Apple Disk II, was Re: TRS-80 Model I

Dave McGuire mcguire at
Sun Feb 4 17:56:07 CST 2007

On Feb 4, 2007, at 4:05 PM, Tom Peters wrote:
> Before even letting the customer leave the premises, I'd quickly  
> take out the four screws that held on the cover and show them the  
> blackened spot on the inside of the cover, then show them the  
> 74LS125 in the middle of the board, which invariably had been  
> cracked or cratered.
> The documentation clearly said, connect the ribbon cable to the  
> controller with the cable exiting AWAY from the board. But there  
> were any number of folks that went the long way around, and put a  
> great deal of effort into bending the cable sharply where it exited  
> the ID connection, so that they could plug it into the controller  
> card backwards.
> This usually resulted in a spectacular failure of the '125.

   Did that failure take out anything else, or did replacing only the  
74LS125 solve the problem?


Dave McGuire
Port Charlotte, FL

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