74LS21 fails with TL866

gmc

Testing a known good 74LS21 fails with  TL866II-Plus App Ver 11.90

yovish

回复 1# gmc


   Please post a screenshot showing the erroneous test.

yovish

I can already see the screenshot, it hasn't displayed for a while,

Yes this logic vector is wrong, because pins 3 and 11 are unused/not connected (NC), so instead of expecting the value "H" (TTL logic level high/logic value "1"), there should be an "X" there as shown. In some time this vector should be corrected. Thank you for the information.

Please have the administrator move the topic to this directory:
http://forums.xgecu.com/forumdisplay.php?fid=17

yovish

回复 1# gmc

   Out of curiosity I checked what the logic vector of the 7421 chip looks like from other companies. I found a couple of companies that also have the wrong vector, but I guess they don't have as much support as XGecu, which will have a revised logic test any day now.