- supplement (2019/4/25).
I made this post as an image of the "RaSCSI" project.
It connects PiZERO's GPIO interface to a SCSI connector and emulates peripherals.
It is necessary to convert the voltage of "SCSI bus" to that of GPIO, but there are methods such as voltage division by using resistors or voltage conversion logic ICs. I think that it is a project that is known to be localized to various people, such as termination impedance.
General questions about user hardware work
1. I would like to know the "Edge Connector" of 'ZX Spectrum expansion bus' and the standard of cartridge size.
2. Is the expansion bus of 'ZX Spectrum Next' the same standard as the conventional ZX Spectrum such as power capacity and "audio input" pins for example? (unpublished)
3. My opinion. Rather than designing a circuit such as an "address decoder" to produce an extension unit using a microcomputer or an interface chip, it would be more expensive to directly connect a microcomputer to the ZX bus.
For example, if you monitor the ZX bus with 'Raspberry Pi ZERO(or A+)' GPIO and make software for "expansion unit emulator" is inexpensive and versatile?