top of page
An ISA computer expansion card_edited.png

Build an intelligent Thinking Cashier

Thinking Cashier is an ISA computer expansion card that transforms a regular PC into an intelligent Point of Sale (POS).

Thinking Cashier Story

As the Visual Office (VO) customer base expanded, some of our customers requested it integrate with their stores. As we studied cashiers' capabilities, I thought we could offer more functionality if cashiers were intelligent and user-friendly. Being able to search for a product by an approximation of its name or characteristics would smooth the sales process. From inception, VO was designed as a modular system, so it would also be easy to upsell modules such as inventory control to the stores.

Lior Dor

My father, Lior Dor, designed the electronics and printed circuit board, and I authored the desktop and OS kernel software — the Thinking Cashier was born. It is an ISA computer expansion card that transforms a regular PC into an intelligent Point of Sale (POS). We manufactured it in Israel.

This was a commercially successful project, but my splendid gain was personal: working with my father on technical matters and traveling with him as we built the company's supply chain and manufacturing process. Few are that lucky.

The ISA card provides hardware interfaces to a cash drawer, 40-column printer, shopper LCD display, external power supply, a secure-safe (encrypted and locked) non-volatile memory, and a real-world clock that prevents date and time manipulations.


Approval by the IRS

The safe-locked memory held encrypted data that was not accessible or viewable unless a virtual key was provided; even after opening the lock, the data was not present as a file on disk, nor was it present in memory, and thus is not amenable even to external hacking tools that can access typical areas of memory. Similarly, the user can deliberately change the regular computer system's clock. Still, the real-world clock we developed allowed the Thinking Cashier to use our clock services and override the regular computer clock. We chartered new paths, operating a PC as a POS. We knew we were on new ground when the Israel Internal Revenue Service (IRS) approved the PC + card as a PoS, predominately because of our tamper-free memory vault and real-world clock design.

Key components

  • Dallas Semiconductors DS1307

  • Dallas Semiconductors DS1210

  • Intel x86 Assembler programming language

bottom of page