So, I have decided to upgrade to an audio interface with midi ports - the Behringer https://www.thomann.co.uk/behringer_umc1820.htm which appears to have 8 instrument-input channels. It will replace a Yamaha AG03 (3 channels), chained to a Behringer Xenyx 802 (4 instrument-input channels).
I need to use midi cables to join up the three midi devices, that have the following ports:
~ Kurzweil SP76 (midi In, midi Out)
~ E-MU Classic Keys (midi In, midi Out, midi Thru')
~ UMC 1820 (midi In, midi Out)
I assume that it will be
1. Kurzweil SP76, midi Out >
2. midi In of the E-MU Classic Keys / midi Out of the E-MU Classic Keys>
3. midi In of the UMC 1820.
And if I want the PC to play the keyboard, I take the advice of @BigRedX :
4. That is, midi Out of the UMC 1820 > midi in of the Kurzweil SP76.
So, I will need three midi cables?
_Behringer UMC1820 – Thomann UK.html