I've been playing about with a few more electronics bits and
pieces, but haven't had the chance to write them up (yay, babies!), so
to keep up the momentum I thought I'd put up a few notes:
- As I ultimately want to make a simple 8-bit computer, I need to
program EEPROMs. I thought about making my own programmer, but I
discovered that the ZIF sockets at Farnell at 10 quid, and a full
'Willem' programmer, off Ebay, with cables and delivery from China can
be yours for 21 quid. Gah. No contest, really. The downside is that I
don't learn from building and debugging my own, the upside is that I
get straight to my goal and get a much more mature design. Ho
- Then... I checked Ebay for ZIF sockets, and you can get similar
sockets for a couple of quid. So, I could have built it from scratch
quite cheaply. Ho hum. Apparently the rule is that if you're looking
for this kind of component, do check Ebay first!
- Add simple safety features! Unlike programs, an error can't always
be fixed and the program re-run, as one of the components may now be
smoke. For what I've been doing, these features come to power-on LEDs
and resistors between most things. Resistors in series with pots stop
the resistance going to zero are useful, and any time I'm uncertain as
to whether a certain configuration could lead to the same point being
driven to different levels, I bung a resistor in.
- Learn to use your multimeter. Ok, that sounds obvious. Learn to
use your multimeter effectively. I've got a fairly fancy meter,
and i's been increasingly useful as I learn its features. On the other
hand, I've found the best way to learn to use it is in practical
situations, rather than by just reading the manual.
I've played a bit with voltage regulators, SRAM and EEPROM since
writing last, so hopefully I'll manage to write those up soon...