The editor

When you switch on ZX-V you are in the editor, where you type and change BASIC programs and give commands. This page explains how it works and what every key does. For the BASIC language itself, see the BASIC course and the reference.

The two screens#

ZX-V shows two different screens:

• The editor screen, the one above: your program listed in 64 columns (or 32, in mode 0), with an empty line at the end for typing new lines and commands. At the bottom there is a status line for messages and a black bar with ZX-V BASIC, the free memory in bytes and the coloured stripes.
• The program screen, where programs run and commands show their results (with PRINT, PLOT and so on), in the program's own mode and colours.

When you run a command or a program, ZX-V switches to the program screen. When it ends, the report (for example 0 OK, 0:1) stays at the bottom of the program screen until you press a key; then you are back in the editor. The key you press is not lost: it counts as typed in the editor, so you can start typing the next line straight away.

Typing a line#

The cursor is a block that blinks cyan and blue. Type as on any computer: letters, digits, symbols (with Shift, as your keyboard shows them) and spaces.

Keywords are typed letter by letter, in upper or lower case: print, Print and PRINT are the same. When the line is stored, ZX-V shows it again with the keywords in capitals and its own spacing: typing 10 goto 20 gives 10 GO TO 20. Variable names keep the case you typed.

A keyword must not run into the letters or digits that follow it: GO TO 20 and PRINT"hi" are fine, but GOTO20 is not read as GO TO 20. When in doubt, leave a space.

You can type the characters with codes 32 to 127 (including £ and ©, if your keyboard has them). Letters with an accent, a diaeresis, a tilde or a cedilla are typed without it (é becomes e, ñ becomes n, ç becomes c), and ¿ and ¡ become ? and !; other characters do nothing. Block graphics and user-defined graphics are written with CHR$ (see the character set). A line can be up to 1024 characters long; long lines continue on the next rows of the screen.

If you know the Spectrum: the editor works like the one of the +2/128K: you edit the listing in place, there are no K, L and E modes, and the EDIT key opens the options menu. The keys are those of a PC keyboard, without CAPS SHIFT and SYMBOL SHIFT.

Program lines and direct commands#

What happens when you press Enter depends on how the line starts:

• With a number (from 1 to 9999), it is a program line: it is stored in the program, in its place by number, and nothing runs yet. If a line with that number already existed, it is replaced.
• Without a number, it is a direct command: it runs at once, on the program screen. For example PRINT 2+2, RUN, SAVE "game" or CLS.

Before storing or running anything, ZX-V checks the line. If there is a mistake, you hear a short buzz, the cursor jumps to where the problem is and the status line shows what is wrong in red (usually C Nonsense in BASIC). Nothing is stored or run until you fix it, as in the picture at the top of this page.

After storing a line, the cursor goes to the start of the next line of the listing, or to the empty line at the end.

Moving around and changing lines#

The whole listing can be edited in place: move the cursor to a line, change it, and press Enter.

Some useful things:

• Leaving a changed line stores it. If you change a line and move to another one with the cursor keys, the line is stored as if you had pressed Enter. If it has a mistake, the cursor stays on it until you fix it or press Esc.
• To undo the changes to the line you are on, press Esc: the line goes back to how it was.
• To delete a line, type its number alone on the empty line and press Enter (30 deletes line 30). To delete several, use DELETE.
• To copy a line, change its number: the line is stored with the new number and the old one stays where it was.
• To run a line as a command, delete its number and press Enter: the text runs as a direct command, and the program line stays as it was.
• Pressing Enter on a line you have not changed just moves to the next line.

The empty line at the end keeps what you type even if you move up to look at the listing and come back.

The listing indents itself: whatever is inside a FOR, WHILE, REPEAT, DEF PROC, SELECT CASE or a block IF shows two spaces further right for each level, and ELSE and CASE one level less. The spaces are not stored (they take no memory), so there is no need to type them: when the line is stored, the editor indents it. LIST and the .bas files written by SAVE look the same.

Running a program#

• RUN runs the program from the start (it first deletes the variables); RUN 100 runs it from line 100. GO TO 100 also runs it from line 100, keeping the variables.
• Press BREAK (the Esc key) to stop a program. The report is L BREAK into program, and CONTINUE carries on from where it stopped.
• When a program fills the screen, it stops and asks scroll?: any key goes on, and N, Space or Esc stop it.
• The report at the bottom says how the program ended and where (see Reports): 0 OK, 70:1 means it ended normally, at statement 1 of line 70.

Finding a line: LIST and EDIT#

In a long program, Page Up and Page Down go ten lines at a time, and Ctrl+Home and Ctrl+End take you to the start and the end. To go straight to a line, type one of these as a command:

• LIST 200 puts the cursor on line 200 (or the next one that exists), ready to edit it. LIST alone goes to the start.
• EDIT 200 does the same; EDIT alone goes to the last line you stored.

