I decided to remove the RS-232 interface chips (2 each of 1488 and 1489) and connect a USB serial interface directly to the Z8440 (Z80 SIO/0), avoiding all the malarkey with RS-232 voltage levels. I won't have the hardware handshake signals but these days equipment can keep up with 9600 baud without blinking an eye.

I first used a soldering iron and solder sucker, but that didn't work so well for this two sided board. The next time at work, I got some time on the Hakko vacuum desoldering gun but this hasn't been maintained so the vacuum is weak.

After a moment's hesitation I decide to snip the chips out. I am adverse to destroying working stuff, but I have heaps of RS-232 chips which I'll probably never use up in my lifetime. I still had to remove any pins that broke off the chip package. This is what I ended up with. It isn't pretty but it's ready for the next stage.

While I was at it I also removed the 7805 voltage regulator and soldered in a connector so that it could be wired up to a 5V power pack.