OS X 10.6 + Airport Express + Keyspan USB to serial adapter = Imagewriter?

Thanks for the report, adsfushi72.

The Keyspan adapter seems to be the only one people have reported the slightest bit of success with, so I'd be reluctant to try anything else. USB-parallel adapters have trouble as well. I believe there are only two brands known to work.

I may risk the $30 to find out. A direct connection to the computer would be acceptable, though reluctantly. I generally use the Imagewriter from only one computer.

Well, I got a Keyspan USA-19HS adapter, but it appears I'll need another cable adapter before I can even get started. Some questions while I wait:

• The Keyspan's DB-9 connector has male signal pins, but female hardware, which seems strange. I ordered a DB-9 m/f extension that appears to have compatible hardware, and I have an original mini-din 8 to DB-9 female that I used with my old SE/30. Does anyone know if the Imagewriter will need a swap a/k/a "null modem" cable with the Keyspan?
• Rather than unplug the Appletalk option board, I simply opened DIP switch SW2-4. It's not necessary to remove the Localtalk option board to enable the Imagewriter's serial port, is it?
• Has anyone made this work? Google doesn't show many hits.

One step forward...

It was necessary to run the Linux Printing Foomatic driver installer *while the Keyspan is connected*; this is critical for the driver to recognize the printer. The Imagewriter II and Keyspan drivers then appeared in Printer Setup Utility. Good so far!



Problem is, performing a print job goes nowhere:



It says "printing" but it's not.

To connect the Keyspan to the Imagewriter I am using a null modem (swap) cable and the DB-9 to mini din 8 adapter that I used with my original Mac Plus (I think). I also tried a straight DB-9 cable with the correct hardware, but the print dialog says the printer is busy, "will try again in 30 seconds", so I have reason to expect the Keyspan is talking to the Imagewriter when using the swap cable - I don't know if the DB-9 to mini din 8 cable swaps pins 2 and 3 or not, hence the reason for trying the null modem cable as well as a "straight" one.

I have not yet removed the Appletalk card from the Imagewriter; I just opened SW2-4, so perhaps the card really has to be removed...? I'll do that as soon as I remember how it went in to begin with.

The Keyspan presents DB-9 male connector pins, but it has female hardware (nuts) which I thought confusing.

For the Imagewriter, the only mini-din 8 adapter I have terminates with a DB-9 female connector which also has nuts. I thought I used this with my original Mac Plus and Imagewriter, but I could be wrong - it has an Apple logo on it, but it might have been for a modem. Since this adapter also has female hardware (nuts), I can't just connect the two directly, but I took this as a hint that I shouldn't just file off the offending hardware :-/

I got around that problem by purchasing a DB-9 m/f cable, so now all the attaching hardware matches - both ends of this cable are equipped with screws. Since I don't know if the DB-9 to mini-din 8 adapter was intended for a modem or a printer, I also purchased a DB-9 m/f "null modem" cable, what I call a crossover, so I could try both.

You should have your speed set to 8-one-noparity 9600 unless you changed the switches.

I haven't changed the DIP switches - they're still set 9600, 8-1-N. I would have thought the Keyspan would have some provision for setting its serial port baud rate, but there doesn't appear to be any way to do that... I'm basically going off of the Linux Foundation's general recommendation to use the Keyspan adapter, but without additional documentation it's difficult for me to determine exactly how everything is supposed to work.

I tried removing the card, it makes no difference 😟

What book are you referring to? Fortunately I have the Imagewriter II manual, with a pretty good pinout diagram. I was hoping not to have to get that involved, especially since I don't know what pins the Keyspan its using for its signals. It has no separate power supply and I believe a USB port only supplies +5v so it's probably not truly RS-422/3.

I was hoping someone would say "buy this cable from Amazon" but I guess I'll have to get my hands dirty (sigh).

Thank you Grant, that pinout matches what I have in the Imagewriter II manual. It is indeed a mirror image of the printer's socket, or I can think of it as a picture of the cable end.

Apparently Apple doesn't use pins 2 and 3 for Tx and Rx...! But then again it's RS-422/423. As far as I know there is no standard DB-9 pinout for that, so all bets are off.

Obviously this presents a fundamental problem. I would imagine the Keyspan is using standard RS-232 pinout designations, and if that's the case those signals aren't going anywhere with what I've patched together, null modem or not. At least it explains things.

Sure wish I could find that magic cable... Oh well, it's just tedium to sort them all out.

That's great information Grant, thank you.

My first challenge is to identify the Keyspan's DB-9 pinouts, which I imagine ought to be either RS-232 DTE or DSE but conventional nonetheless. I emailed Keyspan/Tripp-Lite tech support with that question but I'm not holding my breath waiting for an answer.

Caution: It is very tempting to look at the diagram of the DIN8 pins and say "Oh this is the socket rather than the plug." ... the pin numbers are WRONG.

That's exactly what I did! You can imagine the aggravation you just saved me with this clarification.

Rather than build a converter cable as you suggest, I think the simplest solution is to design a DB-9 to mini-din 8 cable using the correct signals. Mini-din 8-pin connectors are actually easily found on eBay, but I have lots of Localtalk cables and PhoneNet adapters I can sacrifice. I also have some DB-9 hardware so it will all look nice (eventually).

This ought to be enough information to cobble a cable together. I'll use your connection diagram - I was about to work on that last night but you've already done the work for me 🙂

Just to be sure Grant... here is the picture from my Imagewriter II user's manual, Appendix D, page 126:



Are the pins in this figure numbered correctly, or not?

Here is the entire page (too big to fit nicely on the discussions board). To your knowledge, are tables D-4 and D-5 accurate?

Thanks for the link Jan!

Apparently Tripp-Lite's site uses cookies for navigation (arrgh!!!), so it wasn't as easy as following the link, which just took me to the product's main page. Another case of page designers showing off their cleverness.

I had looked for a pinout before but couldn't find one, but knowing you found it I eventually did too:



So... if the Imagewriter II manual's Figure D-1 and Table D-4 above are each correct, I believe this is how I should construct my cable:


mini-8 ... Keyspan DB-9
1 DTR ... 1 DCD, 6 DSR, 8 CTS (jumpered together at DB-9)
2 DSR ... 4 DTR
3 Tx- ... 2 RX (or just leave it open)
4 SG ... 5 GND
5 Rx- ... 3 TX
6 Tx+ ... (open)
7 (open) ... (open)
8 Rx+, 4 SG (jumpered together at mini-8) ... (open)
(not implemented) ... 7 RTS (open)
(not implemented) ... 9 RI (open)

What do you think?

A normal serial port on a PC is arranged like that.

That explains it. Nothing's "normal" about a PC, as far as I'm concerned.
🙂

Thank you Grant... as I understand it, I should consider the pin diagram incorrect and "reverse" pins 1 & 2, 3 & 5, 6 & 8 from what's shown in the above Figure D-1. Correct?

According to Inside Macintosh (which I don't have), are the pin designations in Table D-4 correct, notwithstanding the incorrect Figure D-1 (in other words, does the table reference the "correct" pins)?

You do want to ground DIN8 pin 8, not leave it open -- from which side of the cable does not matter.

Thanks for the clarification, I believe the intent is to prevent the Imagewriter from receiving random data, correct?