cccph@jessica.cs.ucla.edu (Charles Hobbs) (05/21/91)
I have two 16K Color Computers, a Coco 1, and a Coco 2. Initially, the Coco 1 had Extended Basic, the Coco 2 did not. I also have the Color Disk Controller, and one disk drive. For a while, I was using the disk drive with the Coco 1. But, I wanted to take advantage of the nicer keyboard on the Coco 2. Since the Disk Controller requires Extended Basic to operate, I pulled the Extended Basic ROM from the Coco 1 and put it in the Coco 2. The Extended Basic works fine in the Coco 2. When I plugged the Disk Controller into the Coco 2, with Extended Basic, the system boots up into Disk Extended Basic, but the disk doesn't operate at all. (I've checked the cable, and it's installed properly.) DIR, FREE(0), DSKINI 0....all that happens is the disk will spin for a while....and then ?IO ERROR. Ok, is there something in the Coco 2 that I am forgetting about? Thanks in advance.... ____________________________________________________________________ |Charles P. Hobbs | BBC micro, Aquarius and Spectravideo |cccph@jessica.cad.ucla.edu | users! Please email me! Thanks! |Ham radio: N6YMK | L.A. Blue Line Freq: 471.3375 mHz
ww0n+@andrew.cmu.edu (Walter Lloyd Wimer III) (05/21/91)
Your disk controller is probably one of the older Tandy models which required +12v in addition to +5v. The CoCo 1 supplied +12v but the CoCo 2 and 3 do not. You need to do one of the following: 1.) Get a Multipak Interface (I think all the Tandy models supply +12v, but I'm not entirely sure). Multipaks are rather difficult to find. You might find a used one for sale, or maybe a third-party version (make sure it supplies the +12v). 2.) Get a newer disk controller which does not require +12v. 3.) Hack your drive and controller to get the +12v from the drive power supply. This is what I did in order to run my old controller in my CoCo 3; it worked fine. Make sure you tap off the regulated side of the power supply. You also have to turn on the drive first, then the computer (the WD1793 disk controller chip requires the +12v to come up either before or at the same time as +5v). 4.) Hack your CoCo 2 to supply +12v. 5.) Use some kind of external +12v power supply. This and (4) are pretty similar since you'll probably need many of the same components (transformer, rectifiers, filter capacitors, voltage regulator). Good luck, Walt Wimer