Reply 20 of 125, by Bondi
I found another IBM patent. Looks like it directly refers to PCMCIA sound card. https://patentimages.storage.googleapis.com/9 … e/US5768631.pdf
From what i could understand they used a combination of software and hardware to make their PCMCIA sound card work with protected mode games. It's not only TSR but also some sort of controller is involved. I leave this here just in case it's somehow useful for the project.
"Software emulation appears to be the preferred route from a point of ease or economy. However, emulation in this way is restricted to software that is not operated under a protected mode in the DOS operating system used by PC computers. Many exist ing games operate in the DOS protected mode. They will not function properly if used with a pure software emulation of an industry standard audio card. A pure software emulation of an audio card is significantly limited from being fully audio compatible. The combination of hardware and software of the invention provides a significant improvement over the software only solution, mentioned above. in providing a solution to operate successfully within software applications in protected or non-protected modes."