Getting hard drive activity LED from IDE card with no pin header \ VOGONS

Getting hard drive activity LED from IDE card with no pin header

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First post, by Grande 3:16

Posted on 2025-09-07, 04:22

Grande 3:16 Offline

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Hello all, this is my first time post.

I have slowly been "upgrading" my NEC Powermate 1 APC IV 286, I've replaced the original MFM card with an IDE card and the hard drive from a 20MB MFM drive to a 270MB IDE drive (plenty for '80s/early '90s DOS games, Windows 3.0 etc). I've replaced the BIOS to a newer one that accepts custom drive specs (as "turbo" mode is keypress I now can't get it out of 8mhz but that's another problem to solve) and everything is going well.

However, the IDE controller card (Miniscribe) doesn't have a hard drive pin header for the front activity LED. I'm finding conflicting information on how to connect a header/wires to the card. Can someone please help me on how to connect it. I get by with soldering/electronics but I'm still a bit of a novice.

Thank you in advance.

Reply 1 of 5, by mdog69

Posted on 2025-09-07, 06:52

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JP2 might be a candidate for a header, especially if one pin goes to the resistor near the IDE connector, and if the other end of that resistor goes to pin 39 on the IDE.

Reply 2 of 5, by Grande 3:16

Posted on 2025-09-07, 11:14

Grande 3:16 Offline

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Thanks for the tip. I did the beep test with a multimeter, the bottom pad on JP2 goes to pin 39 and the top one goes to pin 27.

Reply 3 of 5, by Grande 3:16

Posted on 2025-09-07, 12:36

Grande 3:16 Offline

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Well, it WAS going to pin 39. And then it wasn't. And then it was going to pin 39, 40, and 38. Now it's not going to 39 again. 😒

Reply 4 of 5, by TheMobRules

Posted on 2025-09-07, 18:36

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Another option is to connect the activity LED directly to your hard drive. Some of them have a 2-pin connector on the front of the PCB for this purpose, others have an LED that you can remove and replace with a pin header connector.

Reply 5 of 5, by DaveDDS

Posted on 2025-09-07, 19:07

DaveDDS Offline

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Another option I've sometimes done in the past - connect to the select for the drive - see IDE pinout for details.
(If only one drive - easy to connect via second cable - otherwise you can add a third connector or tack solder wires to
the board)

For a longer cable/larger LED i'd probably build a little driver (as simple as a single transistor) - if you want to condition
on read/write, step etc... you can build a slightly more complex circuit to combine as wanted.

Dave ::: https://dunfield.themindfactory.com ::: "Daves Old Computers"->Personal

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