SMARTDRV.SYS is a disk caching program for DOS and Windows 3.x systems. The
smartdrive program keeps a copy of recently accessed hard disk data in memory. When a program
or MSDOS reads data, smartdrive first checks to see if it already has a copy and if so supplies it
instead of reading from the hard disk.
Memory Management
• First 640k is Conventional Memory
• 640k to 1024k is Upper Memory
• Above 1024k is Extended Memory
• HIMEM.SYS is loaded in CONFIG.SYS as the first driver to manage the Extended
Memory are and to convert this to XMS (Extended Memory Specification). The first 64k of
extended memory has been labeled High Memory (HMA). DOS can be put here by putting
DOS=HIGH in CONFIG.SYS.
• EMM386.EXE is loaded in CONFIG.SYS after HIMEM.SYS has been successfully
loaded. This is used in the hardware reserved 384k of space in upper memory (640k-1024k)
and creates EMS (Extended Memory Specification).
• Virtual Memory relies upon EMS (therefore EMM386.EXE) and uses hard disk space as
memory.
• Memory control commands
smartdrive program keeps a copy of recently accessed hard disk data in memory. When a program
or MSDOS reads data, smartdrive first checks to see if it already has a copy and if so supplies it
instead of reading from the hard disk.
Memory Management
• First 640k is Conventional Memory
• 640k to 1024k is Upper Memory
• Above 1024k is Extended Memory
• HIMEM.SYS is loaded in CONFIG.SYS as the first driver to manage the Extended
Memory are and to convert this to XMS (Extended Memory Specification). The first 64k of
extended memory has been labeled High Memory (HMA). DOS can be put here by putting
DOS=HIGH in CONFIG.SYS.
• EMM386.EXE is loaded in CONFIG.SYS after HIMEM.SYS has been successfully
loaded. This is used in the hardware reserved 384k of space in upper memory (640k-1024k)
and creates EMS (Extended Memory Specification).
• Virtual Memory relies upon EMS (therefore EMM386.EXE) and uses hard disk space as
memory.
• Memory control commands
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