VIDI VIDEO DIGITISER
VIDI is a video -frame grabber/digitiser specifically designed for
use with the Amstrad CPC range of computers.
With this package, it is possible to capture a picture from any
standard video source, camera, video recorder, even other computers.
You may then save this picture on disc or tape, produce dynamic
effects, manipulate the picture or re–display it on your CPC computer
Pictures can be grabbed in MODE 2 (hi-resolution, 2 shades), MODE 1
(med-resolution, 4 shades) or a special 16 shade MODE O synthesised
VIDI contains its own CRT controller and 16k of video RAM enabling it
to capture a moving picture at over 6 frames per second.
A ribbon cable with dual expansion connectors connects VIDI to the
computer. A suitable video lead is also supplied, fitted with RCA
(phono) and BNC (video) connectors.
Software is provided in two forms, an interactive control program and
BASIC extensions (RSX's) for simple control of the sophisticated VIDI
1. Ensure that the computer is switched OFF.
2. Attach the end of the VIDI ribbon cable to the expansion port of
the computer. See Fig.l, or Fig.2 and Fig.3 opposite.
Care should be taken not - to connect the ribbon cable upside down.
Vidi must be connected-so that the ribbon cable is at the bottom
and the duplicate edge connector is at the top.
3. Connect the phono end of the video cable to the socket on VIDI
and the BNC video plug to the VIDEO OUT* socket on your video
recorder or camera.
4. If your VIDI software is on ROM then insert this into a free
socket in your ROM box as detailed in its instructions.
5. Switch on your video equipment.
6. Switch on your computer and if fitted, the VIDI ROM will announce
Itself. If not insert the Disc or Tape supplied with the package
and Type :-
RUN "VIDI for Disc/Cassette users
or |VIDI for ROM users. < | is obtained by using SHIFT and @ )
7. You should now be watching Digitised pictures on your computer
screen! - if not read the 'Trouble Shooting' section.
TAPE: Side A of the cassette supplied contains the main VIDI command
obtained by typing RUN"VIDI". This is an interactive program
allowing complete yet simple control of the VIDI hardware.
Side B of the cassette contains the seperate commands to allow
you to develop your own BASIC software using the advanced
features of the VIDI hardware.
DISC: The same two main parts of the VIDI software are on disc and
by Typing :-
RUN "DISC, you will be given the following menu:
; 1.. Interactive VIDI command
; 2.. Other RSX commands
To select the correct option, you should press the relevant
key, 1 or 2. Alternatively, instead of RUN"DISC type RUN"VIDI
for the interactive program or RUN"RSX for the seperate RSX
ROM: The ROM software offers all the functions of the |VIDI command
and the RSXs without having to load in' these parts individually.
You will find that using the ROM is much more convenient than
cassette or disc and frees more memory for your own programs (see
appendix A for upgrade details).
Using the |VIDI command
The software supplied with your VIDI video digitiser is contained in
RSX form. The most comprehensive of these RSX commands is IVIDI and
this is the one we shall start with.
At the bottom of your screen there is a MENU, this features a line of
commands, one of which is highlighted (the GRAB option to start with)
by a white bar, or cursor. To move this bar, we can use the left and
right arrow keys on the keyboard or joystick.
If you move the cursor left or right you will see it select in turn
each option. At the edge of the screen it will 'wrap around* and
appear at the other edge.
When an option has been selected, the option values may be changed by
pressing the up and down keys on the keyboard or joystick.
1. The Brightness control
Move the Menu bar to the 'BRGT-07' option. This is the software
brightness control and its range is from O to IS. As this value is
increased or decreased the picture will become brighter or darker
accordingly, with 15 being the brightest.
2. The Contrast control
The contrast control, 'CONT' is operated in much the same way as the
brightness. Increasing the contrast will give a bolder, more defined
picture consisting of less intermediate shades. Similarly, lowering
the contrast results in an increase in intermediate shades and a less
defined picture, just as the contrast on a normal TV.
3. The picture position controls
A normal TV picture is slightly too large to be displayed on tlio
computer screen, instead we look through a window' onto this larger
area. The picture position controls allow us to scroll this window
over the TV picture.
