Diff- Pascal for Windows vs Pascal for DOS

What are the differences between Turbo Pascal for Windows V1.5 and Turbo
Pascal for DOS V7.0?  I have an application that was written under Turbo
Pascal for DOS V5.0 that writes graphics directly to the screen BIOS.  
Windows NT and Windows 95 apparently do not support this capability.  Do
I need to upgrade to Pascal for DOS V7.0 to get the DOSAPI calls
necessary for Windows NT et. al. or will TP for Windows work as well?

Thanks,

Jim Goon   J...@msg.ti.com