26 Dec
2006
26 Dec
'06
3:58 a.m.
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