It is possible to adjust the horizontal and vertical positions of the
grabbed picture by changing the values next to the up-down and
left-right arrows. Moving the Menu Bar to the left-right option and
increasing or decreasing its value, will cause the picture to move
slowly across the screen (between 0 and 31 on the control).
The control for the vertical movement is operated in a similar way.
However, beacuse the vertical position control has such a wide range
of values (0-127), when the up or down key is kept pressed, the number
will at first change in steps of one and then in jumps of four for
ease and speed of use.
4. Clearing, selecting, X option and the ESC key.
All control options may be reset to their default values by using the
CLR or DEL keys on the keyboard (the FIRE button on the joystick will
also perform this action).
Many options on the menus do not have values assigned to them, these
options are associated with performing a function or moving to another
menu. To use these other options, you can press any of COPY, SPACE,
RETURN, ENTER or FIRE.
The 'X' option is present in all menus. Its function is to return you
to the last menu or, in the case of the main menu, to BASIC. Upon
selecting the X option from the main menu, the computer will check
that you really want to exit the program. Answer by pressing 'Y' or
FIRE for YES and 'N' or any joystick direction for NO. For
convenience, the 'X' key on the keyboard (X for exit!) or the 'ESC may
be used to exit.
When returning to BASIC using the 'X' option, information such as
inks, mode etc. is restored to the state set before entering the VIDI
program. IThis only applies to the ROM ver sion. )
5. The GRAB menu, X on this menu nill return you to the MAIN menu.
Once you have decided that you are happy with the digitised picture,
select GRAB and a new menu will appear. Notice that the picture has
been 'frozen' - you have now selected that picture and can now do
something with it.
SAVE is used to save the picture to disc or tape.
DUMP will print out a copy of the picture to an Epson compatible
printer using print routines unique to VIDI.
FILE PRINT and controL are documented later.
SWAP will allow you to swap between the picture you selected and the
previous frame - just in case you just missed it!.
6. The FILE menu, X will exit to the CRAB menu.
SAVE does the same as the save option in the GRAB menu, it
is repeated here for convenience.
Filenames must be entered when saving, loading or deleting. When these
options are selected, a prompt and a suggested name will appear. Using
left and right keys, you can position the cursor in the filename and
alter it as required.
The method of inputting is very similar to the BASIC line editor. Left
and right move the cursor (note that the cursor can also move over the
X option, returning you to the GRAB menu) and CONTROL-left and
CONTROL-right move to the start and end of the filename. DEL may be
used to erase characters in the normal way and RETURN, ENTER or FIRE
can be used to indicate that you are happy with the filename. A '?'
may be used as a wildcard within the filename when DELETE is used.
When editing disc filenames, you can also edit the file extension by
typing a dot. This will clear upto the existing extension and allow
you to type in a new one.
LOAD option allows you to load a file to the screen.
If ART option is active a PALette file will also be loaded.
DELETE allows you to delete unwanted files.
CAT will display a catalogue of the disc or tape.
WARNING: using CAT will wipe out the other picture which can be
obtained by using SWAP. In 1 screen mode (see ConTRoL menu) the
picture will be lost entirely and cannot be regained. You have been
BIN is used to change the type of file used.
BIN is the normal screen only format (disc users are permitted to
alter the file extension). The other option ART saves two seperate
files. One is the palette file (with the extension '.PAL')
containing the screen mode and colours, folowed by the screen file
(with the extension '.SCR') which is the normal screen file. This
option is very useful for use in conjunction with 'The Art Studio'
from Rainbird as the palette and screen files are fully compatible,
(note: ART is invalid in Mode 0)
DRV The final entry on the FILE menu is the storage medium.
On a cassette only machine it will be permanently fixed at TAPE but
on a &&4/612B, it will default to DRV-A and can be changed to use
Drive B or Tape.
7. The PRINT menu, X returns to the GRAB menu.
DUMP is the same as dump on the GRAB menu.
Whilst printing, you may press CLR w DEL to terminate the printing.
ESC may be used in emergencies, but due to the way that grapnic
printing works, could lock the printer ON LINE and you may need to
turn it off and on again to reset it.
HORZ allows you to suloct the print direction.
H0RZ will print the screen across the paper, with enough room to
print two screens on one sheet.
VERT prints the picture sideways on the paper producing a larger image
taking up a whole sheet.
