Difference between revisions of "External floppy drives on the Spectrum +3"

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[[category:hardware]]
+
====The +3 External Drive Connector====
[[category:spectrum]]
+
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 any standard PC floppy cable will only fit in the '''wrong''' orientation unless the polarising key is (re)moved.
====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 floppy cable will only fit in the '''wrong''' orientation unless the key is (re)moved.
 
  
 
{| class="wikitable" style="text-align: center;"
 
{| class="wikitable" style="text-align: center;"
 
|+ External drive connector pinout (viewed from rear of computer)
 
|+ External drive connector pinout (viewed from rear of computer)
 
|- style="font-size: 70%;"
 
|- style="font-size: 70%;"
! style="width: 5em;" | 33  
+
! style="width: 6em;" | 33  
! style="width: 5em; border-width: 1px 4px 1px 1px; border-right-style: double;" | 31  
+
! style="width: 6em; border-width: 1px 4px 1px 1px; border-right-style: double;" | 31  
! style="width: 5em;" | 29
+
! style="width: 6em;" | 29
! style="width: 5em;" | 27
+
! style="width: 6em;" | 27
! style="width: 5em;" | 25
+
! style="width: 6em;" | 25
! style="width: 5em;" | 23
+
! style="width: 6em;" | 23
! style="width: 5em;" | 21
+
! style="width: 6em;" | 21
! style="width: 5em;" | 19
+
! style="width: 6em;" | 19
! style="width: 5em;" | 17
+
! style="width: 6em;" | 17
! style="width: 5em;" | 15
+
! style="width: 6em;" | 15
! style="width: 5em;" | 13
+
! style="width: 6em;" | 13
! style="width: 5em;" | 11
+
! style="width: 6em;" | 11
! style="width: 5em;" | 9
+
! style="width: 6em;" | 9
! style="width: 5em;" | 7
+
! style="width: 6em;" | 7
! style="width: 5em;" | 5
+
! style="width: 6em;" | 5
! style="width: 5em;" | 3
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! style="width: 6em;" | 3
! style="width: 5em;" | 1
+
! style="width: 6em;" | 1
 
|- style="font-size: 70%;"
 
|- style="font-size: 70%;"
 
| GND
 
| GND
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|-
 
|-
 
|}
 
|}
 +
====Connecting the Amstrad FD-1====
 +
The Amstrad FD-1 external FDD is an external drive manufactured for the Amstrad CPC range of computers. The unit is mains powered and contains a single sided 3″ drive like the one in the +3.
 +
The main thing to be aware of when using these units with the +3 is that they place a 5v supply on four of the pins (needed to power the DDI-1 disk interface for the CPC464). This could cause issues if the connector is reversed when connecting to the +3. The 5v can be disconnected inside the FD-1 by unplugging the 0.1″ latched connector from the small 34-26 pin ribbon adapter board at the rear of the unit.
  
====Cable====
+
====Connecting a modern 3½″ FDD====
[[File:Spectrum_plus3_external_floppy_drive_cable.jpg|thumb|An example of a suitable cable]]
+
=====Cable=====
[[File:Spectrum_plus3_external_floppy_drive_cable_detail.jpg|thumb|Using a toggle switch to apply the Ready signal]]
+
[[File:spectrum_plus3_external_floppy_drive_cable.png|thumb|An example of a suitable cable]]
To connect a normal PC floppy drive as "drive B:" to the +3 you need a ribbon cable with an edge connector at one end, and an IDC connector at the other.
+
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 old "Ready" signal, so the ready line needs shorting to ground to signal to the spectrum that the drive is ready (adding a switch here is a good idea otherwise the spectrum won't start up unless there's a disk in the drive).
+
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. A switch can be used to manually toggle the ready signal on and off, but a more convenient method is to place a 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 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 impossible.
  
====Drive====
+
A detailed guide to constructing a suitable cable is available [http://zxnet.co.uk/spectrum/plus3_external_floppy_cable/ here]
Any modern floppy drive will work as drive B: with the above proviso, you must create a ready signal for the spectrum otherwise it won't work.
+
 
 +
=====Drive=====
 +
Any modern 3½″ floppy drive will work as drive B: with the above proviso, you must create a ready signal for the Spectrum otherwise it won't work.
 
