mrg@ihlpm.ATT.COM (M R Gales) (05/02/87)
I am in the process of making a purchasing decision on either an Atari Mega ST (when available) or a Comodore Amiga Computer. One of the desired uses of my new computer is to use it to create video titles that I can record onto video tape when I edit home videos of vacations, etc. The Amiga has composite color video out, which is what I need for this application. The Atari 1040ST and the Mega ST (as far as I understand) does not. Does anyone know of a way, or better yet know of anyone who sells a box that I can purchase for the Atari that can convert its RGB output to composite video? I appreciate any info you can give to me. If I can come up with a box to do this, this will help sway me to an Atari, otherwise, I will have to choose an Amiga. Are there any other strong reasons why I should buy an Atari? I am a novice to personal computers, so any info will help my decisionww
bryce@COGSCI.BERKELEY.EDU (]} ae]]]}]]]}) (05/02/87)
In article <1102@ihlpm.ATT.COM> mrg@ihlpm.ATT.COM (M R Gales) writes: >I am in the process of making a purchasing decision on either an Atari Mega ST >(when available) or a Commodore Amiga Computer. One of the desired uses of my >new computer is to use it to create video titles that I can record onto video >tape when I edit home videos of vacations, etc. The Amiga has composite color >video out, which is what I need for this application. >[Is there anything I can buy to convert Atari RGB to composite?] There are several much more important things to think about in chosing a computer for video work: WARNING: WHAT FOLLOWS ARE FACTS. NO FLAMES!! 1> Overscan: Normal TV pictures 'flow' past the edge of the picture tube. Computer displays like the ST will usually consist of a 640*200 pixel active area in the center of the screen. On the ST this comes with 4 colors per scan line. Other computers, among them the Amiga, allow 'overscan'. Nominal resolution on the Amiga is 640*200. Maximum is 752*484 with 16 colors per scan line. With overscan the picture can fill the full screen, like a normal broadcast picture does. 2> Interlace: NTSC video is interlaced. This includes broadcast TV and video tape. Some video gear may REQUIRE a interlaced picture to function properly. Consumer gear will not care. For your purpose it will mean twice the number of lines of resolution, and a easier time if you go beyond simple titling. The Atari computers do not directly support interlaced video. The Amiga supports interlace. 3> Fancy stuff that (unfortunately) only the Amiga has. This includes genlocking inputs so that the Amiga can sync to an external source (for overlays etc.). Other fancy tricks like 'chroma key' will only be easy on an Amiga. 4> [more stuff not included 'cause I'm sick of typing] The Amiga was designed with FULL NTSC COMPATIBILITY AS A PRIMARY GOAL. For example the internal clock frequency is a multiple of a primary NTSC video frequency, colorburst. Careful attention was paid to the format of the video output. etc... The Atari ST was designed with other criteria in mind. ****************************************************************************** NO OTHER COMMENTS ARE EXPRESSED OR IMPLIED AS TO DIFFERENCES BETWEEN MACHINES. ****************************************************************************** In answer to the actual question asked: Yes RGB to composite converters are made. I do not have any details on where and how. These could be adapted with a minimum of soldering to fit on a Mega St. It is possible to create interlaced video from non, but you will never get the 2 times increase in resolution unless you start with it. ---------------------------------------------------------------------------- "The future is not what it used to be." ---------------------------------------------------------------------------- Disclaimer: I don't work for Atari, nor Apple or Commodore not IBM, sun, intel... in fact ?just what is it that I DO DO? [ do-do? :-) ] ----------------------------------------------------------------------------
pete@utgpu.UUCP (05/04/87)
In article <8705021243.AA24169@cogsci.berkeley.edu> /dev/nul.nil.nul.the.bit-bucket.@cogsci.berkeley.edu writes: >In article <1102@ihlpm.ATT.COM> mrg@ihlpm.ATT.COM (M R Gales) writes: >WARNING: WHAT FOLLOWS ARE FACTS. NO FLAMES!! Arn't we sure of ourselves!!! >3> Fancy stuff that (unfortunately) only the Amiga has. This includes > genlocking inputs so that the Amiga can sync to an external source (for > overlays etc.). Hate to put a damper on your amiga worshiping, but the ST DOES allow FULL EXTERNAL SYNC. This feature was included specificallyu for this kind of work. Only facts eh? >In answer to the actual question asked: Yes RGB to composite converters are >made. I do not have any details on where and how. These could be adapted >with a minimum of soldering to fit on a Mega St. Also, if you are at all handy with a soldering Iron, a very good simple interface design is available in the Public Domain from Anees Munshi at U of T. Also, I have heard that several German companies are offering exactly the interface you desire. Pete pete@utgpu
cmcmanis@sun.uucp (Chuck McManis) (05/04/87)
