The Philips C7420 was an expansion for the Philips Videopac gaming console. It consists in a second CPU (Z80), extra memory and a Microsoft BASIC interpreter.
zcc +c7420 -create-app program.c
This will genetrate a file, _a.bas, (a binary tape image) suitable for the O2EM emulator or for the BASIC.JAR tool (a Java VM is required in this latter case). The file name can be varied with the '-o' option, and can be loaded with the command CLOAD “_a” (or similar).
zcc +c7420-create-app -zorg=<location> program.c
This is a further experimental mode, meant to create two cassette block files, a BASIC loader (i.e. _a.bas) and a block created in “CSAVEM” mode (i.e. a.bas); it is untested and probably not fully working.
The o2em emulator needs to be invoked with the proper parameter to enable the BASIC extension cartridge:
To boot the cartridge, at the splash startup screen, press '0', then use the “CLOAD” command as already explained.
The programs must be put in the “/basic” subfolder.
The unofficial C7420 emulator at 'guttenbrunner.com' … hidden around here O2EM 1.20 Beta 5.