soon.

Sending you good vibes

Hope it is helpful to post the schematic and relevant pages from the Radio Electronics magazine

(That 1984 Radio Electronics magazine is so interesting and I am so easily distracted!! I also included the next article on transistor switches to remind myself to read it properly!) Very Happy

76488 Sound Gen Schema.png

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SN76477-88 Sound Gen - RE Jan'84.pdf

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Ayab · Joined: Oct 27, 2015 Posts: 186 Location: London, UK

Hey achilles

Am nearly ready to try etching your SN76488 Sound Generator PCB Very Happy

Can you just first please explain to me what the ground connections next to the Noise, Decay and VCO capacitors. To switch them off?

I have highlighted them in green so you know what I am asking about.

Hope you are having a good weekend Very Happy

Achilles 76488 Grounds.jpg

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orby · Joined: Jan 04, 2024 Posts: 2 Location: NW UK

ickystay · Joined: Nov 15, 2006 Posts: 143 Location: Oregon

Here.

Cinemagic 18.pdf

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SN Article

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orby · Joined: Jan 04, 2024 Posts: 2 Location: NW UK

supermmxx · Joined: Jan 21, 2025 Posts: 2 Location: Cologne

Dear colleagues,

in the 80s in my school time I worked in a Tandy Radioshack Shop in Cologne. I got tons of electronic components in these time and kept the datasheet for this IC I still have.
Today I scanned in the original datasheet.
For you folks, here it is - my first contribution.
Best regards,
supermmxx

ARCHER - TECHNICAL DATA - SN76488N Complex Sound Generator - Catalog Number 276-1766 EN.pdf

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SN76488N datasheet

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blue hell · Posted: Wed Jan 22, 2025 5:09 am Post subject:

supermmxx and thanks for the datasheet Exclamation

I did edit out the duplicates though Laughing

supermmxx · Joined: Jan 21, 2025 Posts: 2 Location: Cologne

Thank you,

for information here are two other datasheets I scanned today from my 35 years old bureau folders. I don't know if they match here but feel free to move this attachments to the right topics.
Best regards,
supermmxx

ARCHER - TECHNICAL DATA - SN76477N Complex Sound Generator - Catalog Number 276-1765 C OCR EN.pdf

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ARCHER - TECHNICAL DATA - PCIM-161R LCD Clock Module - Catalog Number 277-1005 OCR EN

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ARCHER - TECHNICAL DATA - PCIM-161R LCD Clock Module - Catalog Number 277-1005 OCR EN.pdf

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ARCHER - TECHNICAL DATA - PCIM-161R LCD Clock Module - Catalog Number 277-1005 OCR EN

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