To see the listing on the program screen instead, as on the Spectrum, use LIST #2. LLIST sends it to the printer file.

Numbering lines: AUTO, RENUM, DELETE#

• AUTO gives you line numbers automatically: after AUTO, the empty line already starts with the next number (the last line plus 10), and each time you press Enter the next number appears. AUTO 100, 5 starts at 100 and goes up in fives. It ends when you press Enter on a line with only the number, press Esc, or move to another line.
• RENUM renumbers the whole program in tens (or RENUM 1000, 5, from 1000 in fives), and corrects the numbers after GO TO, GO SUB, RESTORE, RUN, LIST, LLIST and LINE. Line numbers worked out by the program, as in GO TO n*10, are not corrected; labels (@name) never need it.
• DELETE 100, 190 deletes lines 100 to 190.

These three work only as direct commands.

Blocks of lines#

To copy, move or delete several lines at once, mark them first:

1. Put the cursor on the first line and press Shift+↓ (or Shift+↑ to go upwards). That line and the next are marked, and each time you press it again one more line is marked. Marked lines show in yellow.
2. Move the cursor to where you want the block and press EDIT (Tab). With a block marked, the menu has three more options:

The copied or moved lines get numbers between the cursor line and the next one, in tens if they fit (closer together if not). If there are not enough free numbers for all of them, the program is first renumbered in tens, as with RENUM. When copying, the line numbers inside the copied lines do not change: they still point to the same lines as before.

To delete the block, put the cursor on one of its lines and press Delete: the status line asks Delete 3 lines? (Y/N), and only Y deletes them. Esc unmarks the block without doing anything.

Find and replace: FIND and REPLACE#

• FIND "text" moves the cursor to the next program line where the text appears, starting with the line after the cursor and going round to the start at the end. The cursor lands right on the text. Upper and lower case are the same: FIND "print" finds the PRINTs.
• F3 finds the same text again, from the cursor. So does FIND on its own.
• REPLACE "old", "new" changes the text in the whole program. Each changed line is checked as if you had typed it: if it would have a mistake, it is left alone. The status line says how many changes were made (5 changes), and in red how many lines were left unchanged.

Both search the listing as you see it, keywords, quoted text and REMs included, but not the line numbers.

Undo#

The Undo option in the EDIT menu undoes the last change to the program: a line stored or deleted, a block copied, moved or deleted, and also REPLACE, RENUM, DELETE, NEW, LOAD and MERGE. Used again, it redoes what it undid. If the cursor line is half changed, it first just puts it back as it was, like Esc.

To be able to undo, the editor keeps a copy of the program in free memory, without taking it from anyone. If a program later needs that memory (with a large DIM, for example), the copy is lost and the status line says Nothing to undo. With a very large program, which leaves no room for the copy, undo is not possible either.

The options menu (EDIT)#

Press EDIT (the Tab key) to open the options menu in the middle of the screen:

Choose with ↑ and ↓ and press Enter. Esc or Tab close the menu without doing anything.

Renumber and Print work with the stored program: if the line you are on has been changed, it is stored first (and if it has a mistake, the menu closes so that you can fix it).

The editor in mode 0#

The editor starts in screen mode 1: 64 columns and 46 rows for the listing, in small letters. The Mode 0 option in the EDIT menu switches it to mode 0, like the 128K's: 32 columns and 22 rows, with letters twice as big, easier to read on a TV or from a distance. Long lines carry on in the rows below, as in mode 1, and the bar at the bottom only shows the free memory (without "bytes free"). In mode 0 the same option is called Mode 1 and puts it back as it was.

The editor's mode has nothing to do with your programs' (MODE): each one uses its own screen. It stays after NEW, and when the machine is reset the editor goes back to mode 1.

The status line#

The line just above the bar shows:

The message disappears with the next key you press. The bar under it always shows the free memory: the program and its variables share about 94 KB.

Saving and loading#

Programs are kept on the SD card. From the editor:

• SAVE "game" saves the program as game.zvb. SAVE "game" LINE 10 saves it so that it runs by itself from line 10 when loaded.
• LOAD "game" loads it, replacing the program in memory.
• CAT lists the files of the current folder, and CAT "ROM:" the examples that come with ZX-V; LOAD "ROM:hello" runs one of them.
• MERGE "game" adds the lines (and the variables) of a saved program to the one you have.
• OPEN #4, "game.txt" OUT: LIST #4: CLOSE #4 writes the listing as a text file, to read it on a computer.

NEW deletes the program, and loading a native program (.zxv) also clears BASIC when it ends: save your work first. All the details are in the reference, under Files and the SD card.

The language of the editor#

The bar, the menu, the messages and the error reports are in English or Spanish, the language of the machine. Change it with LANGUAGE "es" or LANGUAGE "en" (see LANGUAGE); the emulator also has an option for it (see the emulator).