I have been using the Keil tools for a long time and decided to try uVision for the first time and now have 3 projects. 2 hum along just fine, but in the 3rd I get "warning L1 unresolved external symbol" and "Warning L2 refrence made to unresolved external" both followed by "SYMBOL: WRITETOFLASH" I have cut the module containing the reference to the bare minimum: PUBLIC WriteToFlash FLASHIT SEGMENT CODE RSEG FLASHIT WriteToFlash: ret end In this project the 3 little brown squares I see next to "target 1" on all 3 projects appear next to the name of the above file. What is wrong ? Erik
The _ in front of the function name indicates that the arguments are passed in registers. Refer to the section titled, "Interfacing C Programs to Assembler" in the C51 Compiler User's Guide. The _ is explained there under Function Parameters. This is also described in the following knowledgebase article: http://www.keil.com/support/docs/712.htm Jon