Host Signal Processing (HSP) is a term used in computing to describe hardware such as a modem

Modem

A modem is a device that modulates an analog carrier signal to encode digital information, and also demodulates such a carrier signal to decode the transmitted information. The goal is to produce a signal that can be transmitted easily and decoded to reproduce the original digital data...

 or printer

Computer printer

In computing, a printer is a peripheral which produces a text or graphics of documents stored in electronic form, usually on physical print media such as paper or transparencies. Many printers are primarily used as local peripherals, and are attached by a printer cable or, in most new printers, a...

 which is emulated (to various degrees) in software. Intel uses the term Native Signal Processing (NSP). HSP replaces dedicated DSP

Digital signal processor

A digital signal processor is a specialized microprocessor with an architecture optimized for the fast operational needs of digital signal processing.-Typical characteristics:...

 or ASIC

ASIC

ASIC may refer to:* Application-specific integrated circuit, an integrated circuit developed for a particular use, as opposed to a customised general-purpose device.* ASIC programming language, a dialect of BASIC...

 hardware by using the general purpose CPU of the host computer.

Modems using HSP are known as winmodems (a term trademarked by 3COM / USRobotics, but genericized) or softmodem

Softmodem

A Softmodem, or software modem, is a modem with minimal hardware capacities, designed to use a host computer's resources to perform most of the tasks performed by dedicated hardware in a traditional modem.A Softmodem is also referred to as a Winmodem because the first commercially available...

s. Printers using HSP are known as GDI printers (after the MS Windows GDI software interface), winprinters (named after winmodems) or softprinters.

The Apple II

Apple II

The Apple II is an 8-bit home computer, one of the first highly successful mass-produced microcomputer products, designed primarily by Steve Wozniak, manufactured by Apple Computer and introduced in 1977...

 floppy drive used the host CPU to process drive control signals, instead of a microcontroller

Microcontroller

A microcontroller is a small computer on a single integrated circuit containing a processor core, memory, and programmable input/output peripherals. Program memory in the form of NOR flash or OTP ROM is also often included on chip, as well as a typically small amount of RAM...

. This instance of HSP predates the usage of the terms HSP and NSP.