During the last month several new spam networks have been flooding my servers. Instead of being just a few IP addresses here and there, they’ve been using huge subnets to send their spam. My old system of banning single IP addresses just wasn’t keeping up. Last week I started working on a new system that would be better able to track messages as they are handled by my mail servers. I run about a half-dozen mail servers for myself and for clients, and I’ve set them all up so...

A cassette adapter works, but is less convenient It’s been a while since I last made a PCB  but I finally had need to make another circuit board. The board I needed to make this time was a simple circuit that would be installed in a ZX Spectrum +2B which would bring the record and playback lines out to standard headphone jacks so an external source like a smartphone could be patched in instead of having to use one of those cassette adapters. It came about because when the...

Ever since I did BBS Week on RetroBattlestations , I’ve been wondering if there’s a way to use a modem without having to use a land line. It seemed like it should be possible since modems work with T1 lines, and T1 lines are digital. However when I experimented with it during BBS week, I didn’t have a PBX that I could use to interface to an analog line, and I didn’t have any modems with an acoustic coupler. I decided to setup an Asterisk PBX and get the cheapest card...

Yesterday I went to cut out some new stickers in preparation for the next theme week on RetroBattlestations . I loaded the design into the program, repeated it a few times on the page, and told it to cut. After it was done I cut the stickers apart and started to weed them but found it hadn't cut all the way through. And there were also a lot of scrape marks on the vinyl where the knife moved from one path to another. It only took a moment to realize what had happened, the cutter head...

A lot of the auctions I win on eBay are for items that are listed as “untested, as-is, for parts or repair.” While the sellers will post lots of pictures, they often won’t do any kind of research or investigation of what they are selling. This is great for me because 9 times out of 10, the thing I bought actually turns out to work just fine and doesn’t need any repair at all. And with computers it’s not unusual to find some nice upgrades have been installed that...