[Coco] (no subject)

[Francis Swygert]

The Power Supply Repair section of "Tandy's Little Wonder" (starts on page 89, http://sparksandflames.com/files/TandysLittleWonder-2nded.pdf) has the connections for a standard PC power supply. These can also be used to supply 5V DC directly to the motherboard. You would need a 5V regulator but could otherwise run directly off a 12V battery. That would greatly increase battery life over using an inverter. Some have made totally portable CoCos this way. I seem to recall that you lose the RS-232 port unless you have both +12V and -12V though, at least on the CoCo1. I don't think you need 12V on the CoCo 2 and 3, but would need -5V for the RS-232 to work... don't really remember. The text isn't clear on this, but just gives voltage requirements for +5V and -5V for the 2 and 3... but also shows where to connect a PC power supply's +12V and -12V. If indeed you just need +/-5V a couple small regulators with heat sinks is all you need for a PS that will plug into your cigarette lighter. It should carry 3A (CoCo 2/3 requires 2.1A total) with no issues. Then you just have the TV/monitor drawing on the inverter... but many of those use an external brick power supply of 12V...
 Frank Swygert
 Fix-It-Frank Handyman Service
 803-604-6548