Service Manual/Schematics for an IBM 7861-015 modem?
mcguire at neurotica.com
Sun Feb 11 20:01:25 CST 2007
On Feb 11, 2007, at 8:40 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. :-(
> 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.
Port Charlotte, FL
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