I define a public variable as pointer array like 'unsigned char idata * OSTsakStackBotton[OS_MAX_TASKS+1];' And I declare it in asm file as 'EXTRN DATA (OSTsakStackBotton)' and access it in this file. Everything is all right in the small model.But when I select the large mode without any modification,I get a lot of errors. *** ERROR L102: EXTERNAL ATTRIBUTE MISMATCH SYMBOL: OSTSAKSTACKBOTTON MODULE: .\Os_cpu_a.obj (OS_CPU_A_ASM) *** ERROR L118: REFERENCE MADE TO ERRONEOUS EXTERNAL SYMBOL: OSTSAKSTACKBOTTON MODULE: .\Os_cpu_a.obj (OS_CPU_A_ASM) ADDRESS: 04BEH What is the problem?