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SJ Research MDFS

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Introduction

The SJ Research MDFS (Modular Disc File Server) is widely regarded as the best Econet file server. Major features included its reliability, performance and flexibility. The MDFS could support up to 4 SCSI hard discs, 4 floppy discs, tape cartridge drive and 2 printers. SJ Research made matching expansion cases for floppy discs, hard discs and tape drives (see the MDFS brochures). However my MDFS (see first picture) has just 1 Watford Electronics SCSI disc attached. The disc is a Rodime 43MB RO3057S.

The MDFS configuration is:

The MDFS automatically date and time stamps files when saved or updated and supports disc space accounting which allows disc space limits to be set for each user. The MDFS can support up to 80 logged-on users. In 1986 an MDFS with 20MB hard disc and tape streamer would have cost you £3,600 as an educational user.

Documents

 Here is a brochure describing the SJ Research MDFS. 
Here is a more detailed brochure MDFS The most advanced File Server for Econet 

MDFS

SJResearch MDFS with Watford SCSI Disc 

SJ Research MDFS with Watford SCSI Drive

SJResearch MDFS front 

SJ Research MDFS (front)

The picture shows the front of the MDFS. From the left to right are the controls and indicator LEDs: Release discs button, Discs Free LED, Utility Mode LED, Parallel printing LED, Serial Printing LED, No Clock LED, System Error LED, power LED, Online LED and the mode change lock.

 SJResearch MDFS back

SJ Research MDFS (back) 

The picture shows the back of the MDFS. From the left to right: Fuse and power lead, Expansion box power connector, 2 BBC floppy disc drive power connectors, Econet socket, RS232 serial port, parallel printer port, 2 floppy disc drive connectors (Drives A&B and Drives C&D) and SCSI bus Interface.

 SJResearch MDFS open

 SJ Research MDFS with cover off

The picture shows the MDFS with the top cover off, but is better seen in the next picture. Here is a HiRes picture of the inside of an MDFS. 

SJResearch MDFS circuit boad 

SJ Research MDFS circuit board

MDFS Tape Drive

 SJR MDFS Stacked with tape drive front

SJ Research MDFS Stacked with Tape Drive (front)

This picture shows an SJ Research MDFS on top of the Tape Drive expansion.

SJR MDFS stacked with tape drive back 

SJ Research MDFS Stacked with Tape Drive (back)

The back of the SJ Research MDFS Tape Drive showing the power cable plugged into one of the MDFS auxillary power sockets and the SCSI cable plugged into the SCSI socket.

SJR MDFS Tape Drive front

SJ Research MDFS Tape Drive (front) 

The front of the SJ Research MDFS Tape Drive showing the slot the tape cartridge is inserted in.

SJR MDFS Tape drive back 

SJ Research MDFS Tape Drive (back)

The back of the SJ Research MDFS Tape Drive showing the power cable, the SCSI ribbon cable and the serial number which is MDFS/532.

 SJR MDFS Tape Drive bottom

SJ Research MDFS Tape Drive (bottom)

 SJR MDFS Tape drive open

SJ Research MDFS Tape Drive with top cover removed

Inside the SJ Research MDFS Tape Drive showing the 3M tape drive, and a lot of empty space.

SJR MDFS Tape drive right 

SJ Research MDFS Tape Drive (right side)  

I am not sure what the model the tape drive is, I think it uses a DC2120 tape cartridge but can't be certain. If so it would allow 2 MDFS Disc partitions (59MB) to beacked up onto a single DC2120 tape.