Hi, I see no comments since 4 years, but I tried to contact for using 1 port for a new interface we're developing to emulate keyboard but require an IN/OUT port for the mode "redefine keys" so one 0xXX3B port would be a nice option. We have done initial tests using 0xF73B but maybe this ZXI standard was developed with other ports in mind for keyboard interfaces of something similar to this. Using 0xxFE or even port is not an option as the redefine keys option can be manage trough standard speccy keyboard.
About the interrupt triggering. Devices that are not im2 aware should not drive any value on the data bus during an intack cycle. Instead they should rely on the expansion bus pullups to ensure a 0xff value is read. Doing otherwise would be incompatible with devices that are im2 aware. The zx next will be an im2 aware computer and there are original spectrum peripherals that operated in the im2 mode, eg the amx mouse. In general, any device using standard zilog peripheral ics can be im2 enabled.
Email contact through zxdesign.info doesn't seem to have worked so I will try here.
We'd like to add an eight channel ctc to the zx spectrum next using ports 0x183B through 0x1F3B. There are no conflicts currently according to the page as it is today and I've spoken to Jan (mb03) about it already. I think he's the only other developer actively creating new hardware at the moment.
So I'll go ahead with this unless I hear otherwise.
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Hi, I see no comments since 4 years, but I tried to contact for using 1 port for a new interface we're developing to emulate keyboard but require an IN/OUT port for the mode "redefine keys" so one 0xXX3B port would be a nice option. We have done initial tests using 0xF73B but maybe this ZXI standard was developed with other ports in mind for keyboard interfaces of something similar to this. Using 0xxFE or even port is not an option as the redefine keys option can be manage trough standard speccy keyboard.
Thanks in advance
Mad3001
About the interrupt triggering. Devices that are not im2 aware should not drive any value on the data bus during an intack cycle. Instead they should rely on the expansion bus pullups to ensure a 0xff value is read. Doing otherwise would be incompatible with devices that are im2 aware. The zx next will be an im2 aware computer and there are original spectrum peripherals that operated in the im2 mode, eg the amx mouse. In general, any device using standard zilog peripheral ics can be im2 enabled.
Email contact through zxdesign.info doesn't seem to have worked so I will try here.
We'd like to add an eight channel ctc to the zx spectrum next using ports 0x183B through 0x1F3B. There are no conflicts currently according to the page as it is today and I've spoken to Jan (mb03) about it already. I think he's the only other developer actively creating new hardware at the moment.
So I'll go ahead with this unless I hear otherwise.