Compaq 386 manual Memory Error Codes

Maintenance and Service Guide 5-31

5.4 MEMORY ERROR CODES

Memory error codes appear when the system detects a memory fault during the Power-On Self-Test (201 or 203 error codes) or as a result of a diagnostic test (203 error codes). The TEST programs attempt to isolate the memory fault to a specific location, then generate a memory error code that identifies the defective system memory board or system memory module to be replaced.

The memory error code points to a specific memory address. The physical location of the memory address depends on the number and type of memory boards installed and the type of memory device used.

The first one megabyte of RAM in the system is mapped into various areas of the system memory map. The common configuration is that the first 640 Kbytes are the base memory. The next 256 Kbytes are used by the COMPAQ Expanded Memory Management (CEMM) Program. The last 128 Kbytes are reserved for system use. The base memory size is configured on the system memory board to 256 Kbytes, 512 Kbytes, or 640 Kbytes. When the base memory size is reduced, the RAM normally assigned to the base memory is mapped into the extended memory space.

Addendum 108431-001 (11-88) to Manual No. 108033-003