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Getting Async DB25 serial card working in Epson Apex 100

Bill-kun

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This is a follow-up to this previous thread. I'm continuing it here because this is the real implementing of the solution now that I know what the problem is. To recapitulate:
  • My Epson Apex 100 has 1 built in parallel port and no built-in serial port. I want to use a mouse with this computer, but cannot use the parallel port.
  • I bought an original IBM Async expansion card from eBay. This card adds a DB25 serial port. The card was "pulled from a working unit" but untested.
  • I can't get the expansion card to work properly. This thread is addressing that problem.
The new info:
  • I put it in the Apex 100 and turned it on. The computer gives a series of beeps (long short short) and the screen displays nothing and stays that way.
  • I think the problem is a conflict with assigning the primary and secondary serial ports via DIP switches. See attached pictures for the Async card. There are a few sets of jumpers, but only one jumper, J13, is the kind where you slide a small black block over the two tines. That jumper is currently open.
  • The PDF manual I found online for an Epson Apex 100 unfortunately does not quite match my unit (see hyperlink). Pages A-1 through A-5 tell how to set the DIP switches.
    • The manual says the first set of DIP switches is 8 switches they control the
      • keyboard type, coprocessor type, RAM size, monitor and adaptor type, and number of diskette drives.
    • The manual says the second set of DIP switches is 4 switches and they control the
      • parallel ports and serial ports
  • On my unit, there is only one set of DIP switches, labeled "DNT10", which has 10 switches. They are currently set to 1101100101, respectively, and have been unchanged since I got the computer last year. I added the "Parallel" label myself.
    • DIP switches initial state.jpg
Any ideas on what I should change the DIP switches to, to get the Async card to work?
 

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I'm not familiar with the Apex 100, but J9 on the IBM Async card selects between primary (dot on the shunt block in the upper left position) or secondary (dot on the shunt block in the lower-right position); that is, right side up or upside down.

But you've got me scratching my head. The Apex 100 has both built-in serial and parallel ports. The manual says so.:?
 
LGR's Apex 100 matches the manual, but mine doesn't.
Epson Apex 100 manual 1.jpgEpson Apex 100 manual 2.jpg

For reference, here is the front and rear of my Apex 100. It doesn't match the manual, unfortunately. For one thing, the bottom of the front face doesn't not open to flip down. Even the parallel port is on an expansion card. According to the manuals I've found, there was also a model 100/20 and a Plus; maybe that is the difference.
Epson Apex 100 manual 1.jpgApex 100 front.jpg
 
I'm not familiar with the Apex 100, but J9 on the IBM Async card selects between primary (dot on the shunt block in the upper left position) or secondary (dot on the shunt block in the lower-right position); that is, right side up or upside down.

Can you please post the link to the IBM Async card manual? I couldn't find it myself.

Addendum: I think I found it. The photograph certainly matches my card.
http://minuszerodegrees.net/5150_516...htm#ac_adapter
http://minuszerodegrees.net/oa/OA%20...%20Adapter.pdf

Pages 20-21 shows the locations of the jumpers and how to set them. Do I just do trial and error?

And even so, I still don't know anything about the 10 DIP switches on the Apex 100 itself. Hmm.
 
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Here's the manufacturer's plate on the back. Model Epson Apex AP1001A-AB. Maybe this was the first Apex, before the Apex 100? I think "Vanilla Apex" is a good nickname.
IMG_6554_small.jpg - Click image for larger version  Name:	IMG_6554_small.jpg Views:	0 Size:	76.9 KB ID:	1231406

The manual link you gave actually goes to a long YouTube video of maritimegirl showing the Apex 100 she has.



According to the 2 document links you provided for the "vanilla Apex," yes, those specs match my computer. Also, the table of the 10 DIP switch settings is exactly what I need! :eek:ha:
Apex 100 - 10 DIP switches settings.jpg - Click image for larger version  Name:	Apex 100 - 10 DIP switches settings.jpg Views:	0 Size:	122.5 KB ID:	1231407

Before I get to implement the computer's DIP switch settings from that table, I need sleep. And, the computer is still giving the long-short-short beep pattern on boot, with nothing showing on the monitor, even without the Async card plugged in. I need a table of the beep error codes. According to Computer Hope, 3 listings agree that long-short-short means video card error.

It's too late at night for me now to continue this. I made a lot of progress, but I will have to get back to it in a couple days.

Edit: Here is the manual for the "apparently original" "vanilla" Epson Apex. Not named Apex 100, Apex 100\20, or Apex Plus. Just "Apex."
https://www.manualslib.com/manual/301959/Epson-Apex.html
 
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If this machine doesn’t have a built in serial port then frankly so far as I’m aware there is nothing on the motherboard switches you should have to touch, the async card can’t interfere with anything. Parallel and serial ports live at different standard primary and secondary I/O addresses, and they also don’t normally use clashing interrupts. So, frankly, if plugging that card into your machine made it malfunction it is probably a bad card, and it sounds an awful lot like it may have damaged your machine.
 
I got it working.

The three beeps were about the video card not working. So I concluded that was because J13 on the Async card was for putting the Async card in the slot of an IBM that is normally used for the video card. So I removed the jumper I had put on J13.

After inspecting the computer's DIP switches, I didn't have to change any of them. But I did flip switch 1 for the keyboard type, which eliminated the keyboard error I had been getting on every boot up for months.

The Async card also has two chips that rotate depending on what setting you want. I've never seen that kind of "switch" before. I set the serial port for primary serial; it had been on secondary before, but there is no secondary.

GMOUSE.COM, the Genius mouse driver, ran successfully and found the mouse. I ran PCShell 5.5 and the mouse cursor came up and I am able to move and click!

mouse 1.jpgmouse 2.jpg

https://c.tenor.com/HZOA9SNt57YAAAAC/doc-brown-bttf.gif
3dTY.gif
 
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One last question. Page 20 of the Async manual says that the lower shunt module orientation is the setting for either current loop interface or voltage interface. In this application, what is the difference, and which setting should I use?


Async page 20.jpg
 
Why in the world did you put a jumper on the Slot 8 dingus before even trying it in the machine?! Unless the card came with that already set this whole thing makes no sense at all.

And leave everything else alone. If you don’t know what current loop serial is you don’t need it.
 
Current loop is very different from RS232C signaling. Mostly used with Teletypes, which use a convention that dates back to the telegraphy days. Rather than being voltage-sensitive, it's current-sensitive, so with very long lines, the voltage can be increased to provide the required current. It was also used on some long-haul wired modem configurations.
 
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