Radio Shack/Archer Code to Speech

I had some old Radio Shack/Archer speech processing chips lying around that I’d been wanting to play around with for quite some time. So, I began by bread-boarding them and then designed a PCB layout in Eagle. The chips used are the CTS256A-AL2 and SP0256.  The data sheets for these chips are pretty old and hard to read but I was able to decipher enough out of them to get the circuit working.

CTS256A-AL2 data sheets:

• CTS256A-AL2 Code-to-Speech Processing Chip

SP0256 data sheets:

• SP0256 Narrator Speech Processor
• Archer SP0256-AL2
• sp0256a
• SP0256B_Datasheet
• SP-0250_Datasheet
• SP0250_Applications_Manual

I used Eagle to develop a schematic based on the data sheets but omitted the audio amplifier since I was using an external one and couldn’t seem to get satisfactory performance from the circuit used in the data sheets.