In 1986, Acorn introduced a new range of Econet fileservers which were a development from the earlier Level 2 and Level 3 FileServers. These were known as FileStores and they are distinct from previous fileservers because they are standalone machines which plug into the network. They are not expanded BBC micros running fileserver software. Each of the FileStores comes with identical casing which is very similar to the drive unit of the BBC Master Compact.

The FileStore E01 is an Econet station in its own right which acts as a fileserver when connected to a network. It is a single unit which does not require a monitor or keyboard. Communication with the FileStore is done via another Econet station when the FileStore is in one of two "maintenance modes"

The E01 can be seen as a slimmed-down BBC computer tailored for its function as a fileserver. It has a 6502 processor at its heart along with a 6522 VIA just like the BBC. It requires a Master series Econet module to be plugged in and connects to the network via an Econet port in the same way as any other station.

Two 3½" floppy drives are provided which give just under 1.2MB of storage space available to users.

As an expansion option, the FileStore E01 has a 1 MHz bus port at the back for connecting a FileStore E20 unit. In theory, any BBC-compatible hard disc ought to be able to be attached to a FileStore.

A parallel printer port is also provided, allowing the FileStore to act as printer server as well as file server.

The FileStore can generate its own clock which is suitable for short networks of a few machines.

Running the show is an MOS ROM and a fileserver ROM. The FileStore has 64K of RAM and the contents of the ROMs are copied into the RAM on start-up. The software is again based very much on existing BBC protocol with the FileStore being able to accept certain OSBYTE and OSWORD calls.

Access to the floppy drives is protected by a drive door. If the flap is opened, the FileStore enters maintenance mode. Any data held in memory is ensured to the floppy discs in case the discs are removed. At this point, the network will stop functioning and all users will be logged off when the FileStore returns to user mode.

The FileStore can be put into maintenance mode via software, using the *FSMODE command given by a privileged user. I find this very handy because my FileStore is shut away in a glass-fronted cabinet and it would be near impossible to get at the thing to open the drive door.

As well as a network clock, the FileStore also has a real-time clock which is used to date-stamp files. However, the FileStore continues in the earlier tradition of Acorn fileservers in being unable to count beyond 1996. This is because the year is stored as four bits. In four bits, the range of numbers which can be stored is from 0 to 15. The year number is taken as being an offset from 1981 so the maximum year is 1981+15 = 1996.

The clock is battery-backed, as is the CMOS RAM which stores configuration settings such as the FileStore's station number, printer server number and the maintenance user name and password. This is provided because the FileStore will start up in maintenance mode if the drive door is open when the unit is switched on. The obvious security fear here is that somebody could open the drive door, turn on the FileStore and do a *FSFORMAT or other disastrous commands. To stop this, a user must log on to the FileStore in maintenance mode using the user name and password held in CMOS RAM.

The FileStore E01 has a fan, which is presumably to cool the power supply. I find this a bit pointless really since the BBC micros do not have a fan to cool their power supplies. The fan on the FileStore is extremely noisy too! I suppose the thinking is that the FileStore would be permanently switched on to service a network at any time of the day.

My FileStore E01 is a crucial part of my Econet as it is my main network fileserver, although I do have other servers available if I need them. It has done sterling work since I got it in September 2002.

The E01S - the "S" standing for "Stacking" - is a later version of the original FileStore E01. The most visible difference is that at the back is a 50-way "D" type connector as an expansion port for the FileStore E40 and E60. As far as I know, the E20 is not suitable for the FileStore E01S.

Inside the E01S, the two software ROMs are replaced with a combined MOS/fileserver ROM.

The E01S is reportedly able to deal with dates after 1996 although I am unable to verify this.

The FileStore E20 is the first of three hard disc units designed by Acorn for use with the FileStore base units.

The E20 is a 20MB hard disc unit which plugs into the back of the FileStore E01. It must be connected to the E01 for use on the network as there is no processor circuitry to enable it to be used on its own.

Inside the E20 is a power supply, fan, hard disc with on-board Winchester disc controller and host adapter. The drive is a Rodime RO652 which provides 20MB of space when formatted for Econet use, although you can get 28MB out of it if it is formatted directly for use on a BBC.

There are two 37-way D-type ports at the back of the E20 to enable the unit to be connected to a FileStore E01 and to a second E20. I think for this setup, only 2 E20 units can be chained behind an E01.

I use my FileStore E20 to back up my Technomatic Winchester disc.

The E40S is a 40MB hard disc unit for use with the Stacking FileStore E01S. It connects via a 50-way cable to the back of the E01S and may be part of a chain of up to 4 E40 or E60 devices.

This the final machine in the FileStore range providing 60MB of hard disc space. I think when the FileStores were first introduced, this would have been quite a phenomenally large amount of space! If four E60s were connected to an E01S, then 240MB would have been a mind-blowing level of storage!