DFIFO_REG
NCR_700_writeb(CLR_FIFO, host, DFIFO_REG);
NCR_700_writeb(FLUSH_DMA_FIFO, host, DFIFO_REG);
NCR_700_writeb(0, host, DFIFO_REG);
count = ((NCR_700_readb(host, DFIFO_REG) & 0x7f) -
count = ((NCR_700_readb(host, DFIFO_REG) & 0x3f) -