SR_EXT
out_8(&via[ACR], (in_8(&via[ACR]) & ~SR_CTRL) | SR_EXT); /* SR data in */
via[ACR] = (via[ACR] & ~SR_CTRL) | SR_EXT;
out_8(&via1[ACR], in_8(&via1[ACR]) | SR_OUT | SR_EXT);
out_8(&via1[ACR], (in_8(&via1[ACR]) & ~SR_OUT) | SR_EXT);
via1[ACR] |= SR_OUT | SR_EXT; eieio();
via1[ACR] = (via1[ACR] & ~SR_OUT) | SR_EXT; eieio();