Video on a scope is great, but let's watch it on screen!
Small, smaller, smallest...
Falonn over at AtariAge has developed a great, open source RGB circuit called TMSRGB that we'll be using on this board as well. Unfortunately some of these ICs have tiny footprints, but that's just the way it is. Just start with the two smallest ones, and double check for solder bridges:
U28 LMH1251MT (TSSOP24)
U29 THS7374IPW (TSSOP14)
U30 TS5A4597DBV (SOT23-5)
U32 74LVC2G17DBV (SOT23-6)
Note: watch for the correct orientation of U32! The "writing" must be "upside down"!
You can continue with the remaining three ICs, which are in the usual SO packages you know well by now:
U26 4053D (SO16)
U27 MAX4395ESD (SO14)
U31 LM1881M (SO8)
Now, throw in a bunch of identical 100nF capacitors:
C61, C63, C64, C65, C66, C67, C70, C71, C72 100nF
Then
C53 10nF C0805
C69 10uF/16V X5R C0805 (that's MICRO-Farad!)
And finally a bunch of resistors, some with weird values. But those are needed to get the colours right, so stick to them:
R44 560k
R45, R49, R52 910
R46, R50 680
R47 270
R48 620
R51 10k/1% (!)
R53 5k6
R55 75
R56, R57, R58 0
To output RGB we're using a standard Mini-DIN jack that e.g. Sega Genesis 2 cables use. These cables include 75 Ohm resistors, so R56-R58 are 0 Ohms. In case you're using some other cable, you need to use 75 Ohms resistors for R56-R58! The jack is available from Mouser:
J3 Kycom KMDGX-9S-BS-1
The Genesis 2 Cable can output composite video or just composite sync on SCART. Use SJ5 to select either. If you are planning on using the Expansion Module #1, you need to set SJ5 to Composite Video and also install SJ12 as well as populate the video buffer circuitry!
Also, SCART requires a switching voltage to switch to RGB, set SJ13 to 5V. If your TV requires 12V, set SJ13 to 12V, but then you need to populate the (relatively expensive) 12V DC/DC converter DCDC2. But be careful, the SCART standard limits this to 5V so think twice before setting it to 12V! This is the reason the jumper will no longer be present starting with Rev.C of the board.
Again: Video!!!
Hook up a TV, and you should see the ColecoVision welcome screen:
Note: my camera really sucks at capturing colours off of a TFT TV screen...
But getting this far hopefully motivates you for the next episode!.
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