Heyoop,
The VE-JV1 has 512 patches, as the brochure says.
The misunderstanding is that the A70 access directly PERFORMANCES, and not PATCHES.
A performance is made by up to 4 patches, layered or splited (zone A,B,C,D internal).
You have 64 internal performances, but the keyboard can access up to 128 performances if you use the External M-512 RAM card, so if you set for a performance grater than 64 without the RAM card you will have a message "No RAM card present".
To ear the 512 patches, you may select a performance (anyone), let just one zone on and change the parameters PROG CHG (program change - last row left side button) and Bank select (last row second left button).
I'm not in front of the keyboard, but the bank select may be 81 (MSB) and 0,1,2,3 for the (LSB)(look on the brochure). You will have 128 patches x 4 banks = 512 total patches. Some of them are repeated.