The "NO" setting lets the BIOS handle PnP. The YES option lets Windows/DOS handle PnP.

Some cards might initialize PnP regardless of the state (generally SB16 and YMF719) because those might not have PnP support for Windows - IIRC certain Creative cards didn't have PnP functionality outside the BIOS so those are usually initialized regardless of the setting, yet appear non-PnP to Windows.

Later version SB cards used CTCM and DIAGNOSE to initialize, and then configure themselves.

Windows was able to do the job instead, after about win95 osr2.

'PnP Bios' will configure *any* PnP card though. Often times incorrectly. It was often necessary to strongarm the bios's resource pool to stop it from assigning incorrect resources to cards.

(Eg, 'NO, DO NOT put that PnP IDE controller on IRQ 5. It MUST go on IRQ 10, stop being an idiot.' And pals.)

PcBytes wrote on 2025-03-28, 16:04:

The "NO" setting lets the BIOS handle PnP. The YES option lets Windows/DOS handle PnP.

well that's what i said... in theory anyway.

PcBytes wrote on 2025-03-28, 16:04:

Some cards might initialize PnP regardless of the state (generally SB16 and YMF719) because those might not have PnP support for Windows - IIRC certain Creative cards didn't have PnP functionality outside the BIOS so those are usually initialized regardless of the setting, yet appear non-PnP to Windows.

what cards are these? an AWE64 should be fully pnp compatible, including to windows 95, and it's initialized regardless of that setting. that's why i have doubts about that setting - unless it was changed on later boards. in theory the setting should only affect ISA cards, and ISA generally disappeared from mainboards after 2001 or so. however this source suggests the setting also being ACPI-related. are there ISA-less boards that have this setting in BIOS?

by the way, if you referred to "software configurable" cards like the CT2290, in DOS these are indeed initialized via diagnose /s instead of CTCM. i can't remember offhand if those cards will be enumerated by such a pnp bios.

auron wrote on 2025-03-28, 17:00:

PcBytes wrote on 2025-03-28, 16:04:

Some cards might initialize PnP regardless of the state (generally SB16 and YMF719) because those might not have PnP support for Windows - IIRC certain Creative cards didn't have PnP functionality outside the BIOS so those are usually initialized regardless of the setting, yet appear non-PnP to Windows.

what cards are these? an AWE64 should be fully pnp compatible, including to windows 95, and it's initialized regardless of that setting. that's why i have doubts about that setting - unless it was changed on later boards. in theory the setting should only affect ISA cards, and ISA generally disappeared from mainboards after 2001 or so. however this source suggests the setting also being ACPI-related. are there ISA-less boards that have this setting in BIOS?

by the way, if you referred to "software configurable" cards like the CT2290, in DOS these are indeed initialized via diagnose /s instead of CTCM. i can't remember offhand if those cards will be enumerated by such a pnp bios.

CT2770 is one, I recall ASUS boards always initializing it regardless of the PnP setting in BIOS.