sergey
Veteran Member
Most newer LSI ICs are CMOS, that includes RTL8019AS Ethernet controller, various VGA controllers, etc. And they will have CMOS level outputs - very close to VCC == 5V for logic "1", that would work just fine with 74HC.Regarding the potential logic level issues, I have an RTL8019 ethernet card running in the ISA expander. Its ASIC must be compliant with the HC series logic. If anyone is having trouble with ethernet cards, I can vouch that the 8019 works in my unit. Ethernet has been really handy to move files back and forth to a windows computer running an FTP service. I'm using mTCP.
The problem will likely happen when TTL or NMOS outputs are connected to 74HC inputs on the Book8088 board. That includes ICs like 74LS245 that are often used to buffer the data bus on ISA cards, including some newer ISA cards.