NEC Floppy Disc Jumper Settings =============================== FD 1054 360kB FD 1155 -514 FD 1157C 1.2 MB FD 1037A 720kB FD 1137H 1.44MB FD 1138H 1.44MB FD 5037A 720kB FD 5137H 1.44MB FD 5138H 1.44MB All of this comes from a very diffuse document faxed to me from Nec support some 10 years ago. I have not left out any information even if I do not understand all of it myself. The coloured wire on a floppy cable shold always be used for pin 1. On a 5.25-drive connector pin 1 is the side closest to the key-slice. On a 3.5-drive you can look on the soldering where pin 1 should have a square soldering point while all the other are round. FD1054 360kB ------------ These drives are compatible with standard Floppy interface. Configuration 1: Non-twisted cable Computer USE MON VC M1 DCG LM0 LM1 DX XT 2 1 On On 1 0 1 see note AT 2 1 On On 2 0 1 see note note: Drive 1 (A:) has DX=0, drive 2 (B:) has DX=1 Configuration 2: Twisted cable (pin 10-16 twisted), Drive 2 and controller are on one the same side of the twist, and drive 1 is on the other side. Computer USE MON VC M1 DCG LM0 LM1 DX XT 2 3 On On 1 0 1 see note AT 2 3 On On 2 0 1 see note note: Both drive 1 (A:) and drive 2 (B:) has DX=1 My note: The original document had a very unclear layout and it is possible that the MON values should be interchanged, so that configuration 1 is MON=3 and configuration 2 is MON=1 instead. FD1157C 1.2 MB ---------------- These drives are compatibel with standard Floppy interface. Configuration 1: Non-twisted cable USE MON VC HDE DEN M1 DCG LM1 LM2 DX 2 1 On 1 1 On 2 0 0 see note note: Drive 1 (A:) has DX=0, drive 2 (B:) has DX=1 Configuration 2: Twisted cable (pin 10-16 twisted), Drive 2 and controller are on one the same side of the twist, and drive 1 is on the other side. USE MON VC HDE DEN M1 DCG LM1 LM2 DX 2 3 On 1 1 On 2 0 0 1 note: Both drive 1 (A:) and drive 2 (B:) has DX=1 FD1037A 720kB FD1137H 1.44MB FD1138H 1.44MB FD5037A 720kB FD5137H 1.44MB FD5138H 1.44MB --------------- These drives are compatible with standard Floppy interface. Twisted or non-twisted cable can be used. When using a twisted cable both drive 1 (A:) and drive 2 (B:) should have the DX jumper in position 1. When using a non-twisted cable drive 1 (A:) should have DX=0 and drive 2 (B:) shold have DX=1. A twisted cable has pin 10-16 twisted, drive 2 and controller on the same side of the twist, and drive 1 is on the other side. My note: FD5037A, FD5137H and FD5138H might be mounted on an adapter thing to fit in a 5.25"-slot, and the DX jumper may in that case be located on the adapter thing and not on the actual 3.5"-drive. FD1155-514 ---------- My note: Yes, the tables (1)..(4) really looks like this. I have checked and double-checked my typing since some of it lookes a little illogical, at least to me. (1) Head Load Condition HS USE Drive select & head load 1 1 Drive select 1 2 Head load 2 1 Drive select & motor on 1 3 Motor on 2 3 * (2) Motor On Condition MON Drive select 3 Head load 2 Motor on 1 * (3) Display Lamp Contidion IUS USC LED Head load 2 1 1 and 4 Head load & Drive select 2 1 1 and 5 Drive select - 2 and 4 Ready - 3 and 4 Ready & Drive select - 3 and 5 Drive select - 2 and 5 Head load 1 - 1 and 4 Head load & Drive select 1 - 1 and 5 * Note: "-" indicates that the plug position is allowed mounting on any position. (4) Density Switching Record High/Normal Plug position density density signal DEN High H level 1 * Normal L level Normal H level 2 High L level High H level 3 High L level High H level Open Normal L level (5) Rotation Change Rotation in a normal density mode HDE 360rmp ("single speed mode") 1 * 300rmp ("dual speed mode") 2 Note: A rotation in a high-density mode is 360 rpm for both short plug "HED"=1 and 2. (6) Disk Change/Ready Disk change/ready signal output condition DCG Ready signal 1 Disk change signal 2 * Option Plug Position On PWB: .---. | | | | | | | `--. | | | | `-. `---. .---. _| #IOS | | | �= #DX | ----------� | | `------------� | | ## MON## ##HS ## | | DCG ## DEN | | HDE## LED | `-. ____ _ | `--� `-----------------� `--------� /Tomas Andersson, January 2001.