a500 serial problem

[sonni]

anyone stumbled upon a oneway-serial?

i used an a500 as a terminal for my linux, but it broke.
now with the 'new' specimen, i only get print on the
amiga screen. nothing happens, no matter how hard
i whack the amiga keyboard.

'echo randomgibberish > /dev/ttyS0' comes ok
to the other end, and serial settings are identical
at both ends.

i tried switching the nullmodemcable around, same
thing. i tried switching cia-chips, same thing. i
even switched paula for a good sport, and nothing.

and i hardly believe i have wanked something up
with my linux (not being able to 'write' to the port
n ####)

[blobrana]

Welcome!

You need a null-modem cable, (the crossover cable one)

There are two types of null-modem cable ,  (and those can be  wired for hardware handshake,  er, or not)

Have a look at the wires ...or get the right cable


----------------------------------------
Er, but the problem could be something entirely different in which case disregard everything i`ve said! :-D

[sonni]

blobrana wrote:
You need a null-modem cable, (the crossover cable one)

like i said, the cable is ok, and it worked perfectly with the
earlier amiga.

[blobrana]

Hehe,
Sry, i didn`t have my telepathic powers switched on yesterday.
You seem to know what you are doing, you  checked and eliminated the (Even) CIA chip
AND the Paula.
 And you checked the Transmit line driver chips U38 , U39...
(Assuming that you did indeed swap healthy paula and cia chips around. It is possible that
 both/all the chips are faulty)

And are you sure the software is ok...?   yea...

So,
i would still doublecheck the cable, the alternative is,
 er, beyond me...

Good luck..

[sonni]

the line driver chips i haven't tried yet. i was
kind of hoping there would be a more convenient
solution.

i still do have the earlier working amiga, so i could
try to take it's chips off. too bad they aren't socketed..

but, those would be the number one suspects for the
time being?

have to get another amiga to verify that it really is
those chips fault. wouldn't want to destroy yet another
amiga by accident

[sonni]

now i'm getting pretty frustrated.

i just bought myself another amiga, and
it is also a hong-konger.

same thing, serial works only one way.

so, it's beginning to look like a linux
or a hongkong-problem. or the serial
ports on this mobo are both toasted..

any help would be infinitely appreciated,
i have no clue what i'm doing wrong here
(since it worked mighty fine with a
german amiga).

 :-?

[jjans]

I connected my A500 to my PC which dual boots Win XP or SUSE Linux 8.1 via serial port to com1. I have only tested the serial connection under WINXP, 98, and 95. I used standard serial cables as well as a NULL MODEM box. What OS are you using on your Amiga? If it is Linux, then ignore the rest of my post.

On the WINXP machine I can connect using Hyperterm at 57600 Bps, 8N1, hardware control on,using ZMODEM protocal.

On the A500 (WorkBench 2.1), I connect using Terminus from Aminet Terminus 2.0e. On a stock A500 using the serial.device the fastest reliable connection via a normal serial cable I found to be at 28800 bps. I was able to achieve 57600 by using BaudBandit.device as a replacement BB.device aminet.

I have not yet got around to testing the connection in Linux, as I'm very new to the OS. perhaps you can tell me what Linux/Amiga software you are using so I can recreate your problem myself, and try to find a solution.

[JetRacer]

It's not like you've bent a pin in a connector nor anything..?

There's always the possibility that the dead Amiga took the x86 interface with it. But in that case you can simply switch x86 serial. You got atleast a couple. (hint: use the converter that came with the 56K modem) Or buy an usb to serial converter.

[Castellen]

The best way to test the serial TX and RX data lines, is get a terminal program, use any baud rate, and disable flow control and disable local echo.

Link the TX & RX data together (pins 2 & 3 on serial port) and type something on the keyboard, which should echo to the screen then stop echoing when you remove the TX & RX link.

If this works OK, and you still get 1 way data to the other computer, use software flow control (or no flow control for testing).  If this works, there is a problem with the hardware flow control lines, either in one of the computers, or in the null modem cable.

If the linked TX & RX test doesn't work, there is possibly a problem with the +12/-12V supply (required for RS232 transmission), the 1488/1489 line driver/receiver or the CIAs.