Below is a french do it yourself project for connecting a SP0256 speech chip to a printer port, using Data, Strobe=ALD, and Ack=Status.
It isn't actually a CPC project (for the CPC one would need to replace LPRINT by PRINT #8) (and the CPC's printer port has only a Busy pin, no Ack pin), aside from that, it should be compatible with the CPC printer port (the CPC's GNDed D7 printer bit is no problem, since allophone numbers are only 6bit wide).
- SP0256 on Printer Port (DIY) (French)
No idea what the 74374 latch is intended for, the printer port output should be latched anyways, so it seems to be totally useless. Using SBY (instead of LRQ) means that software can't use the "1-byte FIFO" of the SP0256, which is no good (the reason for that poor design was probably that LRQ would need to be inverted by additional hardware before passing it to ACK).