[Coco] Unknown Coco 2 - Socketed

Glen VanDenBiggelaar glenvdb at hotmail.com
Fri May 31 00:52:13 EDT 2013


"26-3026
This is the first model of CoCo 2. Built in the USA, it came equipped with 16 kilobytes of RAM, Color BASIC only, and the 'melted' keyboard. Most of its chips are socketed. This machine is based on the &8709416 PC board, and has a large, upright RF modulator with integrated TV channel 3/4 switch. Also characteristic of this machine is the use of a large power supply pass transistor (in a TO-3 package). The two 24-pin ROM sockets are located near the cartridge/system bus connector, and the eight RAM chips are located in a single row under the keyboard.
(Note that this same model number has reportedly been found on larger, Korean-made CoCo models in Australia.)
26-3027
This machine is identical to the 26-3026, with the exception that it already has the Extended BASIC ROM factory-installed.
To upgrade the 26-3026 or 26-3027 to 64 KB of RAM, it is necessary to replace the eight 8040517 chips with 4164 chips of 200 ns or better access time, and to solder a wire between the two pads labeled W1. W1 is located between U6 and U7.
26-3127
This is the first '64K Color Computer 2'. It contains the Extended BASIC ROM, the 'enhanced' keyboard, and 64 kilobytes of RAM (naturally). Otherwise, it is identical to the 26-3026/26-3027. Note that the RAM is soldered in place in those machines which were factory-equipped with 64K, making replacement thereof a bit more difficult if necessary. For this reason, the 26-3026 and 26-3027 variants are favorites of the author."


>From Techno's page, notice the 3026 has the "416" PC board , so if this is a "3126" like that DYI kit, with 64k, it would kind of make logical sense. A side note I didn't see a 3126 listed. 		 	   		  


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