How security holes happen

[MRAB]

On 2014-03-06 01:24, Mark H. Harris wrote:
> On Wednesday, March 5, 2014 6:24:52 PM UTC-6, Dennis Lee Bieber
> wrote:
>> I must have had a deprived life...
>>
>> The only "debug" on a home system I ever used was the one in
>> LS-DOS. And even then, it was only because an OS update disk
>> arrived with a bad sector and could not be copied.
>
> Not many people realized what they had in front of them. The only
> reason you might is if you 'grew up' on a system that required
> machine coding;  like the Wang 700 series, or the MITS Altair 8800,
> or the VIC 20 with VicMon.
>
> I grew up with all three. So, before I ever learned a line of BASIC I
> was coding machine language (not assembler) on the three platforms
> above... the wang used integrated circuits, but had to processor
> chip;  the MITS used the very first 8080 chip from Intel, and the VIC
> 20 used the 6502 from Motorola.
>
The 6502 came from MOS Technology. Motorola made the 6800.

> My first personal computer (I did not own it, it was temporarily
> loaned to me) was the VIC 20.  It only had 5k of memory, so anyone
> who did any real programming on it purchased the VicMon cartridge
> which was a 'machine language monitor'. It was "DEBUG.COM" for the
> VIC 20.
>
5K? Luxury! I started with the Science of Cambridge Mk14. Including the
RAM on the I/O chip, it had 640 bytes.

> When I got the first copy of DOS on floppy and saw DEBUG.COM I knew
> instantly what it was... a machine language monitor system for
> reading and writing machine code (8086 / 8088) in memory, or to disk
>  sectors, or to disk as a file-name.  It wasn't just a
> debugger---hardly! It was (and still is, yes, I still use it) a
> simple clean full-blown machine language monitor capable today just
> as then, to build sophisticated applications with 1's and 0's/
>
> It was also my cup of tea, as it were.  The folks who used the MITS
> Altair 8800 hated punching code in by hand; gets old fast.  But not
> for me. I loved it, because I was as interested in the 8080 processor
> as I was in writing programs for it; it was great fun experimenting
> with memory and the processor.
>