[GreenKeys] Bell 28LA Waterfall (Stacked Page Printer) Info?

[Jim Haynes]

On Sat, 8 Feb 2014, Nick England wrote:
> 
> For that matter was there ever such a document for any M28 set or individual
> piece of M28 teletype equipment? It seems like there were ten thousand

My understanding is that for most of the time to get a complete set like
a Model 28 KSR you had to order the LAC, the LESU, the LK and the LP and
the LMU and the gear set as separate items; and I don't know if you could
get them factory assembled into a set - probably you could.

In the early 1960s they developed some codes starting with VSL that were
for complete sets ready-to-use with a specific set of components.  There
were also some VCL numbers which were components of larger things but
were a composite of several individual pieces.

Now the military had somewhat the opposite problem: they would define a
UGC-mumble that was a specifically configured set, and if you needed
something slightly different it would have to get a different UGC (or
FGC, or GGC or SGC) number.

Of course if a customer ordered enough sets configured alike they would
build them to order as the customer wanted.  No doubt this applied to
the Bell System basic models; and then people in the field could apply
modification kits to provide variations.  In the Bell System case there
is the added complexity of equpment being leased and regulated, so a
particular feature might be tariffed for a certain monthly charge; or
it might be a no-charge alteration.

So no doubt there was a document containing all the VSL and VCL numbers,
but I've never seen it.  There were analysis charts for various set
components that showed various things about them.  Often these were
numbered in with the wiring diagrams, even though they were not wiring
diagrams.

I'm looking at 3143WD with is called an "Operable Combination Wiring
Diagram (it isn't) for Model 28 typing units.  It shows, for example

LP10 has the AEX stunt box.
LP11 also has the AEX stunt box, and it doesn't say what is different.
LP12 can have the AJ, AK, AL, AEY or AFM stunt box.

Then there is LAK/AC for 28/35 ASR keyboards.  This has several pages of
different features coded, and then for each model tells you a list of
those coded features, the wiring diagram, the customer, the 6000 
specification if any, and in some cases a photograph number.
Thus LAK1 is "basic"
LAK2 is for the Navy
LAK3-LAK4 are "basic"
LAK5-LAK6 are cancelled
LAK7 is for Western Union
and on it goes.

I imagine the Bell System had its own set of documents using the
28A 28B, etc. numbers instead of the L codes.

In general this is why Teletype had sales engineers, whose expertise was
in configuring equipment to meet the customer's needs, and initiating
development of new parts and features if there was no existing way to
meet the need.