Amiga Explorer Connection Issues

[arongooch]

Recently I acquired an Amiga 2000 and have made up my own RS232 Null modem cable. On Windows side and using the Amiga Explorer Setup function I managed to successfully copy across Amiga Explorer to the 2000 with no problems. I can read the readme.txt on the Amiga and Amiga Explorer launches on WB no issues there at all.

The problem is now when I run Amiga Explorer on the Amiga side and then try launching it on the Windows side I most times get a serial connection error. On very rare occasions I do manage to read the Amiga and it shows it's contents etc but as soon as I click on anything the serial connection error occurs again. I have the same baud settings on both machines and packet size, retries etc. Im only using 19200 baud but have also tried as low as 9600. Im also using hardware handshaking.

I cannot understand how I can reliably copy across Amiga Explorer perfectly and multiple times but then AExplorer refuses to establish a connection on the PC side. I am using a cheap Chinese Prolific USB to RS232 adapter and am wondering if this could be the issue?

 I'd like to also point out I am fairly cluey at making these cables and using Amiga Explorer but this issue I am having has completely stumped me. Any ideas would be great appreciated

[AmigaEd]

I would recommend that you read this if you haven't already.
https://www.amigaforever.com/kb/14-109

Also, USB to SER adapters can be problematic, especially when interfacing to older hardware on the SER side.
On older hardware the serial port hardware is often looking for more significant voltages than the USB to SER adapter can produce. If I remember correctly, the Amiga 2000 was designed for +10 / -10 VDC on the serial port. See this https://en.wikipedia.org/wiki/RS-232
Sometimes you can get lucky and the USB to SER will work cause the levels are right on the edge of what is considered a valid level. Other times it won't work no matter what. And still other scenarios like works sometimes and then stops. An additional load on the computer power supply can cause the voltage to dip just low enough that the RS232 signals drop below the "valid" levels. For example, the RS232 works when the floppy drive is not running but doesn't work when it is running.

[arongooch]

That webpage was the source of information I used to make the cable.

I have built a few of these cables in the past and all have worked well. I did manage to get an older cable I made and can confirm it is not the cable. Does indeed look like it's an issue with the Prolific USB to RS232. These things are absolute rubbish it from what I can see.

Im going to use the native motherboard serial port on my Windows PC with a backplate connector and use that instead. Hoping this fixes the issue.

Also I tried out a newly acquired MultiFace3 card with the same results. If I had my scope here where Im temporarily living I would check out what the signal levels are but Im thinking what you say about the levels being too low on the Prolific converter could very much be the issue.

[AmigaEd]

Definitely go for the "real" serial port on the PC side if that is an option.

The O-scope for sure would be the "tell-all". BTW... many really nice and inexpensive pocket O-Scope options out there. I've carried a BitScope 10 with me for several years now and it has more than paid for itself. There are also other less expensive options out there.

I was looking at the data on the MultiFace3 board and had to laugh a bit when I read this in the specs... "the MC68681 is a 4 MHz version overclocked to 7 MHz in order to reach the 115200 bps transfer rate"

Oh how times have changed... LOL.

[QuikSanz]

@arongooch,

At work we sell A USB to DB9 Adapter for connecting to a RS232 port on our Entry Phone Systems. We only guarantee this one "Chippy-X" and comes with a link for Windows driver.
Even works with stubborn Win10 that dropped all support for modems.

DoorKing P/N 1815-037

[giZmo350]

BTW... many really nice and inexpensive pocket O-Scope options out there. I've carried a BitScope 10 with me for several years now and it has more than paid for itself. There are also other less expensive options out there.

I'm a huge DOS dork, 486/Pentium freak, DMA bus boy! Serial Comms nut! Even 10 years ago you couldn't buy a new, cheap o'scope. I - MUST - HAVE - ONE - OF - THESE! :laugh1:

[AmigaEd]

I'm a huge DOS dork, 486/Pentium freak, DMA bus boy! Serial Comms nut! Even 10 years ago you couldn't buy a new, cheap o'scope. I - MUST - HAVE - ONE - OF - THESE! :laugh1:

gizmo350, I was mentioning the Bitscope Picoscope 10 purely for its ease of portable use.

If you are looking for something to use on the workbecnh there are also many good options such as the Hantek DSO5202P 200MHz, 2 Channel Digital Storage Oscilloscope (which I have and am very happy with) or there is also the Rigol 1000 Series scopes which I've heard a lot of good things about.

[giZmo350]

Thanks AmigaEd!!!! Been wanting something like this for a long time! I didn't know they came down in price this much! Ordering a Hantek tomorrow!

Just for the heck of it I compared price to ebay - people on ebay are simply crazy!

https://www.ebay.com/sch/i.html?_from=R40&_sacat=0&_nkw=Hantek+DSO5202P&LH_PrefLoc=2&_sop=16

Again, thanks!

[AmigaEd]

Thanks AmigaEd!!!! Been wanting something like this for a long time! I didn't know they came down in price this much! Ordering a Hantek tomorrow!

Just for the heck of it I compared price to ebay - people on ebay are simply crazy!

https://www.ebay.com/sch/i.html?_from=R40&_sacat=0&_nkw=Hantek+DSO5202P&LH_PrefLoc=2&_sop=16

Again, thanks!

Ha! Yeah Crazy is an understatement. Just want to mention that I'm not associated with Circuit Specialists in anyway but they have treated me right on everything I've bought from them. Make sure you get on their mailing list as they often send out 10 to 15% coupons for any items they sell. This can help when it comes to buying accessories ,etc.

[giZmo350]

Thanks again El Duderino! Just signed up for their Newsletter/Mailing List!

[arongooch]

Thanks for hints everyone. Really appreciated.

I can confirm it was indeed the USB to RS232 converter. From my experience these things are useless. Perhaps not all of them but certainly the Prolific ones ive used in the past.

I ended up using my motherboards native serial port with a 9 pin rear panel breakout connector and have had flawless results at 115200 baud continuously with AExplorer running in Windows 10 and with the cable I had made following instructions from AmigaForever page. Very happy now

[AmigaEd]

That is excellent news!
Yes, they can be troublesome. I've had trouble in the past, with the USB to Serial adapters both for hobby projects and in commercial applications.