[Coco] Including an SSC

[Bill Pierce]

Tony,
No devices whether on a y-cable or in the MPI can opperate on the same buss addresses. The MPI does not block the busses or it would be useless. You would not be able to use a floppy controller, hd controller and rs232 pak at the same time if that were true.
The whole point is that VERY few Coco program/extension paks with I/O are mapped to the same buss addresses. This is why I can have my FD-502, B&B HD controller, Orch90, and MIDI pak all online at once. It would work on a Y cable as well, as my Orch90 has the pin taped so the rom won't try to start.
Care has been taken through the years to try and NOT clash buss addresses. I only know of a few carts that cause problems in this area and I don't own any of them.
The only real problems with a y-cable if no buffers for protection, weak power supply from the cartport to supply multiple devices and roms. The MPI solved most of this (somewhat) and only started the rom on the selected cart, buffered the busses, and provided better power.
BTW... there's a document floating around that has "most" known bus addresses for most of the Coco carts.... somewhere. I have a copy, but I'm not sure if it's up to date.


Bill Pierce
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-----Original Message-----
From: Tony Cappellini <cappy2112 at gmail.com>
To: CoCoList for Color Computer Enthusiasts <coco at maltedmedia.com>
Cc: etrocanada76 <etrocanada76 at gmail.com>
Sent: Tue, Oct 14, 2014 7:28 pm
Subject: Re: [Coco] Including an SSC




Message: 7 
Date: Tue, 14 Oct 2014 15:12:46 -0400 
From: "Luis Antoniosi (CoCoDemus)" <retrocanada76 at gmail.com> 
To: CoCoList for Color Computer Enthusiasts <coco at maltedmedia.com> 
Subject: Re: [Coco] Including an SSC 
Message-ID: 
        <CAFgJrh_e7TiL=-NATE32r8e-2gp1VBuENrpTShcZEwGSe_v9HA at mail.gmail.com> 
Content-Type: text/plain; charset=UTF-8 
 
>>it only works with carts with no ROM. like SSC, cocomax interface, 
>>wordpaks, etc. You can only have one ROM. 
 
>>The glenside IDE has no ROM so it could be attached with the FDC. Also it 
>>comes with 2 slots on it. 
 
Hi Luis, 
 
I don't see what ROMs have to do with this issue. 
Multiple devices on the same bus cannot use the bus at the same time 
unless they have appropriate decoding & buffering (This is why a multipack 
interface exists). 
Even if there is no software accessing all devices on the bus at the same 
time, 
one device may be trying to drive a signal low, while another device is 
trying to 
drive it high. 
Would you please explain your statement about ROMS? 
 
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