All modern drives are hard wired to appear as drive B: (hence the "twist" cable in a PC to make it appear as drive A:) so the cable is just a straight through wiring of all the signals.
 
All modern drives are hard wired to appear as drive B: (hence the "twist" cable in a PC to make it appear as drive A:) so the cable is just a straight through wiring of all the signals.
  
====Media====
+
=====Media=====
The +3 doesn't know about High Density (1.44MB) diskettes so you need to use Double Density (720K) ones, aka "blue floppies". These can be bought online, I don't know if they're still being manufactured anywhere or just new old stock. You can also cheat and tape over the hole on a HD diskette to make it appear as a DD one. This may or may not work, and the data may not stay forever (or it might be fine! but better safe than sorry if you save anything vaguely important on them). If you're just going to use a single diskette to "ferry" files from a PC to 3" disks then this is a perfectly adequate solution.  
+
The +3 doesn't know about High Density (1.44MB) diskettes so you need to use Double Density (720K) ones. You can also cheat and tape over the hole on a HD diskette to make it appear as a DD one. This may or may not work, and the data may only last weeks or days (or it might be fine! but better safe than sorry if you save anything vaguely important on them). If you're just going to use a single diskette to "ferry" files from a PC to 3″ disks then this is a perfectly adequate solution.
 +
 
 +
====Formatting====
 +
DSDD diskettes can be formatted as 720k DOS disks or with one of a variety of formats that the +3DOS can use.
 +
 
 +
=====+3DOS format disks=====
 +
3½″ disks can be formatted in a variety of different capacities as CP/M disks. The +3 ROM cannot format 3½″ disks itself so either a utility is required on the +3 (such as [http://www.worldofspectrum.org/zxplus3e/software.html#mformat The Spectrum +3 Multiformatter] by Garry Lancaster), or the disk must be prepared on the PC.
  
====Disk Images====
+
=====DOS format disks=====
There are various software tools to write DSK images to physical diskettes, and individual files to +3 formatted diskettes.
+
to access a DOS formatted 720k disk on the +3 you can use [http://www.worldofspectrum.org/zxplus3e/software.html#msdos Garry Lancaster's MSDOS utility]
The other option (if you just want to "ferry" files from the PC to the +3 and save them on drive A:) is to format the disks to 720k DOS format and use a tool on the +3 to copy the files from the DOS floppy to the +3 format floppy in drive A: (or to the ram disk and then back onto a +3 formatted 3.5" disk in B:)
+
This will allow you to "log on" to a DOS format disk in drive B: and copy files from it to a +3DOS formatted 3″ disk in drive A:
  
 
====Writing Images====
 
====Writing Images====
to access +3 formatted disks and format disks to this format on Windows NT you will need the [http://simonowen.com/fdrawcmd/ FDrawcmd driver by simon owen]. This will only work with real floppy drives, not USB floppy drives attached to laptops.
+
=====3½″ diskettes=====
A good utility for writing the images is [http://www.seasip.demon.co.uk/Unix/LibDsk/#tools John Elliot's dsktool].
+
To read and format disks with formats other than 720kB (the +3multiformatter utility refers to this as 708K) on Windows NT you will need the [http://simonowen.com/fdrawcmd/ FDrawcmd driver by simon owen]. This will only work correctly on PCs with real floppy controllers.
 +
A good utility for writing the images is [http://www.seasip.info/Unix/LibDsk/#tools John Elliot's dsktool].
 +
It's possible to read and write 708K +3DOS format dsk images using dsktool on some USB floppy drives that have an NEC UF000x chipset. The Dell FDDM-101 module is known to work.
 +
 
 +
=====3″ disks=====
 +
A guide to connecting a 3″ drive to a PC and reading/writing disks is available from the [http://www.worldofspectrum.org/sdp/FAQ.html Spectrum Disk Preservation Project]
  
 
====Writing individual files====
 
====Writing individual files====
 
To write individual files to a +3 formatted diskette (or dsk file) you can use [http://www.cpctech.org.uk/download/cpcxfs.zip cpcxfs]
 
To write individual files to a +3 formatted diskette (or dsk file) you can use [http://www.cpctech.org.uk/download/cpcxfs.zip cpcxfs]
  
====DOS format disks====
+
[[category:Hardware]]
to access a DOS formatted 720k disk on the +3 you can use [http://www.worldofspectrum.org/zxplus3e/software.html#msdos Garry Lancaster's MSDOS utility]
+
[[category:Spectrum]]
This will allow you to "log on" to a DOS format disk in drive B: and copy files from it to drive A:
+
[[Category:Floppy disk interfaces]]

Latest revision as of 12:16, 26 April 2017

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 any standard PC floppy cable will only fit in the wrong orientation unless the polarising key is (re)moved.

