You might be able to do it without terminating each line provided you use
or provide a ground plane on both sided of the cable.

Some of the ribbon cable has a copper mesh ground plane already installed,
it's easy to spot because it's thicker and heavier than the standard ribbon
cable.

I used to strip the shield out and use it for shielding rf circuits because
the copper was easy to bend, shape and solder.

While your clock only runs at 4 Mhz, you need approximately 10 that
frequency response if you are hoping to maintain reasonably square waves.

Don't over look the etch on the pcb as a source of ringing....if possible,
put a ground plane under the board also.

We had a 10 Mhz signal to a laser transmitter that was ringing (LS TTL
driver). The output and inputs were high impedance and we had to use rg-174
with bus driver chips and 100 ohm termination resistors to clean it up and
get data to pass.

Try it, but be on the lookout for inconsistency and intermittent operation.
Also, be on the lookout for rf interference as well, those high impedance
lines with unshielded conductors make nearly perfect antennas.

Good luck.

Art





At 01:23 PM 6/11/03 -0400, you wrote:
>I have a project board set up for a 28 pin OTP device.
>I would like to adapt a 40 pin ZIF to the devices that I can experiment with
>a 16F874.
>Mechanically I can adapt an IDE cable from a PC to another circuit board
>with the ZIF pretty easy.
>
>The question:
>Can I get away with using about 8 inches of ribbon cable between these
>boards?
>It is only running at 4mhz.
>
>John Ferrell
>6241 Phillippi Rd
>Julian NC 27283
>Phone: (336)685-9606
>johnferrell@earthlink.net
>Dixie Competition Products
>NSRCA 479 AMA 4190  W8CCW
>"My Competition is Not My Enemy"
>
>--
>http://www.piclist.com hint: PICList Posts must start with ONE topic:
>[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

--
http://www.piclist.com hint: PICList Posts must start with ONE topic:
[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads