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External floppy drives on the Spectrum +3

384 bytes added, 16:12, 14 December 2015
link to cable construction guide
====The +3 External Drive Connector====
The ''"Disk B:"'' connector on the +3 is slightly non standard and there is an error in the manual which adds to the confusion. The connector is rotated through 180 degrees so pin 1 is at the top right rather than the bottom left (looking in from the rear of the computer). The indexing slot is also at the opposite end to normal, instead between pins 31/32 and 33/34, this means that a keyed any standard PC floppy cable will only fit in the '''wrong''' orientation unless the polarising key is (re)moved.
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====Connecting a modern 3½″ FDD====
=====Cable=====
[[File:Spectrum_plus3_external_floppy_drive_cablespectrum_plus3_external_floppy_drive_cable.jpgpng|thumb|An example of a suitable cable]][[File:Spectrum_plus3_external_floppy_drive_cable_detail.jpg|thumb|Using a toggle switch to apply the Ready signal]]
To connect a normal PC floppy drive as "drive B:" to the +3 you need a 34 way ribbon cable with an IDC card edge connector at one end, and an IDC socket connector at the other.
Modern floppy drives don't provide the drive ready signal, so the {{overline|READY}} line needs shorting to ground to signal to the Spectrum that the drive is ready (adding a . A switch here so you can be used to manually toggle the ready signal on and off , but a more convenient method is to place a good idea otherwise diode between the {{overline|READY}} and {{overline|DRIVE 1}} lines so that the ready signal is exerted whenever the external drive is accessed. Wiring the {{overline|READY}} permanently to ground works, but is not recommended as this causes the Spectrum won't start up unless there's a disk loader to hang when no diskette is present in the internal drive), meaning that loading tape software from the loader option on the boot menu is impossibleA detailed guide to constructing a suitable cable is available [http://zxnet.co.uk/spectrum/plus3_external_floppy_cable/ here]
=====Drive=====

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