Changes
/* Sound */
Amstrad then improved the build quality and enhanced the Spectrum's design. The result was that the Spectrum +2, which was closer in looks and build to the CPC464/6128 (same kind of compact keyboard as CPC6128, but built-in "Datacorder"). The Spectrum +3 was also quite similar to the Amstrad CPC6128 because both had a internal 3" drive. So the Spectrum became closer in design to the CPC. However, the overall hardware of the Spectrum didn't change, the graphics were the same, the sound was the same, but those later Spectrum's had built in joysticks, built in cassette or disc, connections for printer etc, just like the CPC, but almost all of which the Amstrad had starting with the CPC464.
====Disc drive===
The Spectrum didn't have an official floppy disc interface so there were different interfaces.
In Russia the Betadisk interface is common, this used a WD1793 disc controller and 3.5" discs. This interface is incompatible with the Amstrad's.
When Amstrad designed the +3, the used a similar disc interface to the Amstrad.
The Amstrad designed Spectrum +3 has the following in common with the CPC6128:
* same disc media (3")
* same disc controller (NEC765 compatible)
* the floppy controller is polled for data transfer
* Similar disc format (CP/M based)
===Consequences of a Spectrum Port===
