Showing things

PRINT is the statement you'll type more than any other. It's worth ten minutes.

Semicolon or comma

Those two separators are the whole of it. A semicolon joins things up tight:

PRINT "TOTAL:"; 42

TOTAL: 42

OK

A comma jumps to the next column:

PRINT 1, 2, 3

 1             2             3

OK

Columns are 14 characters wide. Three of them fit across the ACE's 40-column screen, and a fourth wraps onto the next line — which looks like a bug the first time it happens and isn't.

Where a comma sends the next thing. It is why columns of numbers line up without any effort, and why a fourth item drops onto the next line.

Holding the cursor

End a PRINT with a semicolon and the next one carries on where it left off:

10 PRINT "WORKING";
20 PRINT ".";
30 PRINT ".";
40 PRINT " DONE"

RUN
WORKING.. DONE

OK

PRINT on its own prints nothing and moves down a line — which is how you get a blank line.

Putting things exactly where you want them

TAB(n) moves to column n, counting from the left edge of the line. SPC(n) prints n spaces from wherever the cursor happens to be:

PRINT "NAME"; TAB(12); "SCORE"
PRINT "A"; SPC(5); "B"

NAME        SCORE
A     B

OK

TAB is absolute, SPC is relative. When you're laying out a table you almost always want TAB.

POS(0) tells you which column you're on, which is occasionally the only way to work out why something is landing in the wrong place.

A worked example

10 PRINT "ITEM", "PRICE"
20 PRINT "BREAD", 1.2
30 PRINT "MILK", .85
40 PRINT
50 PRINT "TOTAL"; TAB(14); 2.05

RUN
ITEM          PRICE
BREAD          1.2
MILK           .85

TOTAL          2.05

OK

Look at line 30. .85 prints as .85, with no 0 in front — BASIC doesn't add one. And every number is a space further right than the words above it, because of the sign space in front of every number.

Printing numbers as hex

HEX(n) gives you a number in hexadecimal, always four digits with a $:

PRINT HEX(255); " "; HEX(4096)

$00FF $1000

OK

It takes 0 to 65535 and complains outside that. It's the fastest way to make sense of anything you've read with PEEK.

On the screen versus down the wire

Everything above is the same whether you're looking at the ACE's own screen or a terminal on the serial port, with one difference worth knowing: the screen is 40 columns wide and shows the 95 ordinary printable characters. Character codes above 126 don't appear on it at all, so PRINT CHR$(219) puts nothing on the screen even though the character exists in the machine's character set.

Drawing with characters

If you want block graphics on the ACE's screen, build them out of the ordinary printable characters — *, #, ., O and friends. The full character set is reachable from assembly, where you talk to the video chip directly rather than through PRINT.

Next: getting an answer back out of the person at the keyboard.