From: Asbjørn Djupdal (Asbjorn.Djupdal_at_idi.ntnu.no)
Date: 2002-08-22 11:19:42
> > But I can't see how to get rid of the 7406 chip. > > That's pretty simple. You can use the AVR portbits like they were open > collector outputs: set the respective output bits (PORTD.0 and PORTD.1) > to '0's, and activate them using the data direction register when it's > neccessary (DDRD.0 and DDRD.1). With DDRD.0 =1, the pin is output (= a > strong 0 level), with DDRD.0 = 0 the pin is input ( = the pin is left > floating) and you can read its value from PIND.0 . That's probably all > about it. Thats clever. I didn't think about it. I just looked at the 1541 schematics where they use a 7406 :) > BTW, if it were smaller, it could call for a CompactFlash as media, > rather than an old IDE HDD. If something at all, I especially like the > noiseless operation of these old computers. A good point. Asbjørn Message was sent through the cbm-hackers mailing list
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