The original chip is custom programmed during manufacture. You'd have to find one that had actually been pulled working from a Pro-One..
Basically impossible to find..that's why this guy developed a replacement and whilst doing it added new features.
From: Nicolas
To: vintagesynthrepair@yahoogroups.com
Sent: Friday, 16 August 2013, 21:20
Subject: [vintagesynthrepair] Re: Sequential Circuit Pro One UPD8021 chip
To: vintagesynthrepair@yahoogroups.com
Sent: Friday, 16 August 2013, 21:20
Subject: [vintagesynthrepair] Re: Sequential Circuit Pro One UPD8021 chip
Hi,
I sent him a message and I think it's the same guy. He's on vacation too.
The price is 120$ + shipping which seems a little bit high to me.
I'd like to find the original chip if it's still possible.
The number written on the chip is D8021C and it was made by NEC.
Thank you!
Nicolas
--- In vintagesynthrepair@yahoogroups.com, "grantpbt" wrote:
>
> The seller is on vacation, but more info here: www.musictechnologiesgroup.com
>
> GB
>