VT100 and/or VT105 rescued from scrap
ard at p850ug1.demon.co.uk
Thu Oct 22 09:48:12 CDT 2015
> The way I remember it is that the VT100 comes in several configurations (for example AVO or
> not) and you can field modify it from one to another.
> On the other hand, the VT101 and VT102 are fixed configs (that is, not intended to be field
> upgradable), roughly matching the base and AVO versions of the VT100 in functionality.
That is basically how I remember it too. The VT100 was terminal that could be field-upgraded, the
AVO  added, printer port added, graph board (VT105) added, and so on.
The VT101 is (officially) a fixed-configuration terminal, similar in features to a 'base' VT100
The VT102 is a fixed-configuration terminal similar in featurers to a VT100 with AVO and
printer port (?)
Internally the chassis metalwork and PSU are very different between the VT100 and the VT101/VT102
The logic boards are different too, but from what I remember the circuit ideas are much the same, the
same 2 custom chips are used in the video circuit of all these terminals. Am I remembering correctly,
the VT100 uses an 8080 processor, the VT101 (and VT102 I guess) has an 8085?
 That acronym is a bit strange for me. Over here, AVO (standing for Amps, Volts, Ohms) is
a famous brand of multimeter (analogue and digital) and also other test gear like signal
generators and valve testers. It is one of those trademarks like 'Hoover; that has almost
become generic, people over here will ask for an 'Avo' meaning a multimeter.
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