Mode 7 Screen Displayer

This allows you to display screens saved in the right format (by either KeySaver or Converter) and print them as MODE2 screen files.

When you first run the program, the disk drive will whirr for a short time and then you will be asked to:

      Enter file to display:

This is the filename of the screen you want to display as you originally saved it on the disk. The program will then pause for a while for calculation and the next part of the program will load. The prompt:

      Print or Save Screen (P/S)

will appear and you must press P or S according to what you want to do. The screen will be saved under the filename SCR so if you have a file of this name on your disk already you should rename it or it will be overwritten. The screen will then go blank for above five minutes while the program converts the MODE 7 screen to MODE 2. If you are using a Turbo Driver you can see the screen being built up. After the screen has been converted, the display will return and the screen will be saved or printed according to the choice you made earlier (ensure the printer is on line and fed with paper). The screen has now been converted and if saved can be loaded in again by entering MODE 2 and typing:

      *L. SCR

A sample screen is supplied called "CrazySc".

Converter

This utility is designed to convert a screen saved on a BBC as a screen file in MODE 7 to a format understandable by the Displayer.

When you load the program from the menu the prompts:

      Enter filename to load:
      Enter filename to save:

will appear in succession. For this, enter the name of the screen file and the name you want the file to be saved under. Next you should press a key to initiate loading. There will be a short pause while calculations are made and then the disk drive will whirr for about a minute and the screen file will be loaded and converted. You should then press a key to begin saving the screen.

KeySaver

This utility allows screens to be saved in a form understandable by Displayer from within the program that generates them.

When you run the program, you will be prompted for a filename to save the screen under. Then there will be a short pause and you will be returned to control of the computer. The characters will appear as a "mushy" pattern but this is essential to the program, and if BREAK is pressed or the characters altered, the routine is rendered ineffective. You should still be able to see when the screen you want is shown and press CTRL to save it to disk under the filename you chose earlier.

ElkFax

This is a message display system based on the routines used in the Mode 7 Screen Displayer. It allows a sequence of screens to be created and displayed from disk, rather like a ViewData or teletext system. Using the built-in editor you can define well over 100 pages of text and graphics in 16 colours (8 still, 8 flashing). Then using the display routine you can show the pages in sequence or choose a page directly to display. There are a dozen uses for this system e.g. shop window advertising, information services, school "electronic magazine", etc.

The graphics are characters on a 2 x 2 matrix. They seem rather chunky and crude, but a glance at teletext will show how effective the results can be.

Load the program and you will be asked for the name of an ElkFax file. Enter the filename and insert the disk with the file on for editing to display. If there is no file of that name on the disk one will be created with blank pages. If a file is to be created, the program will warn you by giving a message saying how much space is needed on the disk for the file. Insert a disk with enough space and press a key. It is advisable to use blank disks for creating new files on to make sure there is enough room.

After this you will be asked whether you want to edit or display the file. Press E to edit or D to display.

Editing

The first page (0) will be loaded ready for you. Your controls are detailed below:

C	Change foreground colour
B	Change background colour
T	Input text
S	Save page
L	Load page
RETURN	Move cursor down to start of next line
Cursor keys	Move cursor around the screen. The flashing block shows where the next character you place on the screen will appear.

To input text, tap T and enter your text. Take care to enter one line of text only.

The current page is shown at the top left of the screen, and the current colour at the top right (left hand digit=foreground; right hand digit=background). A list of colours is shown below:

0 -	black	8 -	flashing black/white
1 -	red	9 -	flashing red/cyan
2 -	green	A -	flashing green/magenta
3 -	yellow	B -	flashing yellow/blue
4 -	blue	C -	flashing blue/yellow
5 -	magenta	D -	flashing magenta/green
6 -	cyan	E -	flashing cyan/red
7 -	white	F -	flashing white/black

When saving a page, you will be asked for the page number. This allows the same page to be copied to several different numbers and each copy altered separately. This is sueful if each page requires a particular graphic heading at the top.

Displaying

When displaying an ElkFax file, you will be asked for start and end pages. Enter these and press RETURN. You will also be asked if you want to display the pages in a carousel. This means that the pages will automatically step through in sequence (e.g. in a window display). Once the display is going, you can type a page number to go to, or press any other key to step to the next page. If the carousel option is on, the page will move to the next one after a certain length of time (about 30 seconds) has passed.

A sample file (filename faxE) is supplied which allows you to get an idea of what ElkFax can do. To see it, load ElkFax and press D for display. Enter the first page as 0, the last as 3 and Y to the Carousel? prompt.

Mode 7 Emulator

This program, for 64k Electrons only, allows MODE 7 displays to be shown in real time on an Electron. It will work with most correctly written BASIC or machine code programs and provides a complete emulation of all standard teletext control codes. Fantabulous!

Gareth Boden, EUG #23

HeadFirst PD