scottyau

While I have been reading and building a few things on my own, process is a little slow going due to time constraints.  It's probably going to be a little while before I have any boards in hand that are of my own design.  So to scratch my soldering itch I ordered some very cheap kits off eBay a little while ago.  No other motive in mind with these other than just a bit of fun putting them together.  There are kits available locally, but none of them are this cheap.  If they were things I might put to use I'd be happy to spend a little more, but as these will probably just got on my shelf of bits - the cheaper the better.  The first two were through hole clock kits, $5.60 and $7.70 respectively (including postage).   They actually arrived quite quickly.   Kit no. 1: Both kits have a PDF with schematic and contraction details.  The PDF is not required for construction though thanks to the detail on the silk screen.  Kit no. 2: ...

I bought something off eBay about 2 weeks ago now and it arrived yesterday: As the title suggests - a Commodore 128 .  I've wanted a Commodore 64 or 128 for a long time but they always seemed quite expensive on eBay.  This one is a complete gamble.  Sold as is - untested - due to there being no power supply and video cable to test with.  It was however priced appropriately for a change and in Australia.  So I rolled the dice.  The auction included just the unit itself and a copy of the Commodore 128 System Guide: The outside cover is a bit poor but the inside pages are like new.  Interesting British stamp printed on the front.  I also found a note inside the guide on a bit of paper about how to load a program from disk.  What was interesting about this hand written note was the paper the note was written on: Check out that offer expiry! I have a power supply and video cable en route which I'll put some more inf...

I finally pulled the trigger and bought a bench power supply.  Up until this point I have just been using the ATX breakout board .  I've been looking around for a while, trying to way up price vs features and finally settled on the Siglent SPD3303D . The supply has 2 fully adjustable channels that can work in independent, series and parallel modes.  The 3rd channel switches between 2.5v/3.3v/5v at 3A.  The display only covers the first 2 channels, the 3rd channel just has the LED displaying CV/CC mode.  The 2 adjustable channels also have a timer function which can be programmed either on the supply itself or via USB using the included software (just like other features). I settled on this guy because it ticked all my boxes - and physically was the right size for my shelf as well. There is quite a lengthy thread on this particular supply here  on the EEVBlog forum.  This thread mentions two issues found with the supply - namely: Spikes / ov...

Just like playing with micros I wanted to get my hands on and play with come CPLDs so I went hunting around for some tutorials.  The one I settled on to start with was this one .  It uses a CPLD from the Altera MAX II family.  The chip itself is not overly important but the branding on the chip is - as this is basically an exercise in learning how to use a the associated vendors software.  I found the same boards used in the tutorial here , ordered and waited for delivery. Once the boards turned up I opened one up and noticed that the board was not very clean.  There was a lot of extra flux and other gunk on the board.  It worked - it just wasn't clean, so I thought I'd have  go at cleaning it. After googling around I found a lot of people using a lot of different ways of cleaning their boards.  At lot of people talked about just washing it with some warm soapy water, or even putting it through the dishwasher.  I found this completely wei...