[[Image:Burning Rubber - cara A.jpg|right|thumb|250px|A cartridge for the + series]]
A cartridge system was introduced with the launch of the CPC+ [[Plus]] and GX4000 series. This enabled developers to distribute games via cartridges on the new Amstrad. The cartridges are protected with the [[ACID]] chip.
== EPROMs ==
All known manufactured cartridges contain EPROMs (rather than PROMs or ROMs). The cartridges can be fitted with different EPROMs in range of 32K 32kb through 512K (actually produced are 512kb, but only 128K..256K)128kb to 256kb versions are known to have been produced. The cartridge PCBs typically include six [[LK Links]] to match the PCB to the EPROM pin-outs:
VCC ---LK1--- EPROM.A18 ---LK2--- CA18
VCC ---LK3--- EPROM.A17 ---LK4--- CA17
== Protection ==
The EPROMs aren't encrypted, making it very easy to dump their content, or to replace them by other EPROMs. However, all cartridges must contain an '''[[ACID''' ]] chip, otherwise the CPC+[[Plus]]/GX4000 refuses to work, meaning that unlicensed third-party developers couldn't produce cartridges without buying the ACID hardware from Amstrad. * For details on the chip, see [[ACID]]hardware from Amstrad.
== Pictures ==
Amstrad released a Demonstration system for his retailer in order to show GX4000 games: the [[Amstrad CSD]] (Cartridge Software Demonstrator).
It was a 464plus 464 [[Plus]] motherboard, with an extra "daughter board) " allowing the insertion of 12 games cartridges, plus an extra special cartridge acting as an OS.
<gallery caption="Some photos of Amstrad Expo 90">