[time-nuts] Spectracom 8182 Netclock/2

Bruce Lane kyrrin at bluefeathertech.com
Sun Oct 16 05:36:45 UTC 2011

	I went through something very similar when I reverse-engineered a module Data I/O used in their programmers for disk storage (the MSM, or Mass Storage Module).

	The best way I've found to do it is make a drawing of the board itself, plus all its IC's and other components. Doesn't have to be anything fancy, just an outline plus little rectangles (suitably labeled, of course) for the components.

	Next, identify your power and ground rails.

	Finally, using a continuity tester (preferably something which beeps when it gets shorted), start with a pin on an IC you know is not the IC's Vcc or ground pin, and check for continuity to every other IC and component. Lather, rinse, repeat.

	As you go, make a "netlist" of which IC pin connected to which component, or power or ground rail. Example:

U1-11 (means the IC labeled U1, pin 11): U2-6, U5-2, 10k pullup to +5

	This means pin 11 on U1, pin 6 on U2, and pin 2 on U5 would all be connected together, and to a 10k pull-up resistor to the +5V rail.

	Once you finish doing the entire board, you can sit down at your computer with your favorite schematic-drawing package and your netlist, and re-draw the circuit. Yes, it's time consuming, and takes lots of patience. It took me over a month to do the MSM, and that was a relatively simple board. However, in the end, you have a very usable schematic and a great idea of how the circuit elements interact. This is never a bad thing.

	Happy tweaking.

*********** REPLY SEPARATOR  ***********

On 15-Oct-11 at 16:53 Bob Betts wrote:

>Hello All:
>I have four Netclock/2 systems (model 8182), from Spectracom, which are
>being modified for a switching broadcast monitor console. I'm in the
>process of reverse engineering the schematic, since service schematics
>seem to be totally unavailable. It's a time-consuming process and quite
>tedious. When chip numbers are erased, it gets to be even more exciting.
>Anyhow, has anyone else ever done any work along this line? Maybe we can
>swap and combine info, or possibly someone might have an actual schematic.
>These were typically purchased for broadcast studios.
>These are obsolete as far as the company is concerned, but they refuse to
>support a customer's investment with just a few sheets of paper (we bought
>4 of them). They won't even supply documentation for "new" products.
>Maybe I'm too old fashioned, but after 48 years of manufacturing
>specialized comms equipment, we'll go way out of our way to support our
>dedicated customers ... old and new. What I do know is that I won't do
>business with them, again.
>Any help will be gratefully appreciated.
>Please let me know any cost involved.
>Thanks in advance,
>(ACE - AmComm)
>* Music * Audio * Radio *
>"It's all good"
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Bruce Lane, Owner & Head Hardware Heavy,
Blue Feather Technologies -- http://www.bluefeathertech.com
kyrrin (at) bluefeathertech do/t c=o=m
"Quid Malmborg in Plano..."

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