External drive connector pinout (viewed from rear of computer)
33 31 29 27 25 23 21 19 17 15 13 11 9 7 5 3 1
GND GND GND GND GND GND GND GND GND GND GND GND GND GND GND GND GND
READY HD_SEL RD WR_PROT TRACK0 WR_GATE WR_DATA STEP DIR_IN MTR_ON NC DRIVE1 NC INDEX NC NC NC
34 32 30 28 26 24 22 20 18 16 14 12 10 8 6 4 2

Connecting the Amstrad FD-1

The Amstrad FD-1 external FDD is an external drive manufactured for the Amstrad CPC range of computers. The unit is mains powered and contains a single sided 3″ drive like the one in the +3. The main thing to be aware of when using these units with the +3 is that they place a 5v supply on four of the pins (needed to power the DDI-1 disk interface for the CPC464). This could cause issues if the connector is reversed when connecting to the +3. The 5v can be disconnected inside the FD-1 by unplugging the 0.1″ latched connector from the small 34-26 pin ribbon adapter board at the rear of the unit.

Connecting a modern 3½″ FDD

Cable
An example of a suitable cable

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 READY line needs shorting to ground to signal to the Spectrum that the drive is ready. A switch can be used to manually toggle the ready signal on and off, but a more convenient method is to place a diode between the READY and DRIVE 1 lines so that the ready signal is exerted whenever the external drive is accessed. Wiring the READY permanently to ground works, but is not recommended as this causes the 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 impossible.

A detailed guide to constructing a suitable cable is available here

Drive

Any modern 3½″ floppy drive will work as drive B: with the above proviso, you must create a ready signal for the Spectrum otherwise it won't work. All modern drives are hard wired to appear as drive B: (hence the "twist" cable in a PC to make it appear as drive A:) so the cable is just a straight through wiring of all the signals.

Media

The +3 doesn't know about High Density (1.44MB) diskettes so you need to use Double Density (720K) ones. You can also cheat and tape over the hole on a HD diskette to make it appear as a DD one. This may or may not work, and the data may only last weeks or days (or it might be fine! but better safe than sorry if you save anything vaguely important on them). If you're just going to use a single diskette to "ferry" files from a PC to 3″ disks then this is a perfectly adequate solution.

Formatting

DSDD diskettes can be formatted as 720k DOS disks or with one of a variety of formats that the +3DOS can use.

+3DOS format disks

3½″ disks can be formatted in a variety of different capacities as CP/M disks. The +3 ROM cannot format 3½″ disks itself so either a utility is required on the +3 (such as The Spectrum +3 Multiformatter by Garry Lancaster), or the disk must be prepared on the PC.

DOS format disks

to access a DOS formatted 720k disk on the +3 you can use Garry Lancaster's MSDOS utility This will allow you to "log on" to a DOS format disk in drive B: and copy files from it to a +3DOS formatted 3″ disk in drive A:

Writing Images

3½″ diskettes

To read and format disks with formats other than 720kB (the +3multiformatter utility refers to this as 708K) on Windows NT you will need the FDrawcmd driver by simon owen. This will only work correctly on PCs with real floppy controllers. A good utility for writing the images is John Elliot's dsktool. It's possible to read and write 708K +3DOS format dsk images using dsktool on some USB floppy drives that have an NEC UF000x chipset. The Dell FDDM-101 module is known to work.

3″ disks

A guide to connecting a 3″ drive to a PC and reading/writing disks is available from the Spectrum Disk Preservation Project

Writing individual files

To write individual files to a +3 formatted diskette (or dsk file) you can use cpcxfs