Any info on this old speech chip? - Page 1
Forum section: electronics / general

author: jasonlbarrett
author_rank: Newbie
timestamp: August 15, 2017, 01:40:06 am
content: Hello,I have used the General Instruments SP0256A-AL2 and I've learned that there's several variants of it out there like the -012 and -017 but I've come across an SP0256A-053 and I can't find a thing about it anywhere. I guess I could just go through and send signals and see what it says but that sounds like work. If anyone has any info or can lead me in the right direction I would greatly appreciate it.

author: albert22
author_rank: Regular Contributor
timestamp: August 15, 2017, 04:37:14 pm
content: The datasheet is easy to find in googlehttp://bitsavers.trailing-edge.com/pdf/gi/speech/General_Instrument_-_SP0256A-AL2_datasheet_%28Radio_Shack_276-1784%29_-_Apr1984.pdfThis is the same DS that I got more than 20 years ago when I put this chip to work.Dont expect too much of it it really sucks at speaking.

author: CJay
author_rank: Super Contributor
timestamp: August 16, 2017, 03:57:53 pm
content: No, it might actually be a different chip, some of the SPO256 chips were programmed with different allophones and even phrases, some were designed for use in speaking clocks for instance.The 'sucks' is relative, at the time it was designed it was pretty awesome, I built a VIC-20 speech synthesizer with one in, one of my very first ever kit builds and it was amazing, must have been about 13 at the time.

author: jasonlbarrett
author_rank: Newbie
timestamp: August 16, 2017, 08:29:22 pm
content: Yeah, it says "SP0256A-053". I've been playing around with the AL2 version for a little while and I like how it sounds. I'm going to send some juice to it and just see what it says. I can't even find a mention of it.

author: albert22
author_rank: Regular Contributor
timestamp: August 16, 2017, 09:15:26 pm
content: The IC that I used (shown in the photo) is marked as SPO256A-AL2 1981GI. I bought it at Radio Shack and came in a blister with the "Archer" data sheet that I linked.It should have the same interface and then the allophones could be determined by trial and error.QuoteThat was more than 20 years ago, may be my memory is failing or I didnt implement it well enough.I still have the board so I might give a try when time permits.

author: CJay
author_rank: Super Contributor
timestamp: August 16, 2017, 09:52:24 pm
content: Quote from: albert22 on August 16, 2017, 09:15:26 pmWell that's very kind of you but it's more like 35 years ago...I've got a small board here with an SPO256 on it but it sounds nothing like the VIC20 one I built.This is the one I built:https://www.retrocomputers.online/2011/06/vic-20-talk-back-maplin-gb17t-lk00a/and this is the one I have nowhttp://www.hewittboys.com/jimboh/jim/spo256/spopcb.htm

author: Shred
author_rank: Contributor
timestamp: August 17, 2017, 01:33:50 am
content: Wow: that brings back some memories.There was a matching mask-programmed microcontroller (an 8051, I think?) that would take in plain text, convert it to allophones and drive the sp0256 for you. I had the matching pair lashed up on veroboard and connected to the printer port. "lprint 'Hello world' " would result in it speaking "hello world". Much better than having to lookup the allophones. Ask it to say "yacht" and it would come out with something quite different, so it was far from perfect.The microcontroller had a similar part number to the sp0256, but was distinguished by being in a 40 pin DIP package.

author: edavid
author_rank: Super Contributor
timestamp: August 17, 2017, 02:53:20 am
content: Quote from: Shred on August 17, 2017, 01:33:50 amThat was the CTS256A-AL2. Of course it was not an 8051 - GI did not make those - it was a PIC.