Vt180, whats the story here?

Quite possibly. You can add the AVO to any VT100 (and it remains a VT100 IIRC, although doubtless the suffix changes). And then add the STP (or a graphics option or...)

Physically it's a daughterboard on the VT100 logic board that contains some extra video RAM, etc. It allows you to have 24 rows of 132 characters, extra text attributes, etc. Unless it's faulty, leave it in place. It can do no harm, and in general it makes the VT100 work like most modern programs expect a VT100 to behave. I believe the STP _is_ the VT180 processor. I am going to guess a bit here. My guess is that the STP connects to a paddleboard that goes into the edge connector on the VT100 logic board. This is a very clever piece of DEC design -- the contacts on this edge connector are designed to touch if there's no PCB inserts. By so doing they connect the VT100 logic to the RS232 connector on the back. By inserting a PCB you can intercept this connection, allowing the VT100 terminal to talk to the STP and also the STP to talk to the host via the RS232 connector. A second guess is that if you remove the PCB from this edge connector, the thing goes back to being a normal VT100. [...] DEC made a thing called a VT105, which is a VT100 with a 'waveform generator' board in it. This was a 'graphics' terminal, but you could only display 2 points in each vertical column (or all points _below_ one of those points). It was thus ideal for drawing graphs or barcharts but not a lot of use for drawing anything else. There were 3rd party graphics cards as well. One that I remember was called a 'retrographics'. They normally emulated a Tektronix 4000 series terminal on the (raster-scan) VT100 display. As to whether linux can drive them, well, both of the above were controlled by control sequences sent over the RS232 port, which obviously linux can do. As to whether gnuplot can do it, well, I would think it could drive a Tekky 4000 (since most things can...), but I doubt if it can do the VT105. No idea where you get either of these boards, either... [...] Block 1: Scroll (0=jump, 1=smooth) Autorepeat (0=off, 1=on) Screen (0=dark background, 1=light background) Cursor (0=underline, 1=block) Block 2: Margin bell (0=off, 1=on) Keyclick (0=off, 1=on) Emulation (0=VT52, 1=ANSI) Auto Xon/Xoff (0=off, 1=on) Block 3: Shifted-3 (0=#, 1=\pounds) Wrap around (0=off, 1=on) New line (0=off, 1=on) Interlace (0=off,1=on) Block 4: Parity (0=odd, 1=even) Parity (0=off, 1=on) Bits/Char (0=7bits, 1=8bits) Power (0=60Hz, 1=50Hz) [...] There is no genlock, the VT100 has to be the sync generator. Composite out is what you expect -- a composite feed to an external monitor, etc. Composite in is strange. You first have to extract the sync from the composite out socket, and lock an external video source to that. You can then feed the output of that video source into the composite in socket, where it will be displayed on the VT100 screen, overlayed with the text from the VT100 itself. But notice the external source is synced to the VT100 and not the reverse. PResumably the Modem7 program is rather more user-friendlt than the one in ROM... Next/Prev screen were not VT100 features, AFAIK, so I guess DEC didn't see any need to make them work with the built-in VT100 emulator. -tony