IBM 5150 PC

Brian Lanning brianlanning at
Wed Jul 8 23:08:18 CDT 2009

On Wed, Jul 8, 2009 at 10:40 PM, Ethan Dicks<ethan.dicks at> wrote:
> Yes.  Especially if you are used to DOS 5 or DOS 6, DOS 3.3 won't feel
> too "odd", but takes up less memory than the newer versions.

I had an original 5150.  If I remember correctly, mine came with 2.1.
(this was the 8th grade for me)  Then when I was at school, i snuck
into the nurse's office and sat down at one of two XTs they had.  (Not
sure why they were in the nurse's office).   I was in awe over the
hard drive, which was the first I had ever seen.  I was also excited
about finding a new version of DOS (3.3) since debug had an assembler!
 Debug in 2.1 would only unassemble.  I managed to make a bootable 3.3
floppy that worked on my home machine.  Now you could type in opcodes
and it would translate them into bytes.  Up to that point, I had been
unassembling random memory looking for the instruction that I wanted,
then writing down the bytes, and reverse-engineering the address
offset parts of the machine language instructions, then typing the
bytes back in to write programs.  I managed to write some fairly
rudimentary programs by using just the assembler in debug.

The programs were silly and mostly useless, but it was good experience
though.  Years later at university, I had an assembly language class.
I was delighted when the professor switched it from system/370 to
intel assembly.  I slept through the class and got an A.

And to think that my parents were very hesitant to buy a computer for
me, convinced that I would only use it to play games.  Later, I worked
for a year and a half making minimum wage to save money to buy an
amiga.  They wouldn't spend a dime to help me with that computer
either, since everyone knew it was a game machine.  I played a lot of
games on it, but it also taught me 68000 assembly and this useless
skill called C.


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