Upravo je test koji si pustio definitivno pokazao da je sve OK. Teško da bi bilo šta radilo i sekundu sa takvim odstupanjima bitnih parametara! Jednostavno, negativni naponi su tu radi kompatibilosti, a iole modernije ploče ih ni ne koriste. Prelistao sam čika-Milera i on kaže:
If you look at a specification sheet for a typical PC power supply, you can see that the supply generates
not only +3.3V, +5V, and +12V, but also –5V and –12V. The positive voltages seemingly power everything
in the system (logic and motors), so what are the negative voltages used for? The answer is not
much! Some of the power supply designs, such as the small form factor (SFX) design, no longer include
the –5V output for that reason. The only reason it has remained in most power supply designs is that
–5V is required on the Industry Standard Architecture (ISA) bus for full backward-compatibility.
Although –5V and –12V are supplied to the motherboard via the power supply connectors, the motherboard
normally uses only the +3.3V, +5V, and +12V. The –5V is simply routed to the ISA bus on pin
B5 so any ISA cards can use it, even though not many do today. However, as an example, the analog
data separator circuits found in older floppy controllers do use –5V.
The motherboard logic typically doesn’t use –12V either; however, it might be used in some board
designs for serial port or LAN circuits.