|  
 IBM 3430 Magnetic Tape 
                        Subsystem 
                          Announced March 15, 1983 and withdrawn December 
                          19, 1989  The 3430 was a dual density, 50 inch-per-second tape 
                        drive. It read or wrote either 1600 bytes-per-inch phase 
                        encoded (PE) or 6250 bytes-per-inch group coded 
                        recording (GCR). The GCR mode provided more efficient 
                        detection and correction of tape read errors while the 
                        PE mode provided compatibility with and conversion of 
                        existing 1600 BPI tape files. GCR also provided a 
                        greater tape density (6250 BPI), which improved 
                        performance up to 312K bytes per second.  Two models were available in the 1980s: 
                          Model A01, which consisted of the subsystem 
                          control unit and one tape unit housed in the same 
                          frame.
 
Model B01, which was a tape unit only.  Three Model B01s could be attached to a Model A01 for 
                        a maximum of four tape units per subsystem. The 3430 Subsystem was compatible with existing tape 
                        subsystems and could be attached to the following host 
                        processors: Some of the advantages provided by the 3430: 
                          Read and wrote data at lower costs than previous 
                          IBM tape subsystems with similar recording 
                          capabilities.
 
Large-scale integration circuitry permitted 
                          reliable subsystem operations at low cost, with fewer 
                          and more condensed printed circuit cards.
 
Compact size provided users with increased space 
                          savings. Horizontal tape transport deck permitted easy 
                          tape reel mounting and handling.
 
Error correction and improved maintenance 
                          functions designed into the system increased 
                          productivity and reliability.  The side panels were offered in the following colors: 
                        pebble gray, garnet rose, classic blue, willow green, 
                        charcoal brown and sunrise yellow. The 3430 was developed and manufactured at the IBM 
                        General Products Division facility in Tucson, 
                        Arizona. Technical Summary 
                          
                          
                            | 
                                
                                
                                | Model 
                                A | Tape 
                                drive/controller |  
                                | Model 
                                B | Second, third 
                                and fourth drives in 
                                string |  |  
 
                          
                          * Difference in gap size did not prevent 
                        tape interchange with IBM 3420 tape drives.
                            | 
                                
                                
                                |  | GCR | PE |  
                                | Density, 
                                BPI | 6,250 | 1,600 |  
                                | Instantaneous data rate, KB/S | 312 | 80 |  
                                | Tape 
                                speed, IPS | 50 | 50 |  
                                | Maximum 
                                tape length, feet | 2,400 | 2,400 |  
                                | Capacity 
                                MB (block=16KB)
 | 152 | 43 |  
                                | Rewind 
                                time (2,400'), minutes
 | 2.7 | 2.7 |  
                                | Interblock Gap*, inches | .45 | .60 |  
                                | Read/Write access time, ms | 6 | 6 |  |  |