problem with my EPIC

[gebillpap]

I have the same problem also.
I will try to define it better.
I use PICBASICPRO(2.46) to compile a program that programs (EPIC2.46beta) and runs OK on a PIC 16F84 or16F84A .

The same sourcecode with proper mods for 16F628 or 16F628A gives "CODE PROGRAMMING ERROR " using Epic but does program and run as expected when I use MPLAB IDE +PICSTART (I was only able to test 16F628 because the 16F628A needs an upgrade to the PICSTART and I dont yet have it) .

So the source code is OK chip is OK and the problem lies with Epic programmer/software which on the other hand works fine with other procesors.

My intention is to use 16F628A and not 16F628 since it is the newest chip.

The Epic 's programmers options have been taken care off.
The power DC supply is OK and I even tried with fresh batteries .
Up today I did search MELABS and found the mods needed on the ZIF base but nothing!!!
I also tested the PGM (portb.4) pin tied LOW during programming which is suggested as remedy from MELABS but nothing)!!!!!!
I searched this Forum but found nothing to solve the problem so i gather it must be only me having problems and perhaps you.

An info bit which I think is suggested somewhere on the net is that maybe
we should change the 7404 chip on the Epic with a faster one?????

I hope someone might help.

[ardhuru]

Try changing the 2 pull ups on the Clock and Data lines from the original 10K to 2.2 K. It worked for me.

Regards,

Anand Dhuru

[gebillpap]

Dear Anand Dhuru
I did what you suggested and it worked .
Thank you for your suggestion.
I believe MicroEnginnering should quote on this as it can be a problem with many others.
Note that I did purchase the Epic programmer built and tested .
Thank you again
BILL

[bitbanger]

Try changing the 2 pull ups on the Clock and Data lines from the original 10K to 2.2 K. It worked for me.
Regards,
Anand Dhuru

Anand,
There are three 10K resistors on my EPIC Plus, and can't find a skematic diagram for it. The help guide lists them as R5, R8 and R10. Which ones are the pullups you mentioned?

I am fighting a weird problem all day trying to program the 16F88 with mine. It programs ok about 1 out 15 trys, and that one only after a full erase.

[ardhuru]

Hi,

In my schematic they are denoted R3 and R4. Anyway, if you have the original EPIC PCB, these two are the ones directly below Q1.

Alternately, you could trace them to pin nos. 12 and 13 on the 18 pin programming socket.

Regards,

Anand

[bitbanger]

Thanks,
My EPIC Plus currently has 1K resistors in for R3 and R4. By any chance did you mean to change the original 1K resistors to 2.2K? I am guessing the idea is to have "stronger" pull-ups right? I guess I'll stick with what I have. Maybe that is what the "plus" part was all about.

[ardhuru]

Hello,

No, if you already have 1 K pullups. dont bother changing them to 2.2K. That is unlikely to help. In this case, I suspect the problem is elsewhere.

Regards,

Anand

[buddhafragt]

you can try to change the 7404 chip.
sometimes he is destroyed because of over voltage at the LPT port.