27 Dec
2002
27 Dec
'02
1:25 a.m.
Fred Flintstone wrote:
I guess I should have been more specific :-)
I have what appears to be an OEM LA36. The label on the front says
'Data Terminal Mart'. On the back, there is a label from Digital
which gives the model number as LA36DP. The processor board inside is
made by Datasouth Computer Corporation (P/N 512000-2). There is an 8
DIPswitch located on the board. I do not have any documentation for
this particular model and thus, I do not know what the settings should
be on the switches. I do have user docs for an older LA36, but it
does not cover my particular model.
Oooh, a Datasouth board. I'm afraid that the schematics/documentation of an
LA36 are probably not going to be very useful to you. You probably also
have
a heat sink bolted to the the printhead. Original LA36's do not have a
heatsink.
What you have is an LA36 plus an aftermarket modification to speed it up.
I think Datasouth started business with this modification, then went on to
build entire printers themselves.
The original LA36 would max out at 30 characters/second printing (with
a good headwind). The Datasouth board (+extra bits) replaced the original
logic boards in the back of the printer, and sped up the printing
to around 120 characters/second(?) and bi-directional printing, but needed
a heatsink on the poor printhead so that it wouldn't melt down. It gave the
LA36 speed closer to that of the LA120.
You need documentation on the Datasouth board. Datasouth, the company,
is still apparently in existance (http://www.datasouth.com), and you might
try contacting them.
I am looking for information on the LA36, specifically the 8 dip
switches.
What I am trying to accomplish is to get the terminal console working
on my PDP-11/10 (really it is a PDP-11/05) prior to getting my
PDP-11/20 running.
When I hook everything up, the SCL on the PDP-11/10 has the expected
voltages. When I connect it up to the LA36, the voltages are driven
to near 0v. I am not sure I have things hooked up correctly, or if
there is a problem with the SCL. I used the docs I had for the older
LA36 to connect my LA36DP. The connections I made were from T+ on the
PDP-11 to R+ on the LA36 and T- on the PDP-11 to R- on the LA36. When
the LA36 is not connected, there is no voltage on the Transmit/Receive
which I am presuming means the LA36 is in passive mode. Voltages are
present on the Transmit/Receive on the PDP-11 side, and I presume the
SCL is in active mode.
Unfortunately, I am not sure if this is correct (I am from the RS232
generation, the 20mA is slightly confusing).
Any ideas?