1-STRIKE refers to single print density while 2-STRIKE will print
using double density.
A double density dump will produce a bolder image, but take
approximately twice as long to print.
CR+LF Will select between CR ONLY and CR ? LF.
If it is found that there is a gap between every line printed, the
last option on this menu should be changed to CR ONLY instead of
CR+LF, this is to allow for printers that print an automatic line
feed every time a carriage return is received.
8. The ConTRoL Menu, X nill return you to the GRAB menu.
INK option sets the colour assigned to a particular ink.
The first number is the ink number, the second is the colour
number. The up or down cursor will change the number that is
highlighted. The ink numbers cycle from 0 to 15 in Mode 0, 0 to
3 in Mode 1 and 0 to 1 in Mode-2 (different sets of colours are
held for each mode) at the end of each cycle there is also a
feature to change the border colour. If DEL or CLR is pressed
when the cursor is ov«r the colour, that colour will be reset
to its default value. If the same is done over the ink number
then all the colours for that mode are reset. Note that in Mode 1
inks are in the order O, 1, 3, 2 with respect to brightness levels
due to the hardware design.
2-SCR allows you to change the screen update method.
In 2-SCR mode, VIDI uses a technique of grabbing the picture to
memory before displaying it. The 1-SCR option will change this to
make use of only a single screen giving a 'rippling* effect when
grabbing a moving picture, but using less memory.
MODE allows you to alternate between different screen resolutions.
The screen mode may be changed to accommodate Mode 2 (not to be
confused with the 2-SCR option!.). This mode has a higher
resolution but only two colours. When changing the screen mode, a
picture may be displayed in the wrong mode (which can give
strange effects). When you return to the MAIN menu, pictures will
be grabbed correctly in the mode that you have set.
In Mode 0 the screen uill be updated in Node 1 until the picture
is grabbed, when it uill change to Hode 0. tlode 0 is synthesised
by integrating 16 successive frames. This necessitates a still
video source (usually a video earner a).
VW removes the Menu line and view the entire screen.
This is in case the bottom of the picture is incorrect. When
changing the vertical positioning, the end of the grabbed frame
may be visible as a black bar. When VW is selected, the menu will
vanish until you press any key, when it will return.
NOTE: Pressing "V" on the MAIN menu Hill produce the
RESET returns all parameters to their original values. - except
the 1 or 2 screen flip mode.
We have now covered all of the functions contained in the interactive
VIDI software. If you have had difficulty in understanding any of the
functions, read over the appropriate section again and experiment with
the software itself.
THE RSX COMMANDS
As was previously mentioned, the software supplied can also operate
using RSX 'bar' commands from BASIC. However, to write programs
incorporating VIDI, you will need to have some knowledge of the BASIC
programming language of the CPC computers. If you are unsure on
programming techniques, see the example programs on the System disc
supplied and consult your Amstrad User Guides.
All the other external commands can be called directly or from a BASIC
program. Most of the commands have parameters after them separated by
commas, although default parameters are assumed if they are missing.
When using BASIC 1.0 on the 464, it is necessary to pass string
variables to these routines by using a command such as:
whilst, if using BASIC 1.1, you may just type;
Commands are listed with their names and entry conditions. Default
parameters are also listed. So, missing out a parameter in brackets
will use that default value.
Parameters called 'scr* refer to the screens at &4000 or &C000. A
parameter of 0 represents the screen at &C000 and 1 uses the screen at
&4000. If a 6128 is used, or an add-on 64k RamPack then frames can be
grabbed or moved to the banked ram, with these blocks being addressed
as screens 2-5. The default for this value is always ttie current
screen. The commands are as follows s–
|VBANK,scr For 12Bk CPC's. It allows selection of banks 2-5
into the memory location of bank 1 <8.
; All commands (e.g. VGRAB) which write to the current
; screen will update the selected Bank if VS,EE is set
; to scr 1. N.B. The CPC hardware will continue to display
; the original screen (1) if it is selected as the viewing
; screen for example by VSEE,1. However the Firmware will
; write to the new Bank. The viewed screen, therefore,
; remains unchanged.
|VBORDER,n Sets the Border colour to n (0 - 26).
|VIDI(,s) Enter the interactive program. Parameter S
************ should be 1 or 2 to set 1-SCR or 2-SCR modes.
* RON ONLY * Unless using ROM, this command is seperate from
************ all the others due to space limitations.
|VBRI(,n) Sets the brightness to n. Default=7.
