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Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: zonaps2 on August 09, 2007, 04:07:15 AM

Title: Null modem cable doubt
Post by: zonaps2 on August 09, 2007, 04:07:15 AM

I want to use Amiga Explorer to tranfer adf's files to my A500, I'm reading that I need a nullmodem cable.
What type I need? I don't have my A500 right here so I don't know if the serial port is male or female.
My PC has a 9 pin female serial port.

What is the right cable?

1) db25M - db9M
2) db25F - db9M

Thanks!

Title: Re: Null modem cable doubt
Post by: rkauer on August 09, 2007, 04:24:42 AM

c) DB25 F on Amiga side, DB9 FEMALE on Windoz side

 BTW: You need the null-modem with complete wiring scheme, that's on Cloanto's page (http://www.amigaforever.com/kb/3-105.html).

Title: Re: Null modem cable doubt
Post by: zonaps2 on August 09, 2007, 05:09:22 AM

OK,
Anybody has made this cable?
need it to be shielded with the metallic mesh?

Title: Re: Null modem cable doubt
Post by: orange on August 09, 2007, 06:47:30 AM

if youre gonna shield it, connect the shield to ONE end only! (to prevent making loop)

Title: Re: Null modem cable doubt
Post by: Tripitaka on August 09, 2007, 10:49:17 AM

Quote

zonaps2 wrote:
OK,
Anybody has made this cable?
need it to be shielded with the metallic mesh?

YES, I have, a long time ago and no, I can't rememmber ever shielding it.
I'd take a look now but the cables packed in a large box of computer bits as I'm moving.

Title: Re: Null modem cable doubt
Post by: mrad on August 09, 2007, 11:19:51 AM

>need it to be shielded with the metallic mesh?

For 115 kilobaud and 30 feet maybe, but not for the baud rates an A500 can put out.  I can't get better than 57 kbaud even with an A1200/68030 for Amiga Explorer; at 115 kbaud the serial port splashes data bytes onto the floor. Your A500 will probably have to run at 19.2 kbaud.

If you have trouble making one, null modem adapters are still fairly common items at computer stores, though not as common as they used to be before the popularity of USB.

Title: Re: Null modem cable doubt
Post by: DrDekker on August 09, 2007, 01:02:13 PM

You should still be able to pick up a new null modem cable from 'somewhere'.

I bought mine from www.ebuyer.com for a couple of quid.  
Each end of the cable has a 9-pin and a 25-pin female connector - so compatibility/connectivity isn't an issue.  Data transfer is very reliable when used in conjunction with the 'baudbandit.device' and a 56k port setting (on a mildly accelerated A1200 that is).

Title: Re: Null modem cable doubt
Post by: zonaps2 on August 09, 2007, 05:07:42 PM

Ok,
I'm gonna build a cable about 1 meter (about 40 inches) long for an A500, so I guess shield it won't be necessary.

Title: Re: Null modem cable doubt
Post by: zonaps2 on August 09, 2007, 08:23:20 PM

Please can someone tell me if in this diagram the connector are viewed from the front or the back, 'cause it is a totally different wiring scheme.
thanks
(http://img53.imageshack.us/img53/4241/wiring925it7.gif)
http://img53.imageshack.us/img53/4241/wiring925it7.gif

Title: Re: Null modem cable doubt
Post by: rkauer on August 09, 2007, 09:07:18 PM

Hola zonaps2.

 If you look carefully at the conectors (the physical ones) you'll notice they have numbers... :roll:

Title: Re: Null modem cable doubt
Post by: zonaps2 on August 09, 2007, 09:27:32 PM

gracias!,
no los había notado :roll: