Serial ports
I still use them because they're easy to program. USB's are a pain in the arse. Sadly these ports are disappearing fast.
(Archeleus hates cabbage, Fri 5 Nov 2010, 11:18, 7 replies)

Yeah too right
Before the days of memory sticks, the best way to transfer shit between two computers was via hyperterminal serial port. Just worked out of the box, no messing about. Saved my ass a number of times. Putting a 4mb network card driver on a PC which had no CD Drive, and was running NT4 was done via Serial on hyperterminal. Then once the ports started disapearing off new laptop it became a nightmare.

To this day we still keep some older laptops which the network guys use to program cisco switches and stuff, because even with the USB to Serial adaptors they have problems sometimes.

You cant beat legacy RS232!!
(Miggyman, Fri 5 Nov 2010, 11:22, closed)

Voltage levels?
Corners are often cut with the voltage levels. According to Wiki the original spec (1969 or so) says the driver is meant to output at +/-12V and the receiver is meant to recognise signals down to +/-3V. I just measured my own equipment (fnar) and my USB adapter gives 7.74V but the PCI card in my desktop gives 11.46V.
( idonthaveafunnynickname Drink-Aware? Sure. I'm aware I want another drink., Mon 8 Nov 2010, 1:41, closed)

Well, they tend not to come as a standard output anymore, but the header is still there on the vast majority of modern desktop MBs - easy enough to plug a db9 pin extension cable in...
( Happy Phantom has been to Hastings, Brighton, and Eastbourne too, Fri 5 Nov 2010, 11:24, closed)

USB- 232 convertors work as well
At least they generally worked for comms in custom install.
(Leonard Hatred briefly did some work on, Fri 5 Nov 2010, 11:26, closed)

The converts are okay enough for some DIY projects
but I'd not trust it as much as I do the direct connections. Also, you've to install some custom drivers if I'm not wrong.
(Archeleus hates cabbage, Fri 5 Nov 2010, 11:28, closed)

True
But they are free and don't seem to affect the ports wheen being used for USB. I've had cause to use the same connection for RS232 and 24/96 High res music files on the same day without any headache.
(Leonard Hatred briefly did some work on, Fri 5 Nov 2010, 12:20, closed)

Me too
As I like to play with vintage computers and build some of my own. I don't think they make USB controllers for the Z80 or 6502.
( idonthaveafunnynickname Drink-Aware? Sure. I'm aware I want another drink., Mon 8 Nov 2010, 1:10, closed)