Tristan Mumford wrote:
Jon wrote:On Mar 2, 8:50 pm, "David Wilson" <mcs6...@gmail.com> wrote:But I just had a look at the circuit diagram for theDisk ][ controller card (in The DOS Manual) and it uses the 74LS05 (the low voltage version of the 74LS06). Jaycar do sell these: CAT. NO. ZS5005 RRP $0.60Hmm, even more interesting is, Jaycar also has 7406s (CAT. NO. ZS5806). Is the clone Disk ][ controller a 1:1 clone of the apple card? It might be better then to use the 74LS05?No, it's rather different. it only has one big rom, which is 2k in size and paged. To be honest I like it better than the real thing.
Tristan, if you want to be *sure* that the '05 is an appropriate IC, check the output pins on the empty socket that the '06 was in while the controller is powered and see if any of them is pulled up to a voltage higher than +5v. -michael NadaNet networking for Apple II computers! Home page: http://members.aol.com/MJMahon/ "The wastebasket is our most important design tool--and it's seriously underused."