jdc3538@ritcv.UUCP (Jim Cronin) (03/21/88)
I would like to recycle some unused TV's for computer use. Have any of you ever attempted adding a direct video input? Wouldn't it have to go right after the I.F amplifier? Is there any way to add RGB inputs? Now THAT would be a handy thing to have. Thanks...Jim
krc@cs.purdue.EDU (Kenny Crudup) (03/30/88)
In article <283@ritcv.UUCP>, jdc3538@ritcv.UUCP (Jim Cronin) writes: > I would like to recycle some unused TV's for computer use. Have any of you > ever attempted adding a direct video input? Yup. Works Ok, but forget composite 80 x 24 color. (Even as RGB, see below) Either use a cold-chassis set, or *USE AN ISOLATION TRANSFORMER*. Forget any thing with tubes in it. That wreck.audio tube purist bullshit doesn't carry over to video. It *can* be done, but you'll have real *fun*. > Wouldn't it have to go right after the I.F amplifier? Better than that- do it after the 1st video amp, just before the video output. It has to be before sync separation, unless you intend to pipe in sync yourself. Remove *all* the traps, filters, 3.58/4.5 ceramics etc. Once I made an AC- coupled $45 b&w tv set into a DC-coupled monitor with decent resolution. Damn good. Just moved around a few parts and stuff. No real hassle. Get a Sams for the set, of course. > Is there any way to add RGB inputs? Now THAT would be a handy thing to have. Yes, but depending on your set, it rides on a voltage level used for setting brightness/picture. This is usually the case for discrete (several transistors as opposed to all-on-one-chip-like-Sanyo Tv's). The everything on a chip sets are a little bit better for this. > Thanks...Jim No problem. -- Kenny "_R_o_b_o_B_r_o_t_h_e_r" Crudup krc@arthur.cs.purdue.edu Purdue University CS Dept. W. Lafayette, IN 47907 inews: Error code 257: .signature +1 317 494 7842 joke too stupid: Not included
markz@ssc.UUCP (Mark Zenier) (03/31/88)
In article <283@ritcv.UUCP>, jdc3538@ritcv.UUCP (Jim Cronin) writes: > I would like to recycle some unused TV's for computer use. Have any of you > ever attempted adding a direct video input? Wouldn't it have to go right > after the I.F amplifier? Is there any way to add RGB inputs? Now THAT would > be a handy thing to have. > Thanks...Jim A problem is that TV's are cheaply built and may not have any isolation from the power line. Plug your TV in backwards and your computer blows up. (This happened to some poor soul up here in Seattle about 10 years ago, and the local club got together and scrounged up all the chips necessary to rebuild his altair) Some older sets run with a rectifier right on the power line which feeds everything. These are bad news. Newer sets use the Horiz. drive as a switching power supply so most of the circuitry is isolated. Check out the TV typewriter Cookbook by Don Lancaster for B&W mods. From Sams about 1976 but it may still be in print. You will probably be dissapointed in the resolution of the display since when selling a TV, It only has to look better than the one next to it in the display room, and cost is everything. Anything new enough to have decent resolution probaly has a direct input already. As to RGB, it will be easier to add this than composite to some sets. Mark Zenier
simon@ms.uky.edu (George Simon) (04/10/88)
[-] Oops - mailer ate my signature ...... <---------------------------------------------------------------------------> <--- Simon Gales@University of Ky 254-9387/257-3597 ---> <--- [simon@ms.uky.edu] | [cbosgd!ukma!simon] | [simon@UKMA.BITNET] ---> <- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -> <--- Somewhere amidst millions of blocks of disk space is at least one ---> <--- with my .signature in it. Hopefully this will be one of them. ---> <---------------------------------------------------------------------------> [-]
larry@pdn.UUCP (Larry Swift) (04/12/88)
In article <8873@e.ms.uky.edu> simon@ms.uky.edu (Simon Gales) writes: > > If converting a color TV to RGB is not easy, how about doing the same > to a color composite monitor... How good of an RGB could I get? Gotta be just as bad -- a lotta stuff you'll need just isn't there in a composite. Why not just get an RGB monitor? It just so happens I've got an analog one, 19", open frame, that I'll sell cheap. Larry Swift UUCP: {codas,usfvax2}!pdn!larry Paradyne Corp., LF-207 Phone: (813) 530-8605 P. O. Box 2826 Largo, FL, 34649-9981 She's old and she's creaky, but she holds!