; Clears window (left,right,top,bottom) on specified
; screen to current |VPAPER ink. Default is current
; |VWINDOW coordinates and current screen. If only one
; parameter is present it is assumed to be 'scr'. See
; section on WINDOWS for details of specifying
|VC0N(,n) Sets the contrast to n. Default=7
; Swaps inks 2 and 3 on screen (works in mode 1 only).
; This is useful when dealing with other printer or
; graphics routines that need the ink brightness to be in
; the order 0,1,2,3 instead of 0,1,3,2 (the built-in print
; routine will cope with either).
|VCOPY (,sscr (,dscr))
; Copies a screen from source scr, to destination scr.
; If only one parameter is present it is assumed to be the
; source with the current screen as destination.
|VDUMP(,p) Dumps current screen to EPSON compatible printer
; using 27 possible shades for displayed colours. The
; parameter is bit significant:
; Bit=0 (off) ; | Bit=1 (on)
; Bit 0 = CR + LF | CR ONLY ;(add 1)
; Bit 1 = Normal Density | Double Density (add 2)
; Bit 2 = Horizontal | Vertical (add 4)
; If you are unsure of Binary arithmetic, to select the
; functions you want on the right of the table just add
; together the number listed by them.
; e.g. |VDUMP,6 would print a vertical double density
; screen giving carriage returns and line feeds.
; Default=last setting.
|VGET(,scr> Grab a frame to a screen without doing any
setting up. VGET is slightly faster that VGRAD.
|VGRAB( ,scr) Grabs a -frame to a screen, setting up colours,
; made, screen offset (in case screen has been scrolled)
; etc. Note that values for colour and mode are held
; seperate from the normal BASIC values. (See |VMODE
; |VINK etc.)
|VIEW,filename Takes a string parameter and loads and displays a
; palette and screen file. Compatible with Rainbird's
; 'Art Studio'. Only specify the name part when using
; disc – not drive, user or extension.
|VINK(,i(,c)) Sets ink 'i' to colour 'c'for current VMODE. If 'c'
; is missed out, colour will default to its normal
; setting and if no parameters are specified, all inks
; for that mode will be reset.
|VMODE(,m) Sets current grab mode to mode 'm'. Default=1.
; Converts screen into a form suitable for AMX
; PageMaker program. PageMaker has the -facility for
; loading in Mode 0 or Mode 1 screens and converting
; them to its normal Mode 2. However, the inks must be
; in a specific order of brightness, SVPAGE will perform
; this conversion for normal VIDI screens. The screen
; should be saved after |VPAGE by using the BASIC save
; command -e.g.
; 10 LOAD "VIDISCR4.BIN",&C000
; 20 |VPAGE,1,0 ;REM mode 1,screen 0
; 30 SAVE "PAGESCR4",b,&C000,&4000
; Default – current mode and screen. If only one
; parameter is present it is assumed to be 'scr'
|VPAPER(,i) Sets background paper ink for |VCLEAR. Default=0.
|VREAD(,x,y) Reads data from currently defined scan window
; (see SVSCAN) and displays it at screen position x,y.
; (see the WINDOWS section further on for details of the
; x,y coordinate system). The whole scan window is forced
; to lie within the screen boundary. Default=original
; scan window position. If VMODE=0 then no action is
|VRESET Resets all RSX parameters to their default values.
|VSCAN ;Scans a frame into VIDI ram, without displaying it,
; used in conjunction with iVREAD for grabbing and
; displaying windows (see the |VWINDOWS section).
|VSEE,scr Reset screen offset (if scrolled) and view
; screen 0 or 1. Useful for flipping between screens
; after grabbing.
; NOTE: If screen 1 (&4000) is used care must be
; taken not to overnrite any program or data that
; is residing there – possibly causing the computer
; to 'crash'. This can be avoided by setting HIMEM
; to &3FFF (MEMORY &3FFF) before using the
|VSET Set up VIDI values in preparation for grabbing.
; Note: |VSETKVGET is equivalent to '.VGRAB.
|VSMALL,x,y This command has the same restrictions as |VREAD, see
; manual. It will scan a complete screen, compress
; it down to quarter size then display it on the current
; screen, at position x,y.
