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- These are some comments on the interface provided by GNU libplot to
- Tektronix emulators.
- The Tektronix device driver included in libplot produces output for several
- types of Tektronix-compatible display. This includes the Tektronix
- emulators built into `xterm' (the X Window System terminal emulator) and
- the MS-DOS version of `kermit'. They are recognized by the environment
- variable TERM equalling "xterm" (or "xterms" or "kterm"), and "kermit" (or
- "ansi.sys, "ansi.sysk", "ansisys", or "ansisysk"), respectively.
- Some historical comments on the Tektronix 4010/4014 follow.
- A Tektronix 4010 had what was effectively a 1024x780 display, as did the
- first Tektronix 4014 models. Effective coordinate space was
- [0..1023]x[0..779]. Extended resolution, available for Tektronix 4014's
- equipped with the Enhanced Graphics Module [EGM], yielded
- [0..4095]x[0..3119] as coordinate space. Actually the range of the two
- position registers was always [0..4095], even before the EGM was
- introduced. (On displays without EGM, the low two bits in each coordinate
- were dropped.) So the upgrade path to the 4014-with-EGM was smooth.
- In pre-EGM days a Tekpoint increment (display measurement unit) equalled
- four increments of the x or y position register. `Home cursor position'
- was (0,767) in terms of Tekpoints, since the character matrix was 7x9.
- After the introduction of the EGM, a Tekpoint increment equalled one
- increment of the x or y position register, not four. Home position became
- (0,3071).
- There were approximately 70 Tekpoints/inch in pre-EGM days, 280/inch with
- EGM. In other words, the resolution was better than that of high-end
- workstation displays today. Who says raster graphics is an improvement
- over vector graphics?
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