As you can see from this web site, I carry a lot of equipment imported from the USA. Why would you be interested in an American unit? Basically the rules of supply and demand mean that I can get them more readily in the US than in Australia, and I can sell them cheaper than comparable Australian units. “Australian Delivery” TRS-80s (mean TRS-80s manufactured in Fort Worth, TX to Tandy Australia / InterTAN specs) sold in relatively small numbers compared to their American brothers and are very hard for me to locate in Australia and are usually in poor (ie. high mileage) state requiring complete rebuilds by me in order to sell them. US units, on the other hand, have often had much less use and need less work by me to make them ready to sell, so I can ask less for them.
Australia delivery machines should probably be left unmodified for posterity and I encourage anyone buying a TRS-80 to modify it with the myriad of customizations out there to consider attacking a US machine with your soldering irons rather than local machines. But that’s just my opinion. Of course US machines can in some cases be upgraded to Australian 240V power supplies for a cost, but I have found in my experience that those cheap 240-120V Step Down converters you can buy on eBay work very well. My own workshop has a $29 300W step down connected to a TRS-80 Line Filter (basically a US 8-outlet power board) which is connected to my Model 4D, a hard drive, and whichever other US TRS-80s I happen to be working on with no sign of the capacity of the cheap Step Down being overloaded.
DIFFERENCES BETWEEN US and AUSTRALIAN TRS-80s:
Model I: US power supplies are smaller and fit inside the Expansion Interface, Australian power supplies are larger and don’t fit in the EI.
Model I: some machines (well, most) have an additional cable between the KB and EI making the keyboard and EI a matched pair. The mod is called the DIN-cable mod.
Model III: virtually the same machine in both countries except US models are fitted with twin 120V power supplies. RS232 was always an option on all Model IIIs.
Model 4: non-gate-array machines have B&W monitors, and keyboards by Maxi-Switch, optional RS232, as well as a 120V power supply. By contrast Australian non-gate-array M4s had green phosphor monitors, ALPS keyboard, RS232 as standard, and a 240V power supply.
Model 4: Gate-array machines are virtually the same in either country, both came with a green phosphor monitor and a cheaper membrane action keyboard, and 120V power supply. RS232 is standard because its built onto the motherboard now.
Tandy Model 4D: never sold in Australia but as the last and best TRS-80 it has a very high quality monitor, ALPS keyboard, double sided disk drives, and naturally a 120V power supply.
Model 4P: non-gate-array 4Ps have a B&W monitor, but are otherwise the same as Australian non-gate 4Ps, other than the 120V power supply.
Model 4P: gate-array 4Ps in both US and Australian models feature a green phosphor monitor but otherwise are the same machine except for the 120V power supply in the US versions.
Hard drives: TRS-80 hard drives have a Model 4 power supply installed and an A/C powered cooling fan; 120V for the US market and 240V for the Australian market. Care must be taken to replace the fan with a 240V one if upgrading the power supply.
Color Computer 1 and 2: I never sell US Coco 1s and 2s because they are NTSC only and don’t work properly on Australian PAL TVs. However if someone really does want one I’m happy to do the import.
Color Computer 3: I may import these occasionally because they can be used with a monitor, but remember, like the CC1 and 2, the CC3 won’t work properly on Australian PAL TVs.