; Copy a window from one area of the screen to another.
; Parameters are left, right, top, bottom of the source
; window and x, y of the top left corner of the
; destination - all in VIDI coordinates (1,1 to 80,200)
; all must be present. If both screen parameters are
; omitted the current screen is used, if one screen
; parameter is present then it assumed to be the source,
; with the current screen as the destination.
|VWIND0W(,l,r,t,b) Sets a scan window for iVREAD to use. Parameters
; are - left, right, top, bottom. The coordinate
; system used is 1 to 80 for 'x' (columns) left to right
; and 1 to 200 for 'y' (rows) top to bottom. 0 means the
; relevant edge of the screen, i.e.Parameters of 0,0,0,0
; means the whole screen.
; The window defined has a maximum full screen of 80
; columns and 200 lines, where top left = 1,1. bottom
; right = 80,200. When a window is defined, VIDI uses it
; for the IVREAD and SVCLEAR commands. Default=whole
|VXP0S(,n) Sets horizontal frame position. 0-31. Default=16.
|VYP0S(,n) Sets vertical frame position. 0-127. Default=48.
Video signals from different manufacturers equipment vary considerably
and since it is impossible for us at Rombo Productions to test out
every conceivable video source, some fine tuning may be required to
obtain optimum results.
If VIDI is not displaying a picture at all then first check that the
unit has been installed correctly. Check all connections, particularly
the VIDEO OUT on the video. This is almost always directly beside the
VIDEO IN with an identical socket, make sure you have connected the
If your camera/video does not have a BNC type of socket, check that the
VIDEO OUT signal is actually composite video and not RGB or modulated
RF. It ic possible to convert RGD into composite video via a patch lead
— check with your video supplier, however, RF (or TV) modulated signals
are not suitable for VIDI. Some videos are fitted with phono sockets for
VIDEO OUT and in this case you will require a phono/phono cable – available
from hi-fi or video shops. A few videos and televisions are fitted with
a SCART interface (Peritel in France). Suitable composite video is
available from this interface via the correct lead - consult your
VIDI will only grab a frame after the detection of a vertical sync
.pulse within a certain amount of time. Some videos produce erratic
sync pulses on pause and fast search and VIDI may not respond
correctly in this mode.
The aspect ratio of the grabbed picture is controlled by a small blue
adjustable resistor situated near to the edge connector lying flat on
the VIDI board. This is calibrated before depatch, and as this setting
interacts with the software controlled horizontal position it should
only be adjusted with care. This adjustable resistor also controls the
detection of sync signals to a small degree, if your screen looks like
a chessboard when first switched on (with the video attached) turn this
control clockwise until the screen displays the video picture.
All video pictures produce signals of varying strengths. The digital
contrast and brightness controls are initially set by on board variable
resistors. These are the blue square components situated and labelled
next to the VIDEO IN connector. The CONTR. and BRIGHT controls are
calibrated by ROMBO, so before adjusting, the original setting should
be noted. The CONTRAST control is unlikely to be of any use but the
BRIGHTNESS control is useful to give fine adjustments for the software
settings. This is especially so when using Mode 0, as the software
contrast and brightness settings are ignored. Use the external BRIGHTNESS
control to set the overall brightness of Mode 0.
The Amstrad Computer screen has a maximum resolution of 610 horizontal
pixels by 200 vertical lines. An average TV picture has a definition
greater than this, so compromises have to be made somewhere!.
To maintain a correct aspect ratio on the computer screen, the VIDI
frame store is 'windowed'over the TV picture and grabs some 757. of
this picture. However if required clever use of the RSX commands can
enable whole frames to be stored and 'edited'together.
The software Contrast and Brightness controls do not actually modify
the video signal, instead they alter the digital sampling width (contrast)
and level (brightness). Practice may be required to understand their
actual effect on the sampled picture.
The VIDI hardware stores the grabbed frame into its own internal memory,
from where it can be moved to the computers screen or other memory.
In 2-SCR mode, two screens are filled and displayed alternately. These
are located at addresses &C000 (the normal screen) and &4000, each
occupying &4000 bytes(l6K). When using this mode, it is advisable to
set HIMEM in BASIC to be »or less to avoid program or
variables being overwritten.
