Editing Sinclair BASIC (section)

==Notes==
{{reflist|30em|group="note"|refs=
<ref group="note" name="logical">"False" in Sinclair BASIC equates to 0 (zero), everything else equates to "true". Functions that return true-or-false values thus actually return 0 for false and 1 for true, while <code>AND</code> usually returns the first of the conditions supplied for true, or 1 if no numerical values were given. For example, <code>6 AND 7</code> returns 6, while <code>NOT 6=7</code> returns 1.</ref>

<ref group="note" name="microdrivecommands"><code>CAT</code>, <code>ERASE</code>, <code>FORMAT</code> and <code>MOVE</code> were originally designed to be used with peripherals, but at the launch of ZX Spectrum, they had not been completely implemented, such that their use generated an error message (Invalid Stream). Later with the aid of the ZX Interface 1 shadow ROM, they were used for the [[ZX Microdrive]]. (The shadow ROM was paged when the BASIC interpreter detected a syntax error, which is why most ZX Microdrive commands use a <code>"*"</code>).</ref>

<ref group="note" name="if-else">Unlike many other BASIC dialects, Sinclair Basic did not include the <code>ELSE</code> operator in the <code>IF</code>–<code>THEN</code>[–<code>ELSE</code>] clause. A workaround would be to use an <code>IF</code>–<code>THEN</code>–<code>GO&nbsp;TO</code> construct instead, bypassing the lines that would have been in an <code>ELSE</code> clause with the <code>GO&nbsp;TO</code></ref>

<ref group="note" name="colournumbers">The available numbers for colours are:
{| class="wikitable" 
| 1 || 2 || 3 || 4 || 5 || 6 || 7 || 0
|-
| style="font-weight:bold;background-color:#000000;" | {{font color|blue|blue}} || style="font-weight:bold;background-color:#000000;" | {{font color|red|red}} || style="font-weight:bold;background-color:#000000;" | {{font color|magenta|magenta}} || style="font-weight:bold;background-color:#000000;" | {{font color|green|green}} || style="font-weight:bold;background-color:#000000;" | {{font color|cyan|cyan}} || style="font-weight:bold;background-color:#000000;" | {{font color|yellow|yellow}} || style="font-weight:bold;background-color:#000000;" | {{font color|white|white}} ||  style="font-weight:bold;background-color:#ffffff;" | {{font color|black|black}}
|}
In all colour-related commands, the number 8 may be used to indicate "transparent" while in <code>INK</code> and <code>PAPER</code> may also be set to 9 for "contrast" – that is, to put a dark colour on a light background or vice versa automatically.</ref>

<ref group="note" name="colours"><code>INK</code>, <code>PAPER</code>, <code>FLASH</code>, <code>BRIGHT</code>, <code>OVER</code> and <code>INVERSE</code> set attributes for outputting text and graphics to the screen.  They can be used either as commands, to apply to all subsequent output until set again, or within a <code>PRINT</code> statement, to apply only from that point until the end of the statement.</ref>
}}