[OFF-TOPIC] It is true that is impossible write in binary code, the lowest level of programming that you can write is in hex code?

[Dave Angel]

françai s <romapera15 at gmail.com> Wrote in message:
> I intend to write in lowest level of computer programming as a hobby.
> 
> It is true that is impossible write in binary code, the lowest level
> of programming that you can write is in hex code?
> 
> What is the lowest level of programming computers that you can write ?
> 
> Is binary code?
> 
> Is hex code?
> 
> Is another machine code? Honestly do not know if it is true that there
> is another machine code beyond the binary and hex code.
> 
> Is Assembly?
> 

You have to start somewhere. The lowest practical level is called
 hardware. If you're going to ignore that, then you presumably
 have some particular hardware in mind. If you're talking the
 Intel Pentium, you've already skipped the lowest level, because
 Intel has already done it (microcode ) and sealed it inside the
 chip.

Many years ago I wrote microcode for a living,  and on some of our
 machines it was buried in ROM, while in others it was changeable
 and loaded at boot time. In any case, customers didn't usually
 get documentation or tools for changing it. There probably are
 still processors around that have changeable microcode
 available.

You may ask what is Microcode? It's the code that tells the real
 hardware what to do with that binary "machine code" that people
 call machine code. You don't really think that there is hardware
 to do a trig function,  do you?

So once you pick a processor, if you can't write the microcode, 
 what's the lowest level? Toggle switches is probably it, because
 anything else has gobs of software running before you hit your
 first key. Keyboards were once hardware, but probably any recent
 keyboard has more code in it than my satellite navigation program
 written in 1973.

Of course toggle switches on the console are probably binary, but
 the first IBM machines had hex rotary switches on their
 console.

There's no important difference between binary and hex; you do
 those conversions in your head while toggling stuff
 in.

Now if you don't have a console then you have to go up a level, 
 and use some form of console. We used punched paper tape as the
 next level up, and hex punched cards next. I suppose you'll have
 to use a console,  with some kind of monitor echoing your
 keystrokes onto a screen. No tty for you?

Next level up is to have some form of operating system running. 
 You might even use a system call to output a character to your
 terminal. No machine language instruction for that.

And so on.

Assembly is a low level language that is pretty much translated,
 each line of text into one mahine instruction. Usually the
 printout can show the results in hex or octal, but you can
 trivially convert in your head to binary for those toggle
 switches or whatever.  Or use the executable that your assembler
 and linker produce. But by now you're using lots of os services, 
 reading and writing files, displaying stuff, printing to a dot
 matrix or daisy wheel printer.

Pick your level, there are dozens, and I've used most of them. But
 the distinction between binary, octal, and hex is too minor to
 mention,  except you specifically asked.

HTH

-- 
DaveA