|
|
|
| Authored by: Anonymous on Tuesday, June 12 2012 @ 05:27 PM EDT |
The MPEG encoding of video on a DVD is actually a program that is interpreted by
the MPEG decoder, and whose execution yields video data.
This is actually true of almost all compressed data formats -- the compression
is a program which is interpreted by the decompressor.[ Reply to This | Parent | # ]
|
| |
| Authored by: Anonymous on Tuesday, June 12 2012 @ 05:32 PM EDT |
Surely software is data that is executed?
The loom cards are software - they are "executed" by the holes (or
lack thereof) being "read" by the loom and the loom using that
information to decide which threads are raised or not.
By changing the [hole patterns on the] cards, the loom is instructed to do
different things: the loom is the hardware and the cards are the software.
Consider the Acorn BBC micro. There was a program to play tunes that were
stored in memory. Pointing the program's data pointer to the ROM area of the
computer, it played a [weird] tune. So obviously the ROM area contained data
[for music].
However that ROM area was also read by the 6502 CPU and made the whole machine
act as a programmable computer. So obviously the ROM area contained software
[the OS for the machine]!
ergo, Software is data that is executed!
Or to put it another way: data is data and what it REPRESENTS depends upon what
it done with it:
* on a CD, the data represents digitised sound which is "executed" by
the sound program (ie the CD player)
* for software, the data represents the program to be executed - either directly
by the CPU or "interpreted" by another program executed by the CPU
(which these days is often another program executed by a simpler
"inner" CPU).
A software program can be given to the music player, but it may not sound nice;
similarly music data can be given to a CPU, but it may not do anything useful -
it may just "crash" as a buggy program would.
Similarly, I can write a program with pen and paper, but until it is loaded into
memory of a computer it cannot be executed, but if it was never loaded and
executed would that mean it is not software?[ Reply to This | Parent | # ]
|
- No,no,no! - Authored by: Anonymous on Wednesday, June 13 2012 @ 12:08 PM EDT
| |
| Authored by: Anonymous on Tuesday, June 12 2012 @ 05:34 PM EDT |
Stupid question:
What /software/ was executed to create the holes on a loom card?
It is more likely to have been "hardware" in the form of a hole punch
(operated by manually locating where a hole should be and punching it).[ Reply to This | Parent | # ]
|
| |
| Authored by: Wol on Wednesday, June 13 2012 @ 05:54 AM EDT |
Then what is a LISP program?
The difference between "program" and "data" is a distinction
without a difference. As far as the ALU is concerned (ie the bit of the computer
that actually computes), it has no way of knowing that the instruction register
is reading software and the data register is reading data. As far as it is
concerned, data is coming in one end, and going out the other. It has no concept
of instructions and information, of software and data.
And as I said, as far as LISP is concerned, the instructions ARE the data.
That's an elementary, proven, mathematical fact!
Cheers,
Wol[ Reply to This | Parent | # ]
|
|
|
|
|
