Patch to do what? Install it? You can still use non PNP devices in Windows 7 without a patch. Device manager -> Right click top entry (computer name) -> Add legacy hardware
What like a DIP-switch configured ISA card? PnP = 100% Marketing BS. Nearly everything needs a driver - thus rarely is it "Plug'n'Play" (unless its a trivial USB-HID device).
Even "trivial" USB-HID devices use a driver, most keyboards are done in such a way as to make it trivial because it should be. I never had a problem getting non-PnP devices to work on PnP based operating systems. Had a 386 loaded with them that worked fine under DOS->WFW 3.11->Win95 on the same machine. Not sure about WFW but Win95 claimed to be PnP whorage.
PNP was never supposed to mean "Oh you dont need drivers". I suspect Melchior doesnt know what PnP is supposed to be nor remembers (or was around) for non pnp hardware. Manually setting IRQ and DMA's via jumpers, trying to figure out which were already in use on your system and planning around that.... PnP made all that obsolete and is what it meant by "plug and play" not "dont need drivers!"
+1 Also you just have to bare in mind, while modern devices dont mind sharing an IRQ, legacy devices dont,and if you run out of IRQs you will have problems, allso if your running legacy devices just make sure its IRQ is completely open and not shared by any modern cards (with PNP) that might automatically assighn to that IRQ,regarless of how smart PNP is it still does that often. I can remember back in the day having a high end 486 with ISA, Sound Blaster 16, TV Capture card, Mpeg compression card, 10mbit network card, and a 8meg S3 on Vesa Local bus, and sitting hours trying to sort out IRQ conflicts between the cards and without fail the FDD/IDE controller :/ , wasnt lot of fun....
I loved having IRQ conflicts in Windows 95 for no apparent reason after having everything function just fine the night before! Nothing like having your modem and sound card fight when there are actually enough IRQs to go around. I remember when USB rolled around it went into "Plug 'n Pray" but that may have also been used for PnP ISA/EISA/PCI cards for all I know. http://www.youtube.com/watch?v=Wpj1SgQQ984
plug and pray was PnP in general when it came out. Mostly due to the issues fasman described.... If your whole system was PnP, you were good to go. If you had a mix, it would cause issues that were hard to track down - hence the "plug and pray". Now that hardly anyone uses legacy hardware anymore, its working as intended and people dont realise how good they have it now.
Assembler, what Hardware do you want to use? It probably will work, but the biggest opsticle will be drivers, but if its just legacy "CD Drives" it probably wont be a problem as long as you have a proper controller to run it from...
You should be able to use old CD-Rom drives without any problems on modern operating systems, PnP was only used to remove the problems with IRQ conflicts and remove the need to set them manually as far as i know, do you have a specific piece of hardware you are trying to use?
