dec 5000 questions

For lord isildur maybe This is a hardware question: Whats the difference between a decstation 5000 and a decsystem 5000? The latter apparently has no graphics capability. On some of my decstation 5000/200 and /240, I have the add on turbo-graphics board -D and -F . these output to the screen with the 3-pin to 3-bnc cable like in the vlc4000. There is also a 3-pin to single bnc cable apparently for grayscale biz. But the cable that connects mouse and kbd via a db15 connector to my decstation also terminates with a single bnc connector. Is this another grayscale output (or b/w only) of the decstation? So why no signal there? Do I have to pull the graphics board to get console output via that db15 plug like in the Vaxstation 3100, where a spx graphics board will exclude the b/w output from the db15 plug? So you cant have it both ways, composite graphics and b/w terminal style simultaneously? Only either or? Thanks for help! Next Q will be howto start in single user mode in order to get new root pwd! fred