HomeSoftwareArchiveTop TipsGlossaryOther Stuff







Camcorders and computers make uneasy bedfellows but increasingly the two technologies are being combined, as these three new products demonstrate



Until recently camcorders and personal computers have had little in common, but gradually the two technologies are coming together in what is turning out to be a very fruitful partnership. Computers have much to offer the video movie-maker, and most recently attention has focused on their ability to generate high-quality text and graphics, which can be used in home video productions in a variety of ways, from titling to special effects.


Unfortunately many computers have great difficulty in communicating with video equipment, though there are honourable exceptions, including a number of home computers such as the Commodore Amiga, Atari ST and Sinclair Spectrum, all of which have PAL compatible video outputs. These models -- especially the Amiga -- have established a sizeable following amongst home movie-makers users. More recently interest has turned towards the dominant business and commercial computer systems -- IBM PC/PC compatibles and Apple Macintosh -- which are now making significant inroads into the home computer market. This follows a dramatic fall in prices over the past three years and now extremely powerful desktop computers, supported by a wealth of widely-available and easy to use software, need cost no more than fairly basic (by comparison) home computers.


When these systems were designed there was thought to be no need for them to be able to interface with video equipment, so their visual displays have evolved along quite different paths to domestic TV. This has made it difficult to convert their video outputs to PAL, and even harder to mix computer graphics with PAL (or NTSC) video signals. It has been estimated that there are around 60 million PCs and clones in use around the world, so it should come as no surprise to learn that the technical hurdles have been quickly overcome in order to tap this highly lucrative market.


The first signs that the IBM PC had a future in video production was in 1991, following the launch of a number of professional PC-based editing systems that utilise the PC's formidable control and storage abilities, domestic versions quickly followed, none of them involved any video processing.  More recently a number of video output converters have appeared on the market, that enable the computer's video output to viewed and recorded on domestic TV and video equipment, in turn these have spawned a variety of title and presentation software packages. However, the holy grail of computer post production is the genlock, a device which allows the computers video output to be mixed or overlaid with an external video signal, usually from a camcorder or VCR. Genlocks for PC (and Apple Macs) are themselves small computers, such is the complexity of the conversion and mixing process, which is one of the reasons why they have been such a long time coming, and until now, very expensive, but that is all about to change with the arrival of a new generation of PC and Mac compatible converters and genlocks.  We've been looking at three of them, and the signs are they're just a taste of what is to come!




The G-Lock is aimed at the top end of the market, and that is reflected in the selling price which with VAT comes to well over 1,000! That's getting on for twice the price of some of the computers it's designed to be used with, so it should be something special. And so it is, G-Lock fits inside the computer, replacing the existing VGA (video graphics array) display card.


G-Lock can be used with any IBM PC AT computer with at least 640k bytes of memory, running MS-DOS 3.1 or above. It works best with a multi-sync monitor, normal VGA monitors will not work as they are incapable of locking onto the re-configured display, in which case you will have to rely on the TV monitor screen to operate the system; it can be done but it makes life much easier if you can use the computer's own screen.


It's a DIY installation and requires no specialist tools or knowledge, the accompanying manual  contains fairly detailed fitting instructions but if you're at all worried any competent computer buff should be able to do it for you in a few minutes.


The computer's monitor connects to the board in the normal way, and there are two additional mini-DIN S-Video sockets for the video input and output. A pair of S-Video to phono leads are supplied for composite video signals. The only external adjustment is a switch for setting S-Video or composite video mode. To get the board up and running it is necessary to load in some software utilities, this takes just a few minutes, though be warned the manual assumes a certain amount of familiarity with DOS commands, and some of the more advanced operations, such as setting up and modifying AUTOEXEC. BAT and SYSTEM. INI  files require some specialist knowledge. 


Our sample worked well, though once or twice the computer failed to boot correctly. This was apparently caused by the G-Lock card as the problem disappeared as soon as the original card was replaced. Switching the machine off and on again always cured the problem and it never glitched once when it was operating.  There are several display options, (including pre-loaded graphics and test patterns) with standard graphic and video mixing, and colour-keying, where a designated colour in the computer generated graphic is replaced by genlocked video. The latter has enormous potential for special effects and titling, and with patience, a little creativity and good titling software the results can be to professional standards.  



Make/model                GVP G-LOCK VGA+

Guide Price                  1173

System                         SVGA graphics card and genlock

System compatibility   IBM PC AT and compatibles (286 or higher)

Video in/out                  S-Video (S-Video to phono conv. leads supplied), VGA out

Features                       fade and mix, key and transparent colours, flicker stabilisation,

software utilities and drivers inc. Windows, Lotus 123, WordPerfect; graphics and  test patterns  

Dimensions                  full-size expansion card, (16-bit ISA bus), replaces existing VGA card

Distributor                   SILICA SHOP  1-4 The Mews, Hatherley Road,

Sidcup, Kent DA14 4DX. Telephone 081-309 1111



Top-end PC genlock for serious users




Genlocks are the only way to go if you want to mix video and graphics together but if you just want to be able to view or record graphics from your PC on a normal TV or VCR then the VGA-TV Buster from Rombo might be just what you're looking for. Depending on the software used it can be used for titling on home video recordings, or to create displays and presentations which can be shown on TVs or projectors.


