RS-232 and half-duplex PPP connections

[pkillo]

[My apologies if this is not in the right forum; I couldn't quite figure out where to put these questions.]

I'm trying to connect my 3000 to the server next to it and set up a PPP connection between them. I don't want to surf the web from the Amiga; I just want to ftp files from one of the machines I do surf from so that I can stop taping over the high density holes in floppy disks to get files onto the Amiga.

I have a few questions about the Amiga side of this; I haven't setup a ppp server in years but I'm sure I can manage it. However, I'd like to run a half-duplex connection between the systems so I'm not wasting half of the capacity of the connection. [I have RS485 ports on the server, but no parallel port, so I suspect that RS-232 is going to be the best I can do for speed.] I'm fairly certain, someone correct me if I'm wrong, that I am going to need to build my null modem adapter and cables to support the lines for RTS/CTS hardware handshaking in order to run at half-duplex.

So, I'm wondering about the Amiga side: are there any oddities with the serial port, akin to those found in a Mac's DIN connector modem port, or am I looking at a standard connection? Will the Amiga support a transmission rate of 115,200 bps [or better yet 230.4kbps?] or am I going to have to run it at a lower speed?

I'm also wondering what would be the best TCP/IP stack and PPP driver to use on the Amiga, as there seem to be a couple of choices. Is AmiTCP better than Miami, or vice versa?

[hit]

i've once used this outline for creating a cable, connecting an A500 to a winxp machine (amiga 25pin to pc 9pin):
http://www.amigaforever.com/kb/3-105.html

Speed depends on the cpu you have. 115200 should work. more i'm not sure.

if you manage to get a network card, you can try this:
http://jpