88-ACR KCS modification

[Allison]

>
>Subject: 88-ACR KCS modification
>   From: Grant Stockly <grant at stockly.com>
>   Date: Mon, 25 Dec 2006 14:00:27 -0900
>     To: cctalk at classiccmp.org
>
>I'm trying to modify my 88-ACR to work with the KCS specification.
>
>Does anyone know where the information on modifying the 88-ACR to 
>read/wrote KCS audio is?
>
>Also, I was wondering if anyone ever looked at this card?  The XR210 chip 
>MITS used for demodulation of the FSK signal is capable of MODULATING 
>too.  (with both mark and space frequencies).  Does anyone know why they 
>would have used 5 ICs and a few opamps to do the modulation when they could 
>have used the other half of a chip already present?
>
>Grant 

Not possible.  The ACR is simple FSK and the KCS is redundent FM.

As to the latter question of component use... the ACR was intended as a 
modem (bell 103) and it's design was based on that.

Allison