From The Dragon Archive
Dragon 16K - codename "pippin"
The dragon originally started out life as a 16K prototype code named "Pippin" (hand built by PA Technology in Cambridge in October 1981 for Mettoy) as part of project SAM and has started production when Sinclair launched the 48K Spectrum as the successor to the earlier 16K model. A number of early prototypes were built by hand, some complete with dental material based cases, and today only one example of the "pippin" is known to still exist.
Apart from the missing additional 16K the prototype was almost identical in design to the Dragon 32 that became the launch machine. What is not commonly known is that the 1st 10,000 Dragons were manufactured as 16K machines. The decision to move to 32K came too late in the process to change the production run and these machines had to have a 16K "piggy-back" RAM board fitted at the factory to make the Dragon 32.
In the photos of the 16K "Pippin" prototype you can see the PSU, PSU\Video Output board, keyboard (from Hi-Tek but with original keys) and the motherboard. Notice that all are made on simple etched boards and that the keyboard connector is different to the Dragon 32, also notice the missing cartridge connector, although the header is there for it to be soldered on and missing power button. The 8x16Kb 4116 DRAM chips would give this machine a total of 16K RAM. What you can't see in these photos is the number of patches done by hand to the underside of the board.
Many thanks to Richard Harding for taking these photos and extended thanks to the owner of this machine for letting him visit.