That firmware was for an MP4 with horizontal 2.0" display, this one:
http://www.popchip.cn/ProductShow.as...BB%8B%E7%BB%8D
But since it was able to control yours, your display probably has a similar family of controller and the connectivity is also the same.
From that partially working firmware we can find the information about your player:
LCM reset: GPIO B4
LCM command/data: GPIO B5
Backlight: GPO A2
Display controller type: PCF8833 compatible family, 1-byte addresses -- possible matches are LDS172/LDS176/LDS183/ST7637.
How I found out:
http://wiki.s1mp3.org/LCMControllerDetection
http://wiki.s1mp3.org/LCMControllers
Since you have a Popchip player, go to manufacturer site and find the closest matching model of
ping guo er dai from here:
http://www.popchip.cn/Product.asp?Bi...20027;控
Then find a firmware for that model and try it. It seems many of them share common connectivity and display type.