11 Feb
2007
11 Feb
'07
7:18 p.m.
Had a good day at the Mansfield Hamfest today. I now have some LCD
monitors that I need to scope out power for (+5 @ 2A, +12 @ 1A), a
nixie-tube panel DVM, and a couple of IBM modem frontpanels.
From googling the IBM model number (7861-015), they
appear to be from
a 9600bps 4-wire leased-line modem. I picked them up because
they
have a 20-key keypad with double-shot hex letters (0-9, A-F) that look
really handy for attaching to an 1802 or similar, and a 1x16 char
"british flag" VFD. What I'd really like is to get my hands on a
schematic to skip the step of reverse-engineering the VFD drivers.
Does anyone on the list have any docs on IBM modems at that level of detail?
Thanks for any pointers,
-ethan
11 Feb
11 Feb
7:43 p.m.
On Feb 11, 2007, at 2:18 PM, Ethan Dicks wrote:
Had a good day at the Mansfield Hamfest today. I now
have some LCD
monitors that I need to scope out power for (+5 @ 2A, +12 @ 1A), a
nixie-tube panel DVM, and a couple of IBM modem frontpanels.
Oh now that's a damn good idea. Those modems are all over the
place. I think I will have to grab a couple of those myself! :)
-Dave
--
Dave McGuire
Port Charlotte, FL
From googling the IBM model number (7861-015),
they appear to be from
a 9600bps 4-wire leased-line modem. I picked them up
because they
have a 20-key keypad with double-shot hex letters (0-9, A-F) that look
really handy for attaching to an 1802 or similar, and a 1x16 char
"british flag" VFD. What I'd really like is to get my hands on a
schematic to skip the step of reverse-engineering the VFD drivers.
12 Feb
12 Feb
1:40 a.m.
On 2/11/07, Dave McGuire <mcguire at neurotica.com> wrote:
On Feb 11, 2007, at 2:18 PM, Ethan Dicks wrote:
> Had a good day at the Mansfield Hamfest today. I now have some LCD
> monitors that I need to scope out power for (+5 @ 2A, +12 @ 1A), a
> nixie-tube panel DVM, and a couple of IBM modem frontpanels.
Oh now that's a damn good idea. Those modems
are all over the
place. I think I will have to grab a couple of those myself! :)
Well... for $1 each for 3, if I throw everything away but the keypad,
I still did OK.
With no technical info within a few google searches, I started
dismantling one. It seems that under the keypad is some
mask-programmed 40-pin DIP Texas Instruments microcontroller. :-( I
may just remove the VFD and figure out how to multiplex and drive it
the hard way from some modern microcontroller. 1x16 is handy for
plenty of things.
If anyone does ever turn up anything detailed on these, I would still
appreciate hearing about it.
Thanks,
-ethan
2:01 a.m.
On Feb 11, 2007, at 8:40 PM, Ethan Dicks wrote:
Bummer. :-(
> Had a
good day at the Mansfield Hamfest today. I now have some LCD
> monitors that I need to scope out power for (+5 @ 2A, +12 @ 1A), a
> nixie-tube panel DVM, and a couple of IBM modem frontpanels.
Oh now that's a damn good idea. Those
modems are all over the
place. I think I will have to grab a couple of those myself! :)
Well... for $1 each for 3, if I throw everything away but the keypad,
I still did OK.
With no technical info within a few google searches, I started
dismantling one. It seems that under the keypad is some
mask-programmed 40-pin DIP Texas Instruments microcontroller. :-( I
may just remove the VFD and figure out how to multiplex and drive it
the hard way from some modern microcontroller. 1x16 is handy for
plenty of things.
True, and those displays are gorgeous.
Take a look at Maxim's MAX6921 and MAX6851 chips. Together, they
can easily drive that display with an I2C interface.
The only other thing you'll need is an HV supply for the VFD,
which can easily be done with something like an MC34063. (contact me
for info on that if needed, as I just built one to drive nixie
tubes...the same circuit will easily adjust down to VFD voltage ranges)
It's a lot of work, but again, those displays are really nice. If
I had a handful of those I'd spin a PCB containing the above
circuitry just to be able to use them.
-Dave
--
Dave McGuire
Port Charlotte, FL
11 Feb
11 Feb
10:18 p.m.
Ethan Dicks wrote:
Had a good day at the Mansfield Hamfest today. I now
have some LCD
monitors that I need to scope out power for (+5 @ 2A, +12 @ 1A), a
nixie-tube panel DVM, and a couple of IBM modem frontpanels.
^^^^^^^^^^^^^^^^^^^^
If that is a Weston 1294-series DVM (4.5 digits, TTL, fits standard 4"*1.75"
industrial instr. panel), I can supply the schematic.
Neat find, as LEDs quickly took over the market for such panel meters, the
NIXIE tube ones are not common.
12 Feb
12 Feb
4:06 p.m.
On 2/11/07, Brent Hilpert <hilpert at cs.ubc.ca> wrote:
Ethan Dicks wrote:
Had a good day at the Mansfield Hamfest today. I
now have [a]...
nixie-tube panel DVM...
^^^^^^^^^^^^^^^^^^^^ If that is a Weston 1294-series DVM (4.5 digits, TTL,
fits standard 4"*1.75"
industrial instr. panel), I can supply the schematic.
It _is_ 4.5 digits (with individual + and - masked neon bulbs) and
does fit a standard panel opening, but it's an MDPM-3 by Instrument
Displays, Inc., of Haverhill, Massachusetts.
Neat find, as LEDs quickly took over the market for
such panel meters, the
NIXIE tube ones are not common.
They sure did... one day it was analog meters, nearly the next day, it
was LEDs. The window for Nixie tubes was rather small.
I couldn't believe I saw this one on the table for $3.
-ethan
6529
days inactive
6530
days old
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ethan.dicks＠gmail.com -
hilpert＠cs.ubc.ca -
mcguire＠neurotica.com