About 10 years ago I was working for a French bank, for a small regional team to develop internal tools. The only way we could access the core database was thr

About 10 years ago I was working for a French bank, for a small regional team to develop internal tools. The only way we could access the core database was through a mainframe terminal emulator only available on client PCs across the internal network. It was basically an old school terminal based UI where you had to enter specific codes and sequences of keys to navigate. It was not supposed to be automatable, and we did not have permission to deploy any executable to computers on the network. However, we found a way to plug into it by calling an obscure DLL via Internet Explorer's ActiveX. From there, we had access to only two functions: one to send a sequence of key strokes to the emulator, and another which was basically getString(x, y, length). We built whole applications using this database, only via those two functions, which led to giant procedures for each query we had to do. It was terrible, unstable and slow, and broke at every update, but it did the work.