"Zane H. Healy" <healyzh at aracnet.com> wrote: I can fill in a few details. More later, if there is interest... The VS11 and VSV11 are graphic subsystems for the Unibus and Qbus (the VS11 is a VSV11 and a bus adapter, ISTR). I have never played with one, but have some basic documentation that mentions it. It is definitely supported under RSX. The follow up product was/is called VSV21. This thing can do 640x480 with 16 colors (out of a palette of 4096). It has a very intelligent graphic processor, which can do all kind of operations in hardware. The VSV21 was atleast used by mass spectrometers, which is where I got mine from. A few are probably still in use around the world. I do have the RSX software for this thing (unfortunately not the latest version, though), and the manuals (but only for the software, not much hardware info, unfortunately). So I can't tell how the low level interface works between the graphics system and the PDP-11. What I do know is that the graphic system has it's own memory, and also use DMA. So graphic objects can reside either on the PDP-11, or on the praphic system, and be drawn by the graphic processor from either source. They can also be copied back and forth. The VSV21 can also act in a VSV11 compatible mode, by loading other microcode (that's where all my VSV11 knowledge comes from). As I remember the differences are that the VSV11 have lower resolution, less colors, and a simpler hardware accelerator for graphics. From a user application point of view, they are interchangeable. The VSV21, loaded with VSV11-compatible microcode, can be used by programs written for the VSV11, since all the operations goes through a device driver and (normally) a library as well. I've been meaning to write some fun software to play with the VSV21, but haven't had time yet. If someone needs some information, or wants to talk more, just ask ahead. Johnny