Discussion:
ADT Reliability
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Bobbi
2017-09-30 15:54:57 UTC
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I have been using ADTPro 2.0.2 to transfer disk images to my real Disk II, and also have been making use of VSDrive a bit too. Hardware is Apple IIe (unenhanced - although that is about to change) with SSC.

In general it is a great experience and I have been able to transfer dozens of disk images successfully. Thanks so much to David Schmidt!

However I find that the transfer (and also VSDrive) is not completely reliable. Sometimes I can transfer entire floppy images successfully. Other times, the same image will terminate with a transfer error at some random point. After this has happened, the ADTPro client is usually in a bad state and all actions (eg: 'D'irectory) will result in HOST TIMEOUT. Generally restarting the Apple II and ADTPro client gets things working again. I don't usually have to restart the ADTPro server. I am running ADTPro server under Linux if that makes any difference.

I suspect the problem is a dropped character on RS232 somewhere. Not sure if that is an overrun on the client side or something internal to the SSC or the cheap RS232-USB converter I am using. The ADTPro trace log doesn't show anything very interesting.

Does anyone have any similar experiences? Is ADTPro totally reliable or is the odd issue like this to be expected at 115Kbaud?

I don't really care too much when transferring floppies, since usually two or three retries will do the trick. However it makes using VSDrive rather miserable.
skipperdoodle1947
2017-09-30 16:47:17 UTC
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Post by Bobbi
I have been using ADTPro 2.0.2 to transfer disk images to my real Disk II, and also have been making use of VSDrive a bit too. Hardware is Apple IIe (unenhanced - although that is about to change) with SSC.
In general it is a great experience and I have been able to transfer dozens of disk images successfully. Thanks so much to David Schmidt!
However I find that the transfer (and also VSDrive) is not completely reliable. Sometimes I can transfer entire floppy images successfully. Other times, the same image will terminate with a transfer error at some random point. After this has happened, the ADTPro client is usually in a bad state and all actions (eg: 'D'irectory) will result in HOST TIMEOUT. Generally restarting the Apple II and ADTPro client gets things working again. I don't usually have to restart the ADTPro server. I am running ADTPro server under Linux if that makes any difference.
I suspect the problem is a dropped character on RS232 somewhere. Not sure if that is an overrun on the client side or something internal to the SSC or the cheap RS232-USB converter I am using. The ADTPro trace log doesn't show anything very interesting.
Does anyone have any similar experiences? Is ADTPro totally reliable or is the odd issue like this to be expected at 115Kbaud?
I don't really care too much when transferring floppies, since usually two or three retries will do the trick. However it makes using VSDrive rather miserable.
Weird. I have never had such a problem, running from Windows 7. I routinely back up my BBS from the Apple IIe to my Windows machine, which is a 32 meg disk image. I usually do this once a day for over a year now, and have never had an issue. I guess this doesn't help much, sorry. :)

PS: I do all my development work on the Windows disk image (via AppleWin, then transfer changes back to the Apple via ADTPro), so I am assuming I would have seen some symptom if there was a problem with the transfer.
Bobbi
2017-09-30 16:52:54 UTC
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One possibility that had occurred to me is that a character gets dropped due to the fact that interrupts are disabled for longer than necessary on *unenhanced* IIe. Although maybe that only applies with 80 column mode active, not sure.

I have an enhancement kit on the way in the mail, so will be interesting to see if that makes any difference to ADTPro reliability. (The main motivation for enhancing my IIe is that the scrolling sucks in 80 column mode with unenhanced ROMs).
David Schmenk
2017-09-30 19:26:44 UTC
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Post by Bobbi
One possibility that had occurred to me is that a character gets dropped due to the fact that interrupts are disabled for longer than necessary on *unenhanced* IIe. Although maybe that only applies with 80 column mode active, not sure.
I have an enhancement kit on the way in the mail, so will be interesting to see if that makes any difference to ADTPro reliability. (The main motivation for enhancing my IIe is that the scrolling sucks in 80 column mode with unenhanced ROMs).
Most likely the issue is on the host side. What machine are you running the ADTPro server on? You mentioned Linux. I've had problems with VSDrive doing large transfers on a low end Linux computer.
Bobbi
2017-09-30 19:58:23 UTC
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Maybe I will see if I have a Windows laptop in the closet somewhere. I try not to run Microsoft software newer than Applesoft ;)
Bobbi
2017-09-30 22:33:15 UTC
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Found an old laptop in the closet. ADPPro / VSDrive seems to work much better running on a Windows 7 host. I am going to guess that the Linux driver for the cheapo USB-Serial device I have drops characters, or maybe ADTPro doesn't like OpenJDK. Either way, it is nice to have it working properly now. I guess this Windows 7 machine is now an Apple II peripheral!
Steven Hirsch
2017-10-01 13:32:19 UTC
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Post by Bobbi
Found an old laptop in the closet. ADPPro / VSDrive seems to work much
better running on a Windows 7 host. I am going to guess that the Linux
driver for the cheapo USB-Serial device I have drops characters, or maybe
ADTPro doesn't like OpenJDK. Either way, it is nice to have it working
properly now. I guess this Windows 7 machine is now an Apple II
peripheral!
There are some truly terrible USB<-->Serial adapters out there. I've had my
best luck with FTDI based units under Linux.
Bobbi
2017-10-01 16:52:44 UTC
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The first USB-Serial adapter I tried dropped characters so bad I could not bootstrap ADTPro at all.

This is the second one I have tried. It seems fine under Windows but drops characters occasionally under Linux. It uses the chipset 'CH341' for what it is worth.
David Schmidt
2017-10-01 18:56:45 UTC
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Post by Bobbi
It uses the chipset 'CH341' for what it is worth.
It's not worth much. You'll be happier with FTDI.
Bobbi
2017-10-01 19:37:27 UTC
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Can't complain too much - paid $6 for it and it was good enough to bootstrap my 'new' IIe (even included the 9-25 pin adaptor). Seems to work okay with the Windows drivers too, so it would satisfy the majority of users. Still I think I will find a better RS232-USB adaptor - probably FTDI as you suggest.
James Davis
2017-10-01 01:36:18 UTC
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On Saturday, September 30, 2017 at 8:54:58 AM UTC-7, Bobbi wrote:
. . . the cheap RS232-USB converter I am using.

It has been said before the cheap ones don't work well. You should get one directly from adtpro.com or get the one they recommend.
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