The '''DMP3250di''' is basically the same as the [[DMP3160]], but with Dual Interface (as indicated by the "di" suffix) (with additional RS232 connector). Aside from the suffix, Amstrad did (for whatever reason) also change the model number from 3160 to 3250 - although the technical specs seem to be more less unchanged. Namely, like the DMP3160, the DMP3250di supports only 160 chars/second (not 250).
Some details that are different: Adding the RS232 port may have required a new PCB (unless the DMP3160 board was prepared for RS232 expansion), accordingly the printer BIOS must contain RS232 support. The case needs a new opening for the RS232 connector. Another small difference is that the metal stands are arranged differently (the DMP3160 and older models had their "feet" on left & right side, the DMP3250di has them at front & rear side). And, the transparent plastic cover is bigger (resemple resembles more the CPC-style DMP2000/DMP2160 models than the PC/PCW-style DMP3000/DMP3160 ones).
The printer is mainly intended for use with PC/PCWs, the gray color is't matched to the design of the CPC, and the RS232 input would be fairly useless for CPCs (except as an overcomplicated way for bypassing the CPC's 7bit [[Printer Port]] limit).