taking me back to creating fliphide, a utility I wrote in the early '90s. It utilized assembly and INT21, guided by "Undocumented DOS"—a book uncovering the OS'

taking me back to creating fliphide, a utility I wrote in the early '90s. It utilized assembly and INT21, guided by "Undocumented DOS"—a book uncovering the OS's undocumented features. This resource was pivotal for crafting an executable (whether .exe or .com didn't matter) that manipulated file attributes, showcasing the power of accessing deeper OS layers not widely known or used.