In another article, (Peter Santangeli) responds to : > An article Bryce Nesbitt wrote, which said : >> 3> Fancy stuff that (unfortunately) only the Amiga has. This includes >> genlocking inputs so that the Amiga can sync to an external source (for >> overlays etc.). > Hate to put a damper on your amiga worshiping, but the ST DOES > allow FULL EXTERNAL SYNC. This feature was included specificallyu > for this kind of work. Only facts eh? This is news to me, and I have kept a fairly close watch on the two computers. My question is this, are these external syncs available at one of the video connectors ? Or do I have to run wires into the box somewhere ? >>In answer to the actual question asked: Yes RGB to composite converters are >>made. I do not have any details on where and how. These could be adapted >>with a minimum of soldering to fit on a Mega St. > Also, if you are at all handy with a soldering Iron, a very good > simple interface design is available in the Public Domain from Anees > Munshi at U of T. Also, I have heard that several German companies > are offering exactly the interface you desire. > Pete Correct, I have seen the composite video circuit described above. The unique ability of the Amiga is/was (whatever) Genlock. This means the Amiga can sync to an external video signal and mix it's graphics with the video of the external source. What is required for this capability is external sync for the Amiga graphics and a 'smart' switch that knows to use external video when the Amiga is 'displaying' color 0. And then to take this mixed video and produce a composite out to be recorded on the tape deck. Note that it is possible to do chroma-key type stuff externally where an external mixer looks for a given hue and replaces it with video from a separate source, thats how they do the weather maps on tv, by replacing everything 'blue' in the picture with the weather map. (It is really interesting if the weatherman is wearing a blue tie!) Now on the Amiga, since the hardware is 'expecting' a GenLock interface it has some hooks built in for that. Consequently the GenLock add on is relativly inexpensive, its biggest job is to convert composite video to RGB so that it can be displayed on the Amiga screen and the user can see what the output will look like. List price for a Genlock interface is $299. To do chroma keying requres a video mixer with chroma key as an option. I believe Recoton sells one of these for $1800. If the Atari cannot be sync'd to NTSC sync timings you will also need a timebase corrector which goes for about $800. This will be essential if you wish to use the Atari High resolution monochrome mode. Now given the context of this *single* application, one can say the Amiga is better for *Video Titling* than the Atari ST. And if I may be so bold as to say that this is the *only* way to compare systems. Is it better for *your* particular application. Anyway I look forward for specifics to how the Atari External sync is used. -- --Chuck McManis uucp: {anywhere}!sun!cmcmanis BIX: cmcmanis ARPAnet: cmcmanis@sun.com These views are my own and no one elses. They could be yours too, just call MrgCop() and then ReThinkDisplay()!
bryce@COGSCI.BERKELEY.EDU.UUCP (05/06/87)
In article <> pete@gpu.utcs.UUCP (Peter Santangeli) writes: > >>WARNING: WHAT FOLLOWS ARE FACTS. NO FLAMES!! >Arn't we sure of ourselves!!! >>3> Fancy stuff that (unfortunately) only the Amiga has. This includes >> genlocking inputs so that the Amiga can sync to an external source (for >> overlays etc.). > >Hate to put a damper on your amiga worshiping, but the ST DOES >allow FULL EXTERNAL SYNC. This feature was included specificallyu >for this kind of work. Only facts eh? > Uhhh sorry. Consider those words eaten until I get a third opinion. I was using a faulty source -> the technical info sent by Atari to developers <- darn unreadable photocopies! The newer stuff may have this correct, BUT NOBODY TOLD ME! And who says I worship Amigas? You may, however, replace "genlocking" with Hold And Modify, copperlists, pre-analog RGB (12 digital bits-A2000 only) etc, etc... -Me- PS. I *do*, however, worship toasters, washer/dryer sets and other major appliances. 8-)
pes@ux63.bath.ac.uk (Paul Smee) (05/06/87)
Genlock for the ST was shown (working!) at the recent show in London. In particular, it was being demoed for titling 'proper' video. Also, a real-time digitizer box.
pes@ux63.bath.ac.uk (Paul Smee) (05/06/87)
Also, (it occurs to me, and I'm probably on shaky ground since I'm making a guess generalization about the US ST's handling of NTSC from the foundation of the UK ST's handling of PAL) I expect you'll find that the Atari uses normal bog-standard interlaced scan when it thinks it is talking to a colour monitor; believe it is only the mono monitor which uses non-interlaced scanning (and a truly obscure non-standard scan frequency into the bargain). However, since I've mentioned it, can someone who *really* knows for sure let me know whether this surmise is correct? Anyone from Atari listening?
cabbie@chinet.UUCP (Richard Andrews) (05/07/87)
I did some genlock work on the 520/1040 ST machines and have discovered the following. When in external sync mode the 520/1040 does not produce hsync-subcarrier locked video. This causes a color banding effect on the screen. Depending on the version of GLUE the screen display may be either jumpy, 1/2 black, or 3/4 black when in the extrenal sync mode. The h-sync is missing equalization pulses, hence, no NTSC standard output. The composite output of the ST stinks. There is no delay line in the RGB to composite coverter (modulator) which causes this. There are other problems but they can be elimated quite easily. In short, unless Atari re-works GLUE or the system clock or both there can be no genlock. Richard Andrews Asst. Chief Engineer WCFC-TV Chicago -- ******************************************************************************* Any opinions expressed above are my own. Rich Andrews They can be yours too. Please send $19.95 to.....ihnp4!chinet!cabbie *******************************************************************************
cmcmanis@sun.uucp (Chuck McManis) (05/09/87)
In article <1068@bath63.ux63.bath.ac.uk>, (Paul Smee) writes: > Genlock for the ST was shown (working!) at the recent show in London. In > particular, it was being demoed for titling 'proper' video. Also, a > real-time digitizer box. Three questions for Paul or anyone on the other side of the Atlantic ... 1) Who makes the box, how much is it, and will they be doing an NTSC version ? 2) Can you use it with Hi-res mode? 3) How much does it cost ? Thanks, -- --Chuck McManis uucp: {anywhere}!sun!cmcmanis BIX: cmcmanis ARPAnet: cmcmanis@sun.com These opinions are my own and no one elses. But you knew that, didn't you.