Conference 7.286::atarist

    If you don't mind the money, buy a good RGB monitor like the SC1224.
    
    Otherwise,
    
    I have an RF modulator installed on my 1040, so it is now like it
    was intended by its designers. (I suspect marketing took it out).
    
    It is not difficult to install however, I ran into a few problems.
    If you open your ST, you will notice two things:
    
    	1) there are already some components on the RF modulator location.
    
            This is no problems, these components (one transistor, two
            diodes, a few resistors are there to build the COMPOSITE
            SYNCHRO that you find on monitor socket pin 2 on all the
            1040's. You have to take those components out, as when
            the RF mod is installed, pin 2 holds the COMPOSITE VIDEO signal.
    
        2) there are some components missing inside the shifter shield.
    
            The so called RF modulator is in fact a color coder with a
            RF modulator build in. This is why there is no composite
            video on the 1040. The color coder chip needs a fixed frequency
            of 4.43 MHZ (for PAL, 3.579 (?) for NTSC). 
            It is this oscillator wich is missing on the board.
            Also, the color frequency and the HSYNCH seems to be used
            to synchronize the 32MHZ PLL (wich drives the shifter, the
            shifter builds the RGB and monochrone signals from the screen
            data). This requires one 74HC74 chip and one more transistor.
    
    If you install all this it works. BUT there are several revisions
    of boards, and the oscillator has changed. I had to reconstitue
    the schematics of the oscillator from the board itself and experiment
    for the components values.
    
    You have been warned. The modification is not difficult. You will
    enjoy it if,
    
    	you want to play some games on your TV set. 
        you want to record your pictures or whatever on your VHS recorder.
        you already have a composite video color monitor
        you want to take your ST with you on trips and use the Hotel
        TV set.
    
    If you intent to buy a color monitor, BUY an RGB, it is still much
    better in mid resolution. Low resolution is pretty good still. 
    

    Best Electronics, (408)243-6950
    
    I don't have the address in front of me.
    
    	Ray

re: .3 

Thanks for the phone number.  Worked like a charm!

re: .1

I called up BEST co. and spoke with Brad (?) and he explained that the
RF adaptor that they sell (model CB 101491) is $50 and he did what he
could to dissuade me from buying it.

He said installing it required 1) cutting out some components, which I knew,
thanks to .1 above, and 2) tuning it properly which would require a color
burst generator and oscilloscope.  BEST will do the whole thing for $100
(parts and labor) plus shipping.  You send them the mother board and they
modify it and ship it back.  But he suggested buying a Video Key from someone
else instead!

Is it really that rough?  Is the kit complete or must other parts be purchased?
I don't really have access to an o'scope & generator.  Is it mandatory?

Thanks for any info.

Rich Murray

    Is there such a thing as an external RF modulator for the ST?  
    
    I have been looking at buying a package of stuff which includes an old
    520 with external drive.  The owner does not know if it has an RF
    output (I asked him to look, sounds like he has no idea what I'm asking
    him).  I was thinking of donating the 520 to a friend but need an RF
    modulator if the 520 does not have it.
    
    Am I correct that some early 520s did not have an onboard modulator?
    
    							Brian

    As far as I recall, this was normally indicated by the model id
    e.g.
       520 ST   = Really basic, no floppy, no modulator
       520 STF  = Floppy, no modulator
       520 STFM = Floppy & Modulator
    
    (I'd expect that it doesn't have one although but I think that you can
    still get them added internally)