You
can use the old keyboard
and the mouse. The problem I discovered is the lack of “legacy” ports on the iMac. It has the absolutely amazing SSD ‘drive’ but no internal HD. So the two formerly FireWire connected backup drives now need USB cables (plural, because usb is not for networking or Daisy’s-chained drives). That’s 2 USB ports gone. Without an internal drive, the 512Gb SSD can’t hold all the Sytstem, files & apps that were on the old Tb drive, so, one more USB drive connected. That leaves one lonely USB port on the iMac. Obviously, I have a 4-port USB3 hub connected to that for the printer, scanner, the old Mighty Mouse leaving room for the USB to Lightning cable to recharge the new non-wired keyboard and trackpad. Fortunately the hub still has a charging only port for the iPhone and the Apple Watch I rarely wear.
There
are two Thunderbolt 3 ports, but those kinds of devices are still very expensive and probably not long for this Apple-only world. So, I had little choice but to use the non-wired kb, especially with several of its keys starting to fail... just details I failed to consider thoroughly enough... If this Mac lasts as long has its predessor, I probably won’t remember what I learned this time around, either!
