MC862P MDTL TTL chip?

[atod]

Hi,

I'm trying to figure out voltage levels (to correctly create a connector) on a early mechanical keyboard. I found the keyboard uses 5V, however there is another lead being used that looks like it supplies something different on a MC862P IC. I looked at the IC's datasheet and it indicates 5V max, 8V continuous and 12V peak (<1 sec). What voltage level should Vdc be? Regulated 5 or unregulated 8? I'm assuming regulated 5.

Anyone know?

Thanks

http://pdf1.alldatasheet.com/datasheet-pdf/view/130564/MOTOROLA/MC862.html

 

[Chuck(G)]

Most DTL ICs can be interfaced directly to TTL. However, a look at my big brown Moto databook from 1969 says that for the "P" plastic DIP version of the MC862, supply voltage typical is 5.0V +/- 10%. For outputs V(IH) is a minimum of 2.5V; V(IL) is 0.40V max.

There are some applications where a TTL IC is a direct plug-in replacement for a DTL one also. For example, the 7410 is a plug-in replacement in many applications for the MC862.

One difference between TTL and DTL is the relative change in supply current with logic state. DTL doesn't change much and so doesn't require much more than a 0.01 µF decoupling capacitor, where the rule for TTL is 0.1 µF.