K7S5A v1.x maximum CPU and HDD supported information as below,
HDD:250G
CPU: AMD Duron 200Mhz FSB CPU - 950 AMD Duron 266Mhz FSB CPU - 1800
           AMD Morgan 200Mhz FSB CPU - 1.3G 
           AMD Athlon 200Mhz FSB CPU - 1.4G AMD Athlon 266Mhz FSB CPU - 1.4G
           AMD Palomino 266Mhz FSB CPU - 1.2G 
           AMD Athlon XP (0.18u) 266Mhz FSB CPU - 2100+ AMD Athlon XP (0.13u) 266Mhz FSB CPU - 2600+

K7S5A can't support DDR333 memory because of SiS735 chipset specification.

BIOS version 02/02/06 or later will solve this issue.

Owing to K7S5A hardware specification, S3 mode cannot be supported.

ECS standard models with AMI BIOS only provide for 4 second delay as a default setting on the Power Button / Soft Off item.

The attached file is BIOS support PXE Boot ROM

• get_app Download Link

Yes. K7S5A supports Athlon XP 2200+.

No, the K7S5A does not support AMD Sempron CPU.

This model support maximum HDD capacity up to 250GB.