Map This!/Requirements

A PlayStation Portable is required to use Map This!

A Sony PlayStation Portable (PSP), either fat or slim;
A homebrew capable firmware (e.g. 1.50, OE or M33 firmware);
Enough space on your memory stick for Map This! itself and one or more maps;
A GPS receiver (e.g., PSP-290, Holux GPSlim236, Starsnav BT-74S).

Homebrew capable firmware

Since Map This! is a homebrew application, you will need a PSP firmware that supports homebrew. This can be either official Sony firmware 1.50 or a custom firmware (CFW), e.g. one of Dark_AleX' firmwares.

Enough space on your memory stick

Map This! will take about 7MB of space, including a small sample map. However, to store your own maps you will need more space. Depending on the areas and the amount of detail you need, this may add up to several hundred megabytes. You should find out for yourself how much detail you will be able to store.

GPS receiver

Map This! distinguishes two different kinds of GPS receivers. One is connected to the PSP using the mini USB port, the other using the serial port (next to the headphone connection). So far there is only one GPS receiver that can be connected to the mini USB port, namely Sony's PSP-290 GPS receiver. The following GPS receivers can be connected to the serial port:

Holux GPSlim236;
Holux GPSlim240 (baud rate needs to be 4800);
Holux M-1000;
Starsnav BT-74S.

For these GPS receivers you will need a separate data cable to connect the GPS receiver to the serial port. This cable can either be homemade or purchased online. A cable for Sony's PSP-290 is not necessary.

The following receivers have been reported to work (using serial communication and NMEA), but the overall setup is usually more complicated and it's hard to officially verify it:

HOLUX GR-231 (use the default read time of 1, no need of resistor – some say it only works without this but try with a 1k resistor first to be on the safe side);
HOLUX GR-230;
GlobalSat BR-305;
Pharos GPS-360 (baud rate needs to be 4800, set read time to 2);
Garmin GPSmap 60C (baud rate needs to be 4800).

GPS receivers that are connected to the serial port are referred to as "generic".