About using a pic16c74 old hex file to this pic16f74 new uP

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------Question for DM164136 Please Put your question below------

love to download a hex file to this . Have the hex file already compiled using a pic16c74a .. xtal is 4mhz and no security. PLace this hex file into this using a pic16f74 under the same parameters

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is that possible

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Like to use the old assembler is that possible. IDE 6.1 works perfect no error and its easy

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INHX 32 OR INHX 8 CAN USE EITHER

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Welcome to the TechForum evan1! I don’t really see a problem on a surface level as they do come from similar series. I would definitely find a datasheet for both full part numbers and compare the commands though. It all depends about the command set found for both parts. Usually, the compiler is generally the same, however, a certain hex code may be tied to a specific processor and that particular line may not play nicely with the different processor in the other part. Addresses might change too, which may also bring up some issues in migration. The biggest unknown is the header file which establishes which processor is being utilized. The PIC16F74 may reject the entire hex file based on that or it may behave erratically. There are a lot of variables when it comes to processors and hex files.

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Its just one location in memory change .. Can go to a Hex editor and change that one location2007 (h) To support the change for the picl16lc74. LIke xtal crystal and brown out protection and watch dog enable and security … Thats it.. Come on your copping out to easily …

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Hello @evan1,

TL;DR: Shift to the latest IDE, select a new PIC family member, and recompile the code. If this is not possible, second source the original PIC or give the PIC16F74 a try with no guarantee of success.

Love those old ceramic parts but you always needed two, one in the UV eraser and one in the test project. It’s been 25 years since I’ve programmed one but only a few days since I’ve launched MPLAB.

  • The DM164136 ships with a PIC16F18875.

  • The Curiosity boards are flexible but limited. Each is designed to work with a specific family. For example, I had a similar board that did not like the latest PIC16F13145.

  • MPLAB 6.25 is the latest version (as of 20 Oct 2025).

As for compatibility, there is considerable difference between the SFRs on the PIC16C74 and the PIC16F74. As a general statement the compatibility arrow is in your favor.

Sincerely,

Aaron

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