MSCDEX is an example where you need to conform to the interface it expects: it requires a device name to be passed to it, so the low-level CD-ROM driver pretty much has to be a. I suppose installing devices is one way to enable other software to communicate with your driver, but you could just implement a TSR which hooks an interrupt, so I'm not sure when it's particularly important to actually install a device except when you need to conform to a particular interface. the ones you see in the output of the MEM /D command. SYS drivers seem to be necessary to install actual 'devices' as seen by DOS, i.e. I assume that either way there will be a PSP but it won't have an environment of its own in older DOS versions, it will just point to the global one or something?Īnother difference is that as far as I know.
With DOS 6.0 an environment is created, so the extra memory is no longer gained by using the INSTALL command In the past, INSTALL may have saved you a little bit of memory because it does not create an environment when it loads a program.
