Pepův web

Josef Bláha

TwinCalc, calculation and billing software

TwinCalc is a calculation and billing system for the printing company Tiskárna Twin. I developed the software from 2004 to 2007, while working for RNDr. Jiří Dvořák who also owns the copyright. As for 2014, the system is still used by the company.


  • A multi-user system with Windows client application with simple wizard-like navigation.
  • Customer and contact management.
  • Price calculations for orders based on number of copies, used paper, printing techniques etc.
  • Invoice management, due date monitoring.
  • Bill of delivery management.
  • Cash desk management.
  • Export and printing of orders, invoices, bills of delivery, cash receipts etc.
  • Simple statistics of incomes.
  • Archive of legacy orders.
  • User authentication for restricted operations.
  • Automatic database backups.

Project status

Status Finished
License Proprietary


Application window with main menu
TwinCalc main menu
Application window showing one step of the order calculation
One step of order calculation


  • File-based central Microsoft Access database.
  • Windows application created in Visual Basic 6.0.