VGA-TV Buster is available as a stand-alone unit, or an internal fitting card, which plugs into one of the computer's expansion sockets, we've been looking at the internal version. It's comparatively easy to fit, thought the instructions are misleadingly worded about the fitting of a flying lead, which plugs into the machine's monitor socket. Driver software and utilities for Buster, as we'll call it from now on, are supplied on a 3.5-inch disk and has to be installed from a DOS prompt; some knowledge of the workings of a PC is an advantage. Users will also need to know which type of VGA adaptor their machine has, in order to configure the unit, but the instruction book is fairly easy to follow from this point onwards, and there's a technical support line for anyone who gets into difficulties.


Buster can be installed as a Windows accessory, so it can be switched in and out very easily, this enables the composite/S-video output, so it can be viewed on a PAL TV, when this happens the normal VGA monitors looses lock and displays a confused image.


The output image can be moved around the TV screen area using cursor keys or mouse control (from a Windows installation); it is reasonably stable, and there are some adjustments to minimise colour smearing and patterning. On the whole, though, Buster works well, it's fairly basic but it is realistically priced and adds another new string to the PC's bow, making it a whole lot friendlier towards domestic video.  



Make/model                 Rombo VGA-TV Buster          

Guide Price                              175.07

System                                     internal VGA-PAL (composite or S-Video) converter

System compatibility              IBM PC or compatible

Video in/out                            composite, S-Video and RGB output

Features                                 positionable graphic display

Dimensions                            expansion card

Distributor                                         Rombo Productions Ltd., Baird Road, Kirkton Campus, Livingston, EH54 7AZ. Telephone (0506) 414631.



Video versatility for the PC




This simple, no-nonsense external genlock is the first budget model we've seen that is  compatible with a range of computers, including IBM PC, Apple Mac and Archimedes. At just 299 (plus VAT) it represents excellent value for money. Features include mix computer graphics to black or external video input, and an underscan/overscan option which ensures the edges of the computer display are not lost on the video output.


Installation is fast and simple, Multigen is supplied with a PC compatible lead which plugs into the computer's monitor output socket;  the displaced monitor lead plugs into a socket on the back of the Multigen, various lead options are available for other makes of PC, and a lead for the Apple Mac, for example, costs an extra 8.80. Video input and output are handled by two phono and two S-Video sockets, there is also an RGB monitor output. In this arrangement the computer monitor operates normally,  the genlocked display is only visible on the composite and S-Video outputs.


There are few preliminaries, just connect it up to its (optional) external mains power supply, check the positions of the DIP switches on the back panel, (these select the video system and fade speed). Once it is operating it may be necessary to adjust the display key level or transparency, there is a small preset control on the back panel. The front-panel controls are equally simple and to the point; push buttons select over or underscan modes, source signal format (composite or S-Video) , operating mode (overlay or mix ), fade, and freeze (computer graphic).


Multigen supports all of the standard resolutions, up to 640 x 480 pixels/256,000 colours, so the quality of output is quite good, some instability is evident, despite the use of flicker reduction circuitry, though much depends on the design, position and colour of the graphics and in some circumstances it is hardly noticeable. The video signal appears to pass cleanly through the unit, with no perceptible increase in noise or loss of resolution.


We have just a couple of quibbles, the power supply is sold as an optional extra, Vine say this is because many of their customers already have mains adaptors and will want to use their own, that's a recipe for trouble as the only reference to the units power requirements are on a small sticky label on the polystyrene packaging. The second concerns the additional cost for Mac users, who will have to pay an extra 8.00 for a lead, the PC lead is supplied as standard.


Multigen is simply a means to an end and the end results will ultimately depend on the scope of the graphics software used. Vine recommend the PC Titler program from Maze, which they can also supply, they are still evaluating suitable software for the Mac.

The Multigen is what PC owners have been waiting for, a good quality, fuss-free genlock at a sensible price. Recommended.




Make/model                Vine Multigen

Guide Price                  358 (Apple Mac lead 8.80)

System                         External genlock

System compatibility   IBM PC, Apple Mac, Atari ST, Archimedes

Video in/out                  PAL/NTSC, S-Video, composite video, RGB out

Features                       under/over scan, variable-speed fade, mix, freeze, flicker stabilisation

Dimensions                  150 x 45 x 94mm

Distributor                    Vine Micros Ltd., Vine House, Cowper Road, Margate, Kent CT9 1SX. Telephone (0843) 225741



The one to beat!



R.Maybury 1993 2807






[Home][Software][Archive][Top Tips][Glossary][Other Stuff]

Copyright (c) 2005 Rick Maybury Ltd.