74LS367
Parts Z14, 15, 16, 17, 18. are tri-state buffers.

Z15 and Z16 are display RAM buffers they allow the CPU to address the video display RAM.

Five of these chips are used in total.

One is used in the Ace.
The one in this image runs at 6.5536 Mhz, which would give a 3.2768Mhz Clock speed for the Z80A CPU

3.5 Mono Jack sockets.
3 are used in the Ace.
Uses for the Tape Input/Out ports on the Ace.


Also as the Power Input [See here for 3.5 Power details]