FDD controller for Sinclair ZX Spectrum clones

ZX Spectrum Drive Controller of Leningrad and other compatible clones ZX Spectrum.ZX Spectrum controller drive domestic clones (Himac), complete with 3 programmed PLD.The controller is directly suited to clones 48K / 128K with a connector according to the NETI standard.To other clones you need to connect accordingly through an adapter or wires. Limitations of use:Leningrads and other similar clones.The controller will not work in clones in which the processor data bus is connected to the video controller data bus (FF port), respectively, will not work in branded Sinclair ZX Spectrum 48K and 128K for the same reason.The controller will not work in Delta-128K on a ULA chip, I suspect that the reason is the same.2. For 128K machines, the discharge of D4 port 7FFD is not monitored, therefore this signal is necessary on the system bus.Ideal for Leningrad and other similar clones.