[filmscanners] (OT) Firmware

["Bob Shomler" <bob@shomler.com>]

>I believe a more succinct definition is "firmware is software that is
>embedded in hardware", and is not dynamically loaded from a hard disk etc.
>The BIOS in your computer is considered "firmware".

I think the "embedded code" you mention (that implements machine function) is 
at the heart of all definitions.

Some dictionaries (see dictionary.com) define firmware to be software that is 
stored in read-only memory (ROM) or programmable ROM (PROM), as does the online 
Encyclopaedia Britannica:

  software programs and procedures that are permanently stored in a
  computer's memory using a read-only (ROM) technology are called
  firmware, or “hard software.”

However firmware also is used as a synonym for microcode, and microcode has in 
the past sometimes been loaded from a disk drive.  Indeed the original "floppy 
disk" in the late 1960s or early 1970s was an 8-inch (as I recall) disk that 
held microcode for an IBM DASD (hard disk) controller.

A functional definition of firmware as microcode might be 1) "hardware-specific 
embedded code that implements externally usable functions of a system or 
subsystem (e.g., instructions or macro-instructions of a processor); 2) 
embedded code -- sequences of microinstructions -- provided as part of a system 
or subsystem as an alternative to hard-wired circuitry to implement certain 
functions of a processor or other system component.  (2) is expanded from a 
definition of microcode in the IBM Dictionary of Computing.

One definition of firmware in the IBM Dictionary of Computing (Tenth edition, 
August 1993): "An ordered set of instructions and data stored in a way that is 
functionally independent of main storage; for example, microprograms stored in 
a ROM."  That dentition is credited to The "Information Technology Vocabulary"  
 drafts and working papers (ISO/IEC/JTEC/SC1) -- working papers meaning that as 
of mid-1993, "final agreement has not been reached among the participating 
National Bodies of SC1."

Bob Shomler

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