Talk:11000 Series plug-in interface

The part about there being no 11000 horizontal plug-in slots is complicated. I'm not sure about the digital 11000 mainframes (i.e., 11400 and DSA600), but in the 11300, the right plug-in slot is special.

First, a small caveat about 11300 nomenclature: In most places, the slots are referred to as "LEFT", "CENTER", and "RIGHT". In some internal documents, though, the slots are referred to as "LEFT", "RIGHT", and "AUX". One example of the confusion can be seen in the 11301 SDI signal wiring schematic, where names of the wires on the left side of the schematic (i.e., pin names on the SDI chip) don't agree with the names of the wires on the right side of the schematic (i.e., the interface board pin names). This is really confusing since "RIGHT" sometimes refers to the middle slot and sometimes refers to the rightmost slot. The public documentation (and user interface) are consistent: the slots are called "LEFT", "CENTER", and "RIGHT".

The RIGHT plug-in slot in 11300 scopes is funtionally a horizontal slot in the following ways:

• The main signal output (pins 11A/11B) from the plug-in in the right plug-in slot cannot be routed to the vertical deflection plates of the CRT.
• The main signal output (pins 11A/11B) from the plug-in in the right plug-in slot can be routed to the horizontal deflection plates.
• The trigger output signals from the LEFT and CENTER plug-ins are routed to the RIGHT plug-in. This can be seen in the 11301 Interface Board schematic, an excerpt of which is here: Trigger signal feeds from LEFT and CENTER 11301 plug-ins to RIGHT plug-in.

So in some sense, the right plug-in slot of 11300 mainframes is a horizontal slot. But Tektronix did not sell any general-purpose timebase plug-ins for the 11000 Series, so it's not clear what they expected people to do with the rightmost plug-in slot.

As a matter of trivia, if one were to call the 11300's RIGHT slot a "horizontal" slot, then might be the only Tek scope that has a timebase part of the mainframe and also an easily swappable module.