I'm trying to substitute the obsolete NAND chip in this circuit (part of an audio synthesizer) with a standard CMOS one (for example CD4011). The original NAND chip is a DTL chip by Motorola, MC846.
datasheet: http://pdf1.alldatasheet.com/datasheet-pdf/view/130532/MOTOROLA/MC846.html
The pinout is different but I don't care about that, I'm only worried about electrical differences.
I don't think I can just put the CD4011 in place of the MC846, I'm not sure about that but I may need pull-up resistors, and then I read on the MC846 datasheet that it contains "wired OR" and I don't know what that means.
Also, what I'd like is to remove the 5V supply and only use +/-15V.
The LM301 comparators are indeed powered by bipolar 15V, but as you can see their outputs are forced to 5V since the MC846 can only be powered up to 5V (is this the purpose of the 2 diodes on the pin 8?)
The final output of the NANDs network is going to a normally closed electronic switch
Can anyone help me figure out how to do those mods? thank you
UPDATE
what do you think of these mods? I've added diodes on the output that goes together, and then pullup resistors. Would this work now with CMOS NANDs?
If yes, now I need to understand how to remove the 5V supply (not needed anymore since the CMOS chip can withstand 15V.
