Recovering the ROM of an IBM 5100 using OCR (among other things)

[Kevin McQuiggin]

In the early days of cyber crime (it was called “computer crime” back in the 1980s), fraudsters would purchase an aerosol spray with tiny metal particles in it (I forget what the specific valid use case was, but it was legitimate), and apply the spray to the mag stripe on the back of credit cards, then visually read out the bits with a magnifier.  1s and 0s oriented the tiny metal bits orthogonally, and this could be observed.  Then they would program card blanks with the recovered mag stripe data.  

Mag stripe readers were expensive and hard to acquire in those days, so this was the chosen method of recovering track data from credit cards.

I was a police detective investigating “Stone Age”, i.e. pre-Internet cyber crime in that era, and saw this for myself by actually spraying a card and then reading out its data.  

Very creative criminals!  

Kevin




> On Jun 27, 2019, at 7:30 AM, Noel Chiappa via cctalk <cctalk at classiccmp.org> wrote:
> 
>> From: Liam Proven
> 
>> This is *epic*.
> 
> Indeed. I was blown away by the complexity of his technique for reading
> the digits.
> 
> I can't believe there wasn't a much easier technique, though, e.g. using a
> logic analyzer and a small program to read through the ROS!
> 
> Perhaps the challenge of doing it his way entertained him, though, like
> George Mallory's famous line about climbing Everest.
> 
> 	Noel