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#Enable/Disable switch

9 messages in this thread
#88286From: Bob JennichesAug 18, 1994 10:54 PM
I have a amiga 3000 with the toaster installed. On the back of the unitthere is an Able/ Disable swith on the lower rightback side of the computer. does anybody know what this switch is for? Also There are two Video ports on the back. One is 15 KHz and the other is 31 KHz. The one I'm using know is 15 KHz RGB (1084S) monitor. As you might be able to tell I'm new to Amiga. So bear with me and give me any info you can on these questions and anything else you can tell me that would be helpfull is appreciated.
#88293From: Jim SteeleAug 19, 1994 12:04 AM
The enable/disable swith on the back of the 3000 controls the 3000's built-in deinterlacing circuitry. If you have it enabled, you'll get 31.5 kHz video from the 31kHz port unless you go into the 1280 "superhires" mode. If you hook up a VGA monitor to that 31 kHz port, you will get rid of the annoying flicker that you get at the 15 kHz port when running in interlaced modes like 640 * 400. There are some monitors like CBM's 1960 that will scan all rates from 15kHz to 31kHz, but they are more expensive than a vanilla VGA monitor.
#88314From: Bob JennichesAug 19, 1994 10:45 AM
Hi Jim, With this 1084S monitor can I hook it up to the 31 KHz. port or not? And what kind of monitor would I need to get? On The back of the 1084S monitor there are two RGB inputs, One is TTL RGB with 8 pins and a LLI RGB input with 6 pins. Whats the difeance ond is tis configured right?
#88348From: Bruce Robertson [PreVue]Aug 19, 1994 6:01 PM
Bob, Should you decide to use the 31kHz video port, the 15kHz will need to be terminated when running Toaster CG scrolls or crawls. Otherwise, the unterminated RGB video, the source of the scroll and crawl, will be "hot" (about 2 times normal amplitude). NewTek used to send out the terminations with every Toaster Workstation. Heifner Communications used to have loads of them also. They're not difficult to build (only 3 75ohm resistors) if you need to go that route. ___ /__) ,_ _ _ _/__) / /__/ /_ /_-'
#88355From: Bob JennichesAug 19, 1994 7:16 PM
Bruce, Do you know what number pins are terminated. If you have the schematics for this so I can make one I would appreciate it.. Also can I use the 1084S monitor on the 31KHz video port? Thanks Bob
#88392From: Bruce Robertson [PreVue]Aug 20, 1994 2:39 PM
Red is on 3, Green is on 4, Blue is on 5, and Grounds are on 16 through 20. Wire on 75ohm resistor from Red to Ground, one from Green to Ground, and one from Blue to Ground. I once made up a custom, adjustable terminator for a guy who wanted his RGB-viewed colors to match his NTSC-viewed colors. Rather than use a 75ohm resistor for each color, I substituted a fixed resistor (51ohms) in series with a potiometer (50 or 100ohms) to allow tweaking the colors to match. You end up with, say, one terminator being 70ohm, one at 80, and one at 85. It worked great. You 1084 will scan at 15.7kHz only. Its forte is the ability to display composite, Y/C, and component video signals. You can literally find 31kHz monitors anywhere these days, cheap too. With your built-in de-interlacer/scan doubler, you should be able to get by without any 15kHz RGB monitor, which are getting hard to come by. If you want to cover your bases, use the 1084 as your Toaster Preview monitor, keeping it cabled to both your RGB port and the Preview BNC. With a push of a button, you will be able to switch back and forth. The 1084 also takes care of the termination problem.
#88371From: Jim SteeleAug 20, 1994 2:36 AM
Bob, No, you can't hook the 1084S monitor to the 31 kHz port… unless you make a special cable and leave the switch in the 'disable' position. That would make it the same as the 15 kHz port, so there's no real point in it. The 1084 is strictly a 15.75 kHz monitor. As to the two RGB inputs, one is TTL RGB – used on clones for CGA display and (I think) some of the C-128 machines. You're limited to 16 colors, since the R,G & B are either full on or off… plus an 'intensity' bit. The Amiga uses the analog RGB mode to display all 4096 or more colors. The exact connection varies since there's half a dozen slightly different versions of the 1084. If you want to use the 31 kHz port, a standard clone type VGA monitor will work fine, so long as you don't go into one of the display modes that automaticaly disable the 3000's deinterlacer. (1280 x whatever). The best choice would be a multisync monitor like the Commodore 1960, but I don't think there are many available these days. I did notice some of the mailorder places selling some custom multiscans as a replacement for the 1960. The problem is that you want a monitor that goes down to 15.75 kHz if needed. Those are rare these days. Jim
#88393From: Bob JennichesAug 20, 1994 5:02 PM
Hi Jim, So what am I better at using? The 15 hz or 31 hrz Also can I use my INB monitor on the Amiga? It's a SVGA monitor. Thanks bob
#88335From: Anthony RamirezAug 19, 1994 3:11 PM
>On the back of the unit there is an Able/ Disable swith on the lower >rightback side of the computer. does anybody know what this switch is >for? This is the In/Ex Genlock Compatibility switch. It is for using the Display Enhancer (31 KHz) and a genlock. The 2 video ports are for RGB display (15 KHz, like the 1084) and the other is for MultiSyncs (like 31 KHz), or VGA.