This disc was provided by Toshiba to early purchasers of the SD2300 DVD player as a means of keeping their firmware up to date. To get one you had to fill out a form on their website and would then receive it in the mail. Below is the text archived from that webpage, including the serial numbers of the DVD players that required upgrading:

SD2300 Software Update

As part of Toshiba's on-going commitment to providing top-of- the-line quality to its customer, Toshiba will supply a free software update to all purchasers of the SD-2300 DVD player with any serial number from the list below.

To locate the serial number, please look on the back of your DVD player. If your DVD player is matched to any number from the list, then you need to obtain the free update in order to optimize the performance of your Toshiba DVD Player SD-2300 player.

0XCM100505 through 0XCM102000
0XCM200217 through 0XCM203370
0XCM400001 through 0XCM404630
09CM402147 through 09CM402184
09CM402209 through 09CM402232
09CM402257 through 09CM402280

To learn how your SD-2300 can be updated to the highest level of performance and to receive your free update software, please fill out the request form.