Path: utzoo!news-server.csri.toronto.edu!cs.utexas.edu!uunet!microsoft!kentsu
From: kentsu@microsoft.UUCP (Kent SULLIVAN)
Newsgroups: comp.sys.cbm
Subject: Re: SwiftLink 232 + other carts
Message-ID: <71211@microsoft.UUCP>
Date: 12 Mar 91 01:00:00 GMT
References: <9103050059.AA15734@cwns9.INS.CWRU.Edu> <1991Mar5.135550.5053@news.nd.edu> <71099@microsoft.UUCP> <1991Mar9.211859.20933@news.nd.edu>
Reply-To: kentsu@microsoft.UUCP (Kent SULLIVAN)
Organization: Microsoft Corp., Redmond WA
Lines: 39

In article <1991Mar9.211859.20933@news.nd.edu> treesh@bach.helios.nd.edu writes:
>Thanks for the help Kent.  My hopes that the ribbon cable wont cause too  
>much of a problem with reguards to the noise getting into the circuit.
>Keepiing the lenght short as possible should help a lot.

Let us know how well the ribbon cable works.  It seems to work ok for Matt
Desmond, but that could just be "dumb luck" <GRIN>.  (No offense, Matt!)

>Beause the REU is stuck at address $DF00 in I/O, and the SwiftLink is at the
>other address, there should be no conflicts, but that completely rules out
>the use of the Lt Kernal Hard Disk Drive along with these two devices, since
>the Lt Kernal host adapter is also switchabe, but only two pages of I/O
>are avaliable, and both woud be taken.

Well, that depends.  If you're using this stuff on a C-128 (in *any* of the
modes: C-64, C-128, or CP/M), there is a third I/O slot available--$D700.
The reason for this is CBM fully decoded all the I/O pages in the C-128 since
they had to have room for the 8563 VDC and the MMU.  On a C-64, the I/O block is
not fully decoded, as you can tell by references to "SID mirrors".

I believe Fred Bowen mentioned once that $D700 was to be the "home" for
CBM's own SwiftLink-type device for the C-128... which was never released,
of course.  Memory maps in the C-128 PRG list $D700 as reserved for the future.

You can use the SL at $D700 by cutting the jumper and not reattaching it to
either $DE00 or $DF00 then running a clip lead into the computer... I can
post the exact chip & pin numbers if anyone is interested.

Most of the current software which supports the SL can be configured for any
of the three I/O locations, except Desterm 128.  Matt has made noises about
adding support for $DF00 and $D700 in an future release.  (Matt, comment?)

Cheers,

Kent Sullivan
Microsoft Corporation

The opinions expressed in this article are my own and do not necessarily
reflect those of my employer.