The 8008 was: Blinky lights WAS: The SR71 Blackbird was designed ENTIRELYwith slide rules 686

For what it's worth, I suspect the Australian answer may be more restrictive than the American one, simply due to the amount inherited from the British system - where legal tender is defined quite narrowly.

In the UK as a whole, coinage is legal tender in amounts dependent on the denomination. Coppers are valid up to 20p, low-denomination silver (5p and 10p) valid up to £5, high-denomination silver (20p and 50p) valid up to £10, and pound coins (£1, £2 and presumably the odd £5) are valid to indefinite amounts. 1 Gold coins are still legal tender for any amount, if of an acceptable weight, but I would be astonished to hear of one having circulated; commemorative coins (sometimes?) ditto, depending on the proclamation when they were issued. 2

Bank of England notes are fully legal tender in England and Wales 3. No current banknotes are legal tender in Scotland (or Northern Ireland) - although an interesting footnote is that Bank of England notes valued below £5 would be, were there any. This wasn't affected by the note-coin replacement, so were a £1 or £2 note to be issued by the BoE, it would become legal tender throughout the UK. During the War, for reasons I presume of simplicity, the Scottish-issued banknotes 4 were made legal tender throughout the UK; this ceased in '46.

(Further random footnote: the Scots pound, which ceased to exist in 1707, is still a valid concept in Scottish law; it's valued at about £12 Scots to £1 British.)

1 The Scottish Parliament seems to think that there are different limits for some of these in Scotland, but AIUI they're in error.

2 There's a £2 commemorative coin from 1985, for example, which was declared legal tender.

3 Which is, for most such purposes, one legal enbreasty that just happens to sound like two...

4 Which are only Scottish by coincidence, but that's another story.

-- -Andrew Gray