The M4 Board is a 2016 expansion card which enables WIFI access to and from CPC and using SD-Card as mass storage.
You can read more about it at http://www.spinpoint.org/cpc/m4info.txt.
M4 Front View
M4 Back View
Firmware
| Version | File |
|---|---|
| 1.01 | M4FIRM_v101.zip |
| 1.02 | M4FIRM_v102.zip |
| 1.03 | M4FIRM_v103.zip |
| 1.04 | M4FIRM_v104.zip |
| 1.05 | M4FIRM_v105.zip |
| 1.06 | M4FIRM_v106.zip |
| 1.07 | M4FIRM_v107.zip |
| 1.08 beta | M4FIRM_v108b.zip |