@Rod S - Since you have an older ZW and powerhouses and one powermaster, if you you want to do is run locomotives in conventional mode, you have all you need for ONE THROTTLE on the ZW or one powerhouse. If you want to run multiple loops, you'll need another powermaster or two, but they're relatively cheap. I bought several for $20-$30 a few years back. That's still your cheapest option for running conventional trains as compared to upgrading to Legacy, a ZW-L, etc. The powermaster cables also come with a fast-blow fuse which provides the protection you'd need for any modern engines with electronics. Remember, this enables you to control track voltage, not the engine in command mode.
I saw that you mentioned command control of accessories. That route will require the Legacy or older TMCC command base and an accessory controller.
