First power-on

Switch it on. You'll hear a short beep, and the screen says:

-- 6502 BIOS v1.5 --
ENTER=BASIC  ESC=MONITOR

You have about five seconds to choose.

• Press Enter — or just wait — and you get BASIC. This is what you want, nearly always.
• Press Esc and you get the Monitor instead: a much lower-level tool for looking at memory directly. It's a whole chapter of its own, and nothing is lost by ignoring it for now.

Take the default, and a moment later:

6502 BASIC V2.0
30718 BYTES FREE

OK

The five seconds you get to choose. Do nothing and BASIC starts.

What it does in those five seconds

Switch on, and the machine sets the screen up, looks around to see which cards are fitted, and then waits for you.

The OK prompt

OK is the machine saying your turn. Anything you type now gets read when you press Enter. There's no shell, no file manager, no desktop — this prompt is the computer.

30718 bytes free is how much room your programs have. It's about thirty kilobytes, which in BASIC is a lot: a substantial game fits in half of it.

Three version numbers, all different

The ROM contains three pieces of software and they don't share a version number. The BIOS is v1.5 — that's the top line. BASIC is V2.0 — the banner underneath. The Monitor is v1.1, and doesn't announce itself until you go there. Don't be alarmed when they disagree; they're meant to.

What just happened

In the second or so before the splash appeared, the ACE checked itself over: what video hardware is there, is a sound chip fitted, is there a memory card in the slot, is the clock running. Then it set up whatever it found, drew the splash on the screen it had just configured, and handed over to you.

That check is why the machine doesn't sulk when something's missing. No sound chip and the beep is simply skipped. No memory card and the disk commands say so politely instead of hanging. No monitor at all and the whole console moves over to the serial port, so a laptop and a USB-to-serial cable is a complete way to use the machine.

The one thing it can't work around: with neither a screen nor a serial connection there's nowhere to put the prompt, so it stops rather than running blind. If you're seeing nothing at all, that's the first thing to check — see When something's wrong.

Try it

You're at the prompt. Type this:

PRINT 12 * 12

 144

OK

The machine is a calculator, among other things. Now go on to Your first ten minutes and make it do something bigger.