Portable 1.44MB drive using external floppy connector

[rosaage]

Hello, Currently I have to connect a 1.44mb 3.5" drive with the case of the computer open and another computer next to it to power the drive. So I was thinking about making a special cable with the external floppy drive connector plug in one end and two floppy cables + two small 4-pin power connectors, or if it doesn't support power make a power supply from parts I have. Does anyone have the pinouts I need for this project?

 

[sergey]

Not sure I completely understand your question... Why you can't power the drive from the computer you're connecting it to? If it doesn't have enough floppy drive connectors you can add one, for example using a Y-splitter.
If you'll decide to make a power cable yourself, keep in mind that 3.5" floppy drives usually only need 5V, so two wires (ground and +5V) are enough.

 

[rosaage]

Sorry my fault for not explaining better, There is no room for additional floppy drives, So I wanted to make one I can connect to the port on the outside like a external floppy drive. Kinda like this: http://disk2fdi.joguin.com/D2FCABLE.htm but for the external floppy connector not parallel port

 

[modem7]

Not sure I completely understand your question...

Looking at rosaage's posts, he/she has an IBM 5155. If that is the computer being discussed, then I think the desire is to (from time to time) attach his/her 1.44M drive to the external connector on the IBM 5.25" floppy controller card. Let's see if rosaage confirms that.

 

[bobba84]

On eBay I have seen simple power supplies with a molex connector on them. I think they come with cheap eSata or usb to ide cables. Maybe one of them with a molex to small floppy power adapters could suffice for thr power portion of your project?

 

[Malc]

Not sure if this is any good but i use a cheap Chinese 5v 12v power supply to power hard drives and floppy drives, All you will need is an adapter cable for the 3.5" floppy drive like this.

 

[rosaage]

modem7 is right, I want to connect an internal 1.44mb drive to the external connector on a ibm isa floppy controller card. Does anyone have a pinout or something for this port?

 

[sergey]

modem7 is right, I want to connect an internal 1.44mb drive to the external connector on a ibm isa floppy controller card. Does anyone have a pinout or something for this port?

The schematic of the IBM XT floppy disk adapter is given on pages D-45 to D-48 of IBM XT Technical Reference. Connectors specifically are on page D-45. P2 is the internal floppy connector, J1 is the external floppy connector. You can deduct mapping between signals and pin numbers using that schematic. But please let us know if you need any help...

 

[Stone]

modem7 is right, I want to connect an internal 1.44mb drive to the external connector on a ibm isa floppy controller card. Does anyone have a pinout or something for this port?

That controller won't support a 1.44 MB drive.

 

[sergey]

That controller won't support a 1.44 MB drive.

It should work with 1.44 MB drive using 720 KB diskettes (or 1.44 MB diskettes with covered density detect holes).

 

[rosaage]

If i read it right I only need to mach the pins from P2 to J1 like Pin 7 on J1 (Motor enable 3) gets connected to pin 12 (motor 1) on the 34 pin floppy connector, but some of the numbers are a bit unclear to read: http://gyazo.com/bd03c81c6eb98f082a32322670878e52 like between 11 and 13 on J1.
After counting and reading I found this connector: http://www.ebay.com/itm/110918186601 with this around it http://www.ebay.com/itm/181226970176
Does this seem right or am I missing something? I'm planning on cutting the MB connector of a 34 pin floppy cable and connecting it to the db-37 connector.

 

[Stone]

It would be soooooooooooooo much easier to run a standard FDD ribbon cable from the internal connector to your drive outside the computer.

 

[Caluser2000]

You can get those nice fancy fdd cables to tidy things up a bit if need as well.

 

[rosaage]

I don't want to open the case everytime I want to connect a 1.44mb drive. the internal connector already has 2 drives connected

You can get those nice fancy fdd cables to tidy things up a bit if need as well.

What do you mean?

 

[Caluser2000]

What do you mean?

http://www.amazon.co.uk/gp/product/...oduct_details/279-1480250-2009667?ie=UTF8&me=

 

[Stone]

I don't want to open the case everytime I want to connect a 1.44mb drive. the internal connector already has 2 drives connected

You can make a ribbon cable splitter. I did it on my 286 in 1990 and it wasn't that difficult. I had a 1.2 and 1.44 drive inside and a 360K outside. I ran power and the ribbon with a splitter on it outside the case for easy access. I used one of these as the external splitter:



This little double sided card edge connector allowed me to manually switch from one floppy drive outside the case to another which was inside the case.

 

[MikeS]

You can make a ribbon cable splitter. I did it on my 286 in 1990 and it wasn't that difficult. ... This little double sided card edge connector allowed me to manually switch from one floppy drive outside the case to another which was inside the case.

Yes, but using the external connector should let you use the external drive(s) simultaneously (up to four total, without having to switch), no?

AFAIK the external cable is a straightforward IDC ribbon cable with the pin34/37 ends aligned. See modem7's excellent post below.

 

[modem7]

I have just constructed the cable that the OP is seeking.
I added a 37-pin IDC type connector to the end of a standard (twisted) floppy cable.
Added to CONFIG.SYS of my DOS 3.3 based IBM 5160 was: DRIVER=\DOS\DRIVER.SYS /d:2/t:80/s:9
Read and executed the contents of a 720 diskette.

 

[modem7]

AFAIK the external cable is a straightforward IDC ribbon cable with the pin1 ends aligned.

I thought that at first too, but discovered otherwise.

 

[Stone]

Yes, but using the external connector should let you use the external drive(s) simultaneously (up to four total, without having to switch), no?

I've never used the external connector on the XT's floppy controller (if that's what you're referring to) and I don't know how it works.