Right now only two people are allowed to see this section.
What I could do is make it invisible to EVERYONE, including you and Glenn. Then anyone who knows the URL would be able to see it. Would you like that?
In the end it would be more economical to use a CPLD. A more "proper" controller could be made AND some CPLDs will run on 3.3v yet still have 5v tollerant I/O (most chips don't allow inputs above +.3v VCC or so).
Since we're dealing with LS and HC TTL 3.3v logic will work just fine.
The Altair can run with the clock stopped. If you were to look at the memory chips, the read line is held low as long as the computer is stopped. If you "view" memory location 0xA5FB, then the address lines have 0xA5FB and the read line STAYS low. Same thing with any front panel setup.
There are some TTL dram controllers for the Altair, but a 3.3v CPLD with 5v logic kills two birds with one stone, and cheaply.
|