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

Mark Ormond markormond at mtxsystems.com
Tue Nov 2 07:43:52 EDT 2010

It has a 6551. I just replaced the crystal (I remembered my extra swiftlink clone board had one) and it's currently doing read tests.
Seems to be working fine, but I'll wait for more testing before I declare it working.

Now I just need to mod the udrive leds over to the cd and on leds on the outside of the case. (And maybe dim them some.)

Gotta quit playing and get to work now.


-----Original Message-----
From: coco-bounces at maltedmedia.com [mailto:coco-bounces at maltedmedia.com] On Behalf Of Little John
Sent: Tuesday, November 02, 2010 12:44 AM
To: CoCoList for Color Computer Enthusiasts
Subject: Re: [Coco] Driect Connect Modem pack to Drive pak conversion.

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...

----- 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.
> --
> Coco mailing list
> Coco at maltedmedia.com
> http://five.pairlist.net/mailman/listinfo/coco 

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