VT105 – the graphical terminal for MINC

The most important part of a MINC system for sure – the vt105 graphical terminal. Graphical as in wave form graphics – another of those bits of IT history that existed only for a brief period in time, when memory cost was so high that the bitmap based graphics we now take for granted would have been prohibitively expensive.

With its limited storage, vt105 is surprisingly capable, and the combination of graph lines, markers, and shade lines makes for graphs that can be compelling even by today’s standards. And current systems with their abstraction layers between program and hardware might even struggle to show shaded strip charts like the vt105 can.

Information sources
Information about the vt105 is mostly from the EK-VT105-TM-001 manual (as found on Bitsavers) and confirmed by running the ZVTN maindec and the examples from MINC-11 Book 4: MINC Graphic Programming. Also, the base vt100 behaviour of the terminal has been confirmed by vttest.

Unknown/Missing information
None currently identified.

Implementation status
The implementation has been verified to all examples in the MINC-11 Book 4: MINC Graphic Programming.

The current implementation only enables the square graph form as described in EK-VT105-TM-001. Since in the software that is available at this point only the square form is used, it doesn’t seem urgent to also implement the rectangular format.

Some of the base-vt100 features have not been implemented, but these are not directly relevant for use with MINC – for instance, 132 column mode, soft scrolling etc.