had a number of them. Thus the low-end systems could support a maximum of 10 MB of online storage (two fixed, two removable), although in practice this was very expensive and not common. The System/3 was also available with the IBM 5445 disk drive (20mb) and later the model 15 allowed "winchester" style 3340 drives. On the smaller models, while you could attach 5445 drives, you had to keep the 5444 for the operating system and other programming libraries, however that limitation was changed with software called elimn8 which allowed 5445 drives to totally replace the 5444's. Other companies such as Memorex manufactured compatible 5445 drives for the System/3. Multi-Function Card Unit The most common punched-card device was IBM 5424 Multifunction Card Unit (MFCU) which read, punched, printed on and sorted the new, smaller 96-column punched cards. Instead of the rectangular punches in the classic 80-column IBM card, the new cards had tiny (1 mm), circular holes much like paper tape. Data was stored in six-bit binary-coded decimal code, with three rows of 32 characters each, or in 8-bit EBCDIC, with the two extra holes located in the top rows. The new cards had room for 128 printed characters in four rows of 32 characters each. They were about 1/3 the size of the older 80 column cards but held 20% more text data. The smaller, and thus lighter card could be processed with faster equipment and with fewer jams. Available as RPQs (special order equipment) to handle 80-column cards were the IBM 2560 Multifunction Card Machine (MFCM) which could read, punch, interpret and sort, and the IBM 1442 which could only read and punch. Magnetic tape Offline storage was available with the purchase of an external tape drive which read and wrote standard IBM 9 track tape. The System/3 Mod 10 optionally included the IBM 3410 magnetic tape subsystem. Operator Console Facility The System/3 Operator Console Facility (OCF) consisted of either a modified IBM Selectric typewriter interfaced into the computer, or a special purpose IBM 3270 display. Within the OCF, there was capability to 'cancel' processes and/or tasks that were running, including either partition (P1 or P2). The system could only run two programs simultaneously, except for the model 15 or systems running the Communications Control program, CCP. The CCP was a system control programming feature that allowed to support an online network of terminals. Printers A smaller (IBM