San Francisco will phase out the use of obsolete 5.25-inch floppy disks in the subway

San Francisco (USA) is allocating $212 million to replace its outdated subway control system using floppy disks. The total modernization investment will be $700 million, of which $488 million will go to replacing old and slow communications cables and other important purposes.

Image source: Hosein Zanbori/Unsplash

This is not the first time that government organizations have abandoned the use of floppy disks in favor of modern technologies. For example, last year similar initiatives were taken in Germany and Japan. SFMTA officials previously said the system was introduced “in an era when computers did not have hard drives and that the technology was time to change.” Notably, Muni Metro uses 5.25-inch floppy disks, which were popular in the 1980s, rather than the more common 3.5-inch or 8-inch formats.

Agency spokesman Michael Roccaforte explained the old system in an interview with Ars Technica: “When a train enters the subway, its on-board computer is connected to an automatic control system, in which drivers can only observe the movement. When exiting the subway, train control returns to manual mode.” However, such a system is outdated and requires replacement, as it does not meet modern safety and efficiency standards.

Additionally, current communications cables have proven to be extremely fragile and slow. According to Roccaforte, their bandwidth is “less than an old AOL modem.” Therefore, to increase the reliability and speed of the system, it is necessary to upgrade not only the disk drives, but also all cable networks.

The full upgrade of Muni Metro is expected to be completed by 2033-2034. However, shorter-term tasks such as replacing cables and floppy disks are scheduled to be completed by 2027-2028. This deadline coincides with the previously stated goal of completing floppy replacement by 2028.