Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!rutgers!cbmvax!fred
From: fred@cbmvax.UUCP (Fred Bowen)
Newsgroups: comp.sys.cbm
Subject: Re: TWO CARTRIDGES AT ONCE
Message-ID: <7107@cbmvax.UUCP>
Date: 21 Jun 89 12:25:28 GMT
References: <89061907384920@masnet.uucp> <3028@csd4.milw.wisc.edu>
Reply-To: fred@cbmvax.UUCP (Fred Bowen)
Organization: Commodore Technology, West Chester, PA
Lines: 36

In article <3028@csd4.milw.wisc.edu> (Joe Greco) writes:
>In comp.sys.cbm article <89061907384920@masnet.uucp>, (ALEX BURGER) wrote:
>]
>]Has anyone firgured out how to use the 1750 REU, and lets say FASTLOAD! 
>]at the same time?
>]
>]If they can hook up two REUs at the same time, then I imagine that this 
>]is possible.
>
>WHO'S figured out how to hook up two REU's at the same time?  SOMEONE
>PLEASE TELL ME!  :-)

Sorry, I thought I did tell you :-)  While your special decoding looks fine
to me (what do I know- I'm not a hardware type), my simple modification of
the chip select (from IO2 to IO1) works.  I don't believe there is anything
particularly unique about the IO1/IO2 timing.  If I had the time, I would
duplicate your decoder hardware and try it.  The only other difference
between your setup and mine is the computer- I use a C128, you use a C64.
I trust you have modified the 1700/1750 C128-compatible REUs to work properly
on your C64.

If your software is so flexible that it works wherever the REU is located,
I trust your software for the MSD cartridge is too- move it to your newly
decoded region :-)  Perhaps the additional TTL delay you introduced is the
culprit.

The scheme I used has worked for others.  One word of warning- the power
supply is a real issue, so folks who have not beefed up their power supply
as Joe has should not attempt this, particularly on a C64.
--
-- 
Fred Bowen			uucp:	{uunet|rutgers|pyramid}!cbmvax!fred
				arpa:	cbmvax!fred@uunet.uu.net
				tele:	215 431-9100

Commodore Electronics, Ltd.,  1200 Wilson Drive,  West Chester,  PA,  19380