1-SCR mode will always use the standard screen at &C000 and HIMEM
need not be altered. To enter the program in a specific SCR mode,
use |VIDI,l or |VIDI,2.
We are pleased to help with any technical queries relating to VIDI
and receive suggestions for future enhancements.
Software upgrades and developed applications will be made available
from time to time for a nominal charge (media cost + PI.P). If you
have any routines or programs you would like us to include please
send them to the above address (copyright will be public domain).
ROM SOFTWARE UPDATE
The VIDI software is available on ROM from us direct at a cost of
only £4.95 including VAT and P&P. This ROM will require a ROM box
to be of any use.
The original ROMBO B-Rom box is ideal for use with VIDI. It costs
£34.95 inc. and ordered with the VIDI ROM upgrade the ROM is included
FREE - i.e. £34.95 for both ROMBO + ROM! Please send cheque with
order or any enquiries direct to:
6 Fairbairn Road,
Kirkton North, Livingston,
Scotland EH54 6TS
Tel. 0506 414631
Fax. 0506 414634
PAGE MAKER OVERLAY
There is a file included on the VIDI disc called PAGEMAKE. OVT. This
is an overlay file allowing VIDI to be used within the AMX PageMaker
program. The PA6EMAKE.OVT file should be copied onto your working
copy of the Pagemaker disc by running PAGEMAKE.BAS. The VIDI is
accessed via the 'SCANNER' option within Pagemaker.
AMX PageMaker works in mode 2. The SCANNER option allows VIDI to grab
pictures direct to the screen in mode 2. When you select 'SCANNER'
you will notice a status line appear underneath the command -
; Brightness 8 Vertical 64 Horizontal 22
The brightness refers to the iVBRI parameter in VIDI. It can be
increased by pressing the EXECUTE button. When it goes past IS it
will wrap around to 0.
The keyboard cursor keys are used to control the Vertical
and Horizontal settings. The frame can be positioned so that
any part of the picture is available to any part of the screen
The MOVE button will freeze the current frame whilst pressed.
The CANCEL button will capture the current frame and return to the
If a GRAPHICS WINDOW is currently defined within PageMaker then VIDI
will only grab into the part of the screen lying inside the graphics window.
This feature, for example, allows powerful dynamic displays to be
generated with text and moving pictures on the screen at once!
Pictures requiring better shading than mode 2 should be grabbed and
saved outside of PageMaker using the normal VIDI commands in mode 0 or
1. We have achieved best results with mode 1. After conversion with
the |VPAGE command these can be loaded into PageMaker via the
FILE - SCREENS option. Remember the top of the screen is lost
when loading into PageMaker so frame your picture accordingly.
The BASIC Programs.
Several BASIC programs are included on the VIDI disc as examples
of using the VIDI RSX tfommands.
Me recommend that you load and list these programs to see just
how simple it is to produce apparently complex digitised
The BASIC programs all have a filetype of *.BAS*.
The start of each program listing contains notes on the use
and function of the RSX commands within the program.
This package is Copyright 1986, ROMBO Productions.
All rights reserved. The hardware and software design and composition
of VIDI are copyright. The software may only be copied by the
owner for backup purposes. No part of the software may be
incorporated into other distributed programs without the prior
written consent of the copyright holder. Any digitised pictures
or effects produced with VIDI are NOT subject to this copyright
except for the above conditions.
Hardware design and concepts - Colin Faulkner and Marcus Sharp.
Software design and programs - Keith Wilson
Printer dump routines - Richard Siddons-Corby.
|★ AMSTRAD CPC ★ DOWNLOAD ★|
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L'Amstrad CPC est une machine 8 bits à base d'un Z80 à 4MHz. Le premier de la gamme fut le CPC 464 en 1984, équipé d'un lecteur de cassettes intégré il se plaçait en concurrent du Commodore C64 beaucoup plus compliqué à utiliser et plus cher. Ce fut un réel succès et sorti cette même années le CPC 664 équipé d'un lecteur de disquettes trois pouces intégré. Sa vie fut de courte durée puisqu'en 1985 il fut remplacé par le CPC 6128 qui était plus compact, plus soigné et surtout qui avait 128Ko de RAM au lieu de 64Ko.