Around time when I was beginning to learn about microcontrollers I had exchanged my laptop with a senior at college for his desktop – that’s because the only way I knew how to program an ATMEGA chip was through either a serial port or a parallel port. USB programmers were not available widely and were generally thought to be expensive. The programming setup using a parallel port was very simple. I followed the DAPA programmer for my needs for some time. Here is a pic of the setup – ATMEGA8 chip on breadboard (pinouts matched against the one shown in above link), a parallel port DB25 connector and a USB cable that just to get 5V and GND quick and dirtly without any batteries and voltage regulators:
Over the time I learned about an inexpensive way of making a USB based AVR programmer called USBasp. It’s faster, cheaper and has the convenience of letting you program AVRs from laptops. Here is a pic of the first USBasp programmer that I built, and promptly got my laptop back (in the link you can see more designs):
Plugging it into the laptop and seeing it get recognized was pure fun! Having it work right also meant that you could get it to a competition venue easily, in case you had to program the microcontroller again…
Without this the only other way was to bring along a desktop which was just impractical. I can recall once at the IIT Techfest I had found a team bring a really old laptop which did have a parallel port and those folks were programming their chips on the spot and it just didn’t feel fair for the rest of us… heh heh! I used this one for a long time, even took it to workshops at college and many came from time to time to get their microcontrollers programmed.