Altronics Colour Maximite - Mystery Cap

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Keith W.
Senior Member

Joined: 09/10/2011
Location: Australia
Posts: 118
Posted: 12:14am 09 Dec 2012      

I also have built the Altronics Colour Maximite. I was looking for the 10uf capacitor because of previous discussions about requiring a special cap but thought it missing, nearly threw out the tiny smd.

My unit worked immediately and displayed colour and ran programs. Although I was able to update the MMBasic via USB I experienced trouble when attempting to use TeraTerm via USB. I discovered that I had only 4.51 volts from the USB connection post the supplied 1N5819 Schottky diode, 3.3 volt supply OK. I was using 2 (short) USB cables in series. Removing 1 cable lifted the supply a little and it then worked. Using a computer USB port that is mounted directly on the motherboard raises the voltage another 0.01 volts. During software update the power LED is turned off and the voltage rises by 0.01 Volts.

With my original SM1 Maximite I originally achieved 4.57 volts and have no problems with the cables in series. My Gigabyte motherboard and computer supply are about 1 year old.

Using a DC supply all works OK with the diode dropping 0.32 volts from the regulated 5 volts. Perhaps with some computers the Colour Maximite MAY be marginal for USB communications when powered from the USB only. The USB port and cable used seem a factor when powering the Colour Maximite.

An interesting question for GeoffG is that I think it possible for USB devises to specify the current to be supplied to them. What is the case with the Maximite?

Regardless of the above my Colour Maximite with MMBasic V4.1 is fantastic.

Keith W.