Re: Asteroids display problem

GETTING them isn't the problem. Paying less than $30 each is the
problem.

I did find a Maxim chip that would work, but would have to plug into an
adapter board. Might be able to do the entire assembly for $10.

Matt Rossiter wrote:
>
> Has anyone tried this site? http://www.broker1.tv/index1.html?all
>
> It seems like you can find just about anything here, but you'd probably
> need to be willing to buy in bulk.
>
> Matt
>
> Phil Morris wrote:
>
> > At 22:57 15/06/2002 -0500, you wrote:
> >
> >> I guess it's time to start rooting out an inexpensive replacement. Wish
> >> me luck.
> >
> >
> > No-one has yet mentioned the alternative to the AD561J - the AM3012
> > (or modern day equivalent, the DAC312HP). Much cheaper than the AD561J
> > and readily available.
> >
> > However, it's not exactly a drop in replacement - there is provision
> > for it on the board (look at the the existing AD561J DACs and you'll
> > see two unoccupied pads). You'll need to therefore add a suitable
> > socket (or solder the DAC directly to the board if you wish) BUT
> > you'll also need to add the support components, ie caps and resistors.
> > It WON'T work unless these are added. I know, I've tried.
> >
> > This is a lot easier on rev 5 boards and later (as mentioned, I've
> > done it and it works just fine) but on earlier boards (such as rev 2)
> > the locations of the AM3012 support components aren't marked on the
> > board, plus there is one resistor pad missing (easy enough to attach
> > the resistor though).
> >
> > The Asteroids Deluxe schematics will provide you with the relevant cap
> > and resistor values, but as I've done the mod myself I decided to note
> > them down, as follows:
> >
> > Asteroids Rev 05 board:
> >
> > AM3012/DAC312 at D12:
> >
> > R148 = 10K +/- 5% 1/4W Resistor
> > R149 = 10K +/- 5% 1/4W Resistor
> > R150 = 4.7K +/- 5% 1/4W Resistor
> > R151 = 10K +/- 5% 1/4W Resistor
> > R152 = 8.2K +/- 5% 1/4W Resistor
> > C124 = .1uf Ceramic Disc 25v Radial Lead Capacitor
> > C125 = .1uf Ceramic Disc 25v Radial Lead Capacitor
> > C126 = .1uf Ceramic Disc 25v Radial Lead Capacitor
> > C127 = .1uf Ceramic Disc 25v Radial Lead Capacitor
> > C128 = .1uf Ceramic Disc 25v Radial Lead Capacitor
> >
> >
> >
> > AM3012/DAC312 at B12:
> >
> > R153 = 10K +/- 5% 1/4W Resistor
> > R154 = 10K +/- 5% 1/4W Resistor
> > R155 = 4.7K +/- 5% 1/4W Resistor
> > R156 = 10K +/- 5% 1/4W Resistor
> > R157 = 8.2K +/- 5% 1/4W Resistor
> > R158 = 2.2K +/- 5% 1/4W Resistor
> > C129 = .1uf Ceramic Disc 25v Radial Lead Capacitor
> > C130 = .1uf Ceramic Disc 25v Radial Lead Capacitor
> > C131 = .1uf Ceramic Disc 25v Radial Lead Capacitor
> > C132 = .1uf Ceramic Disc 25v Radial Lead Capacitor
> > C133 = .1uf Ceramic Disc 25v Radial Lead Capacitor
> >
> >
> > Early revisions of Asteroids boards (for example, Rev 2) that have no
> > location markings for these extra components yet that do have the
> > ready-made yet
> > solder filled holes:
> >
> > Same as for Rev 05, BUT the location R158 is missing from the board -
> > to fit R158,
> > attach one lead to the left hole of R157 and the other lead to the
> > metal ground that
> > is so prevalent in this area
> >
> >
> > Asteroids Deluxe Rev 01 board:
> >
> > AM3012/DAC312 at C/D11:
> >
> > R81 = 10K +/- 5% 1/4W Resistor
> > R82 = 10K +/- 5% 1/4W Resistor
> > R89 = 4.7K +/- 5% 1/4W Resistor
> > R90 = 10K +/- 5% 1/4W Resistor
> > R119 = 8.2K +/- 5% 1/4W Resistor
> > C52 = .1uf Ceramic Disc 25v Radial Lead Capacitor
> > C53 = .1uf Ceramic Disc 25v Radial Lead Capacitor
> > C80 = .1uf Ceramic Disc 25v Radial Lead Capacitor
> > C90 = .1uf Ceramic Disc 25v Radial Lead Capacitor
> > C91 = .1uf Ceramic Disc 25v Radial Lead Capacitor
> >
> >
> > AM3012/DAC312 at A/B11:
> >
> > R83 = 10K +/- 5% 1/4W Resistor
> > R84 = 10K +/- 5% 1/4W Resistor
> > R91 = 4.7K +/- 5% 1/4W Resistor
> > R92 = 10K +/- 5% 1/4W Resistor
> > R124 = 8.2K +/- 5% 1/4W Resistor
> > R125 = 2.2K +/- 5% 1/4W Resistor
> > C54 = .1uf Ceramic Disc 25v Radial Lead Capacitor
> > C56 = .1uf Ceramic Disc 25v Radial Lead Capacitor
> > C82 = .1uf Ceramic Disc 25V Radial Lead Capacitor
> > C90 = .1uf Ceramic Disc 25v Radial Lead Capacitor
> > C97 = .1uf Ceramic Disc 25v Radial Lead Capacitor
> >
> >
> >
> > Hope that helps someone,
> > Phil
> >
> >
> >
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Received on Sun Jun 16 14:18:37 2002