There's also analog EFI, which was rare and expensive and otherwise not great: https://en.wikipedia.org/wiki/Bendix_Electrojector https://en.wikipedia.org/wiki/

There's also analog EFI, which was rare and expensive and otherwise not great: https://en.wikipedia.org/wiki/Bendix_Electrojector https://en.wikipedia.org/wiki/Bendix_Electrojector The early electronic components were not reliable in an underhood environment and were not easily modified as engine control requirements advanced. Most of the 35 vehicles originally equipped with Electrojector were retrofitted with 4-barrel carburetors.