Keyboard Wedge Connection
With the popularity of the PC and its standard keyboard interface, it became ever easier to connect physical hardware to a PC and so there was commercial demand similarly to reduce the complexity of the associated software. "Keyboard wedge" hardware plugged between the PC and its normal keyboard, with characters from the barcode scanner appearing exactly as if they had been typed at the keyboard.
Keyboard Wedge Scanners are all discontinued.
For replacement models, please refer to USB Barcode Scanners: https://www.marsonscan.com/products/Handheld_Scanners/