LINK DISC: How to play extra CE charts on any PSP DJ Max Portable: Black Square

So Clazziquai and BS (Korean version) are both pretty hard to find physically now, and most people are likely playing the games via ISO. That said, a few topics on here talked about how to enable the link disc function for the games, but the threads are 1. Six years old, and 2. Inaccurate.

After fiddling around on two of my PSPs for a bit, I've figured out how to enable Link Disc in Black Square for any PSP model (it worked on my 3000 and Go), without needing a UMD in the drive.

Here's how:
Part 1:
(0. Ensure you have ISOs of both Clazziquai Edition and the Korean Version of Black Square on your PSP)
1. Make sure you have a PSP on 6.60 or 6.61, running Pro CFW
2. Set your UMD driver in the menu accessed with the SELECT button to Sony NP9660
3. Download the zip file from http://www1.axfc.net/uploader/so/2347109
4. Rename isochange.prx to anything without iso in it (I picked gamechange.prx)
5. Put the prx file into your PSP's SEPLUGINS folder (create one if you haven't already)

Part 2:
6. Create/Edit the text file 'game.txt' in your SEPLUGINS folder, and add this text, without quotes, as a new line: "ms0:/seplugins/isochange.prx 1" (if you're using a PSP Go, you might need to swap ms0 for ef0)
7. Rename Black Square's ISO to Disc1.iso, and Clazziquai's to Disc2.iso
8. Restart your PSP and re-enter Pro CFW

Part 3:
9. Open Black Square on your PSP, and select Link Disc
10. Get to the menu where you're required to Link with Clazziquai edition ("Please insert the Clazziquai UMD"). You may have to wait for the game to install the link disc files on your first attempt.
11. Open the HOME menu with the PS button, and press L, R, and START simultaneously. The PSP screen will turn black, and enter sleep mode.
12. After waiting 5 seconds, exit sleep mode by sliding the power switch up; Link Disc will initialize.
(13. When returning to Black Square, repeat the process of opening the HOME menu, etc. on the Black Square swap screen)

[Make sure to replace the name isochange.prx in step 6 with the name of your renamed prx file]