Sorry, but USB is talking a protocol. The USB driver in your PC is expecting the device to communicate using this protocol.

So you can't just have the PC send ones or zeroes on the D+ and D- lines and have external logic pick up the transitions and drive external data. You really do need a device supporting USB. Yes, there does exist at least one AVR project with bitbanged USB, but forget about that route - the AVR chip is quite fast so you can't buy the cheapest 8051 chips if trying to match the behaviour.

Bit-banging requires you to have something where the PC can toggle signals on command. The closest you get with a PC is the interface for measuring voltages, temperatures, fan RPM etc. Or you need to buy a PCI board with a printer interface or serial interface. Or get some old PC where you can place your own electronics on the PC or ISA buses and potentially sidestep the OS and instead boot MS-DOS and control the barebone hw directly from your code.

A PC with a speaker output could allow you to toggle the speaker signal, but that is just a single bit so no good for data and clock.