There are often multiple virtual TTYs. These are generally found at Ctrl+Alt+F1-F6. When you startx, it generally lives at Ctrl+Alt+F7. You can open up to 6 instances of X on the TTYs at F7-F12 using commands like this:
This starts another instance of X on Ctrl+Alt+F8.
This starts X on Ctrl+Alt+F9 etc.
In Slackware, TTYs on F2-F5 are disabled; F1 is the boot info you see before KDM/XDM kicks in (if you boot to runlevel 4); F6 is a spare one for times like just1newbie's where you need access to a console because your X is borked.
That's my understanding anyway