Null Modem setup problems PC to Apple IIC+

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Null Modem setup problems PC to Apple IIC+

Hello all. I've dug up my old Apple IIC+ and much to my dismay discovered a great many of my 5 1/4 disks had been damaged in storage! So my I am without many of the tools I want to use for my Apple. I looked online read many articles and discovered a couple methods of getting disk images from my PC or Mac to the Apple II including buying an old Mac LC with Apple IIe card or setting up a null modem connection. The null modem connection seemed to be the easiest so that is what I've been trying to get to work... I am unfortuntely having a great deal of difficulty.

I have an 8 pin mini din to DB 25 cable to connect to the modem port of the apple IIC+ (this is where a lot of my confusion starts because many of documents I read for sending a copy of DOS 3.3 over the cable only seem to detail transfering to a IIe or IIGS. The GS has a similar modem jack that the IIC+ has but not the same software tools and all the IIe documents speak of SSC switches that need to be set. None of which I believe are on the Apple IIC+. I have however read that the IIC+ is SSC compatable)

I connect a female to female adapter to the end of the DB25 connector, and connect another DB25 connector that has DB9 female connection at the end that fits into Serial COM1 on the PC.

Seems simple enough.

I've followed the instructions to dump DOS 3.3 to the letter as described in ADT setups. I've tried using a DOS console to send the file using "type" and I've tried using hyper terminal to send. Neither gives any results. Using "type" command on the console on the PC seems to do nothing at all. I get a blank line return and after some time i get a new C prompt, but no activety happens on the Apple IIC+. In Hyper Terminal sending ASCII text seems to do nothing at all. I get no dialog, i get no indication that anything is attempting to transfer, and again no indication that anything is appearing on the IIC+.

I have tried using a different PC with the same result.

I have everything set right as far as I can tell (i.e. 300 baud settings etc). I type IN#2 on the IIC+ and i get a ] prompt with a slower blinking cursor but nothing seems to be transfered.

I have looked everywhere I could. On forums on news groups. And either I am not doing a proper search or I am unable to find any information specific to setting up a null modem connection over the Apple IIC+. I only find information on transfers using the IIC which has a different pin out on its modem port.

I have tried to setup a direct cable connection without the female to female db25 connector inbetween, but anytime I try to use the LPT1 port on the PC its always being used by another program and never available.

Does anyone have any information on how to setup a null modem connection on an APPLE IIC+ i would GREATLY apprciate any help you could provide me. Thank you!

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Re: Null Modem setup problems PC to Apple IIC+

I have everything set right as far as I can tell (i.e. 300 baud settings etc). I type IN#2 on the IIC+ and i get a ] prompt with a slower blinking cursor but nothing seems to be transfered.

The "null modem" everyone talks about is a physical cable (or connector) that crosses the transmit and receive lines of the serial cable. The reason you aren't seeing any activity is probably because your transmit lines are talking to each other, and the receive lines are listening to each other. Nobody hears anything.

An example from the Jameco website (no endorsement intended or implied; Radio Shack has the same sorts of things):
https://www.jameco.com/webapp/wcs/stores/servlet/ProductDisplay?langId=-1&storeId=10001&catalogId=10001&productId=181438
So, a null modem is a physical connector that swaps the tx/rx lines around. You may not have that in your setup currently.

I have tried to setup a direct cable connection without the female to female db25 connector inbetween, but anytime I try to use the LPT1 port on the PC its always being used by another program and never available.

LPT1 won't help you. It's a completely different electrical interface - you need to stick to your serial ports on the PC end.

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Re: Null Modem setup problems PC to Apple IIC+

So since the IIC+ is not getting any response when I send data over the com port I can assume that the DB25 to DB9 (This store calls it a DE9, what is the difference between DE9 and DB9?) cable that I have is not a null modem cable? How can I tell the difference between. The cable you linked looks exactly like the cable I have, however I don't know what the cable was used for as I got it out of an old dusty bin of cable wires from years past!

So if I assume the cable I have is not the correct one, if I go get the cable listed in the link you posted should I still set it up the same way:

Mini-Din8 modem out from IIC+ with DB25 male end connected to DB25 f/f gender changer, connected to DB25 male end with DE9 female end connected to serial COM 1 on the PC.

Thank you for your help! This has been a bit frustrating for me as it seemed easy to do at first.

Jon
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A 25 to 9 converter is just t

A 25 to 9 converter is just that. It takes a 25-pin port to 9 pins, and that's it. A null modem adapter usually has "NULL MODEM" printed on it somewhere. There are 25-25 and 9-9 null modem adapters. They are almost always male on one end and female on the other, so that they plug right into an existing cable with no other conversion.

http://en.wikipedia.org/wiki/Null_modem
http://en.wikipedia.org/wiki/DE9
http://en.wikipedia.org/wiki/D-subminiature

Wikipedia is a great tool.

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Re: Null Modem setup problems PC to Apple IIC+

So since the IIC+ is not getting any response when I send data over the com port I can assume that the DB25 to DB9 cable that I have is not a null modem cable?

That's a pretty safe assumption.
How can I tell the difference between. The cable you linked looks exactly like the cable I have, however I don't know what the cable was used for as I got it out of an old dusty bin of cable wires from years past!

Well, that's part of the problem. Unless you know what the function of your cable is, you'd have to test it to know what the pins do. Since it seems to be a dud in the configuration you're in now, you have to add a null modem cable in the middle.

(This store calls it a DE9, what is the difference between DE9 and DB9?)

Same thing.

There is a little info on IIc+ connections here:
http://home.swbell.net/rubywand/Csa2T1TCOM.html#016

So if I assume the cable I have is not the correct one, if I go get the cable listed in the link you posted should I still set it up the same way:

Mini-Din8 modem out from IIC+ with DB25 male end connected to DB25 f/f gender changer, connected to DB25 male end with DE9 female end connected to serial COM 1 on the PC.


Jameco and others sell null modem cables in every imaginable configuration. You want to match things up to make it easy for yourself. If I read your configuration right, you want a null modem with DB25F and DE9F ends. (If you don't get exactly that, then you might need gender changers, etc. to make it all fit.) So browse online catalogs and find one that does everything you need in one package.

I have an example of a null modem setup for an IIgs, which will give you the flavor of how the setup goes (look for the "IIgs modem port specifics" section):
http://adtpro.sourceforge.net/bootstrap.html
If I had an IIc+, I'd add instructions for that too. Wink

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RE 25 to 9

Very good information! Thank you very much. I will pick up a null modem cable and see if I can get life back into my IIC+. (I'm excited)

Edit 11/01/06:

Picked up a null modem cable and everything is working perfectly! Thank you all for the help and info!

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modem problems

One item...Just because you have a 25-25pin female-female
"adapter", don't assume it is a Null Modem Adapter. As was
mentioned, check the adapter and see if it specifies what
it is. If you need one of these you can usually get it at
a Radio Shack store. Ask for a Null Modem Adapter by name.
Or try any computer store.

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