yes why can't TTL logic have negative logic output?
Added after 1 hours 59 minutes:
Since you don't have a -5 supply, the negative polarity must mean that the output is inverted
1.) Whats the difference between TTL inverted VS TTL polarity?
If you are actually seeing a negative output on a 74HCxx chip, then either you're using +5 as the measuring reference, or your o'scope is running with the INVERT switch active on that channel.
Yes im actually seeing a negative output on the 74HCxx chip , the circuit does have a +5 supply and a -5 supply
But the way the 74HCxx chip is reversing the polarity doesn't use the -5 supply at all, it just uses the ground and +5 volts on the inputs to reverse the polarity on the output
I'm guessing since the circuit uses a bipolar power supply +5 ,ground, -5
Then you can reverse the polarity on any digital logic chips output by changing the ground and +5 volts on the inputs to any logic chip ? so the output flips the polarity?