Elf Turns 30
■ by Robert Armstrong -------------------------------> Part 2
Welcome back! Last
month, we printed the
schematics for the Elf
2000 and discussed the operation of
every part of the circuit. This month,
we’ll print the parts list, talk about the
construction and testing of your Elf
2000, say a few words about the
available software, and then finish up
with ideas for expansion.
it’s a lot more fun if you use a PCB
(printed circuit board). A pre-made
PCB is available from http://
elf2k.SpareTimeGizmos.com and,
not only does it make wiring faster
and easier, but it makes it a lot less
error prone, as well.
Assembling the Elf 2000 is a
straightforward process of inserting
the parts into the PCB and soldering
them. Here are a few tips that will help
you avoid any problems:
• Notice that capacitors C1 and C2
are polarized devices and must be
installed correctly. The polarization is
shown on the silkscreen of the PCB.
• Header J5 (the switch panel
connector) should be mounted on the
bottom (solder side) of the PCB with
the pins facing “down.” Because of
the limited space available, don’t use a
shrouded header for J5.
Construction
You can construct the Elf 2000
using wire wrap or point-to-point
wiring, just like the original Elf, but
• Twenty-one 0.1 μF 50 VDC monolithic bypass capacitors are used in the Elf
2000. On the PCB, these are identified
only by a box on silkscreen.
• If you intend to use the STG1861
“Pixie” emulator, then do not install
a DIP socket at U2 (the CDP1861
socket). The STG1861 daughter board
uses special 0.1” female headers and
will not mate with a standard DIP
socket.
• Remember to use a
heatsink with VR1.
If you’re a
relative novice
Elf 2000 with “hands” — a clone of the
original 1976 P-E/Cover shot with an Elf 2000.
