When it downloads by a Mac, a file may be occasionally changed into a text file.
For example, the file of downloaded OS2XL will be changed into "mpc1000_xl361.os2.txt."
In this case, if it corrects to right file name"mpc1000_xl361.os2", it can load by MPC.
 
Name Version

File name

Size Available Upload day
Free 3.16 mpc1000_jv316.bin 734KB Download Feb 16, 2015
Please install OS2XL from the load screen of free JJ OS Ver.3.16.
OS2XL 3.61 mpc1000_xl361.os2 1353KB Download Sep 02, 2019
Please install OS3 from the load mode of free Ver.3.16 or OS2XL
For dual boot users, please install OS1 Ver.5.00 first
OS3 2.32 mpc1000_jv232.os3 1202KB Download May 08, 2019
OS3 1.52 mpc1000_jv152.os3 1213KB Download Jan 24, 2017

When not downloadable, it is here.

OS only for large LCD (240X128)
OS128XL is installable only from OS128 bundled with large LCD.
Name Version

File name

Size Available Upload day
OS128XL 2.31 mpc1000_128xl231.osl 1334KB Download May 08, 2019
OS128XL 1.81 mpc1000_128xl181.osl 1316KB Download Jan 24, 2017
OS only for large LCD (240X128)
OS128SP is installable only from OS128ORG or OS128XL.
OS128SP 1.11 mpc1000_128sp111.osl 1349KB Download Aug 01, 2017

Large LCD can be purchased from mpcstuff.com.