Panasonic JB-3300 Technical Manual page 398

1.4 Block Diagram
This LSI handles signal exchange between the IBM personal computer's
I/O channel and the NDC 841 LSI.
(2) NDC 842
This LSI changes MFM data sent from the disk drive into NRZ data,
Changes NRZ data from the host computer into MFM data, and executes
read and write operations vis-a-vis the disk drive.
(3) NDC 841
This LSI converts signals between the controller and the NDC 843 LSI
for the IBM I/O channel.
(4) NDC 840
This LSI operates in the HDC according to commands sent from the MPU
(Z80). It converts 8-bit parallel data sent by the host computer into
serial data and also converts serial data sent by the disk drive into
8-bit parallel data. During write operation, it adds a 4-byte ECC to
the end of the write data and, during read operation, it checks this
pattern for read errors and corrects any errors detected (using an 1l1-
bit burst). |
VII - 3