[Coco] Driect Connect Modem pack to Drive pak conversion.

[Little John]

Replacing the Crystal may require that the 6551 be replaced with a 6551A, 
which is a good idea anyway since the 6551A is rated at the 2Mhz bus speed. 
Of course if it works without replacing it, then I guess the "if it ain't 
broke don't fix it" applies :)
Or did the DCM Pak have a 6551A? My deluxe RS-232 has the 6551...
JohnT
====

----- Original Message ----- 
From: "Mark Ormond" <markormond at mtxsystems.com>
To: "CoCoList for Color Computer Enthusiasts" <coco at maltedmedia.com>
Sent: Monday, November 01, 2010 11:28 PM
Subject: [Coco] Driect Connect Modem pack to Drive pak conversion.


>I scored a Direct Connect Modem Pak off ebay with a joystick and Orchestra 
>90-cc pak for cheap.
>
> I really don't need a modem, so I decided to try to make it into a drive 
> pak.
>
> To do the basic conversion you will need.
>
> 1 28 Pin socket.
> 1 udrive
> 1 microsd card.
> 1 27128 thru 27512 (your choice) eprom with coconet. If using a larger 
> rom, just repeat the image till the rom is filled.
>
> Cut the rom from the modem pack and install the 28 pin socket.
> Run a jumper wire from pin  2 of ic3 (74ls133) to pin 26 of the rom 
> socket.
> (This enables A13 on the socket, thus giving us 16k eprom capability)
>
> Go ahead and install your eprom and make sure coconet comes up.
>
>
> Now turn over the board and solder a jumper wire between pins 16 and 17 of 
> the 6551 uart (IC2)
>
> Next up, cut out the modem chip located at IC5 (74HC943n) (Yes this chip 
> is a 300 baud modem)
>
> Now from the empty socket The pins you will need are as follows.
>
> Pin 5 RXD
> Pin 6 VCC (+5)
> Pin 11 TXD
> Pin 14 GND
>
> Socket Udrive
>
> 5 4
> 6 5
> 11 3
> 14 2
>
> Please double check and triple check your connections here.
>
>>From the Udrive check for continuity to the following.
>
> Udrive card edge pins
>
> 2 33
> 5 9
>
>
> Udrive 6551 Uart (IC2)
>
> 3 10
> 4 12
>
> Now throw in your microsd card that you have written the distribution 
> image to using Cocopak and turn on the coco.
>
> Right now it's running at 115200, I'll swap the crystal when I have a 
> chance.
> I don't have reset for the udrive hooked up at the moment either.
> I've also rigged up the connect switch as a halt switch and
> I'm going to use the mode switch for hi low eprom bank select (a14).
> The card just fits thru the modem phone jack hole, and the udrive is held 
> in place with double sided foam tape. (From Radio Shack of course)
>
>
> Thank you for all your hard work Roger.
>
>
> Please support Roger and his work. Without it, this hack wouldn't have 
> been possible.
>
>
>
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