[GreenKeys] "Mystery" M28D

[Jim Haynes]

On Sat, 31 May 2008, Duncan M. Brown wrote:

> As far as strange labeling goes, the Museum has what I would call a "Model
> 28 Perforator". Standard M28 keyboard and motor; all it does is punch tape
> (has a neat vacuum cleaner run by the motor to suck up the chad into the
> chad bin).  The label on the chassis identifies it as a "LKPE 500BSF".  But
> the label on the outside of the cover says "Teletype Corporation  Model
> 34/35"
>
Various machines made by Teletype have those letter-number codes on them.
Everything starting with L is Model 28/29/34/35.  So a typing unit is LP-
something, and the 8-level ones are LP-8xx.  Maybe later on they decided
that 5-level stuff should have a leading 5 in the number; that was after
my time.  The letters after the first are kinda mnemonic, but you can't
always predict them.
LP is a printer
LK is a keyboard
LAC is an apparatus cabinet
LAAC is an apparatus cabinet for the ASR set
LESU is an electrical service unit
LPW is a paper winder
LPR is a typing reperforator
LAK is a keyboard for the ASR set
LKPE is apparently a keyboard with a perforator
LXD, LAXD, LBXD, LCXD... are transmitter-distributors
LB is a base
LXB is a base for a transmitter-distributor (as are LAXB, LBXB, ...)
LARP is the multi-magnet parallel input reperforator, non-typing
and they go on and on.

Equipment made for the Bell System usually used the numbered models
so that's why the 28D typing unit.  (which is equivalent to LP-something)

The appearance of a 28D typing unit in the special machine you have is
surprising, suggests some previous owner may have substituted a Bell 
System typing unit for the original one.