IBM GA21-9236-1 IBM System-3 Model 8 10 12 15 Components Reference Manual Nov77 free download

File name GA21-9236-1_IBM_System-3_Model_8_10_12_15_Components_Reference_Manual_Nov77.pdf

pageof GA21-9236_l lssued March1980 28 By TNL: cN2t-0325 Chapter7. Disk StorageDrives IBM 54M15448 Disk Storage Drives o System/3Model 15A One ModelA2 }IBM5444DISKSToRAGE DRIVE Two Model A2s One ModelA2 and one ModelA3 Thef BM5444DiskStorage Driveprovides2,457,60O through9,830,400 bytesof storage. R E M O V A B L E I S KC A R T R I D G E S O R5 4 4 4 D F The5444isavailable sixmodels: in Tracks/ No. of Total Capacity Avg Access I (in bytes) Model Surface Disks2 Time 1 104 2 2,457,600 1 5 3m s A1 't04 2 2,457,600 86 ms 2 204 2 4.915,200 269 ms A2 204 2 4,915,200 1 2 6m s 3 204 'l 2,4s7,600 269 ms A3 204 2,457,600 1 2 6m s I I B M r e s i d e n tc o n t r o l p r o g r a m r e q u i r e so n e t r a c k p e r s u r f a c e f o r c u s t o m e r e n g i n e e r s . I B M d i s k s y s t e m sp r o g r a m m i n g s u p p o r t r e q u i r e s3 t r a c k s p e r s u r f a c ef o r a l t e r n a t ed a t a t r a c k s . S y s t e m su s i n g t h e s e p r o g r a m sa r e t h e r e f o r e l i m i t e d t o 10 0 o r 2 0 0 t r a c k s p e r s u r f a c e ,a c c o r d i n gt o t h e m o d e l selected. 2 E a c h m o d e