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Can JDM program 16F628 ???

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New Member
Hi, All Gurus!

I have build a JDM programmer, and use ic-prog on my win2k machine.

I cannot use it to program 16F628 chips, BUT I have had NO PROBLEM programing 16F84A. I use the default setting on ic-prog.

I suspect there is a difference when programming 16F628 and 16F84A, even they are "pin-compatible".

I also cannot see on JDM's website saying that it supports 16F628.

Now here are my questions:

Has any of you succeeded programmin a 628 using ic-prog + JDM?

If yes, is there any things I need to do (hardware/fortware)?

If no, what are you using to program 16F628? (prefer a DIY way)

Any help will be much appreciated!!! :D



New Member
Problem solved.

Thanks for the reply.

My problem solved. The JDM2 schemtics shows pin10 (RB4) connects to Vdd. I changed it to connect to Vss. Now it programs both 16F84A and 16F628.

This (important) change is documented at the very bottom of the JDM site page, mixed with some other information - which is easy to be skipped if you just want a schematics to build the JDM.

Anyway, connects RB4 to the ground.

Thanks again.


New Member
The RB4 pin must be connected to ground because otherwise the PIC will enter in low voltage programming mode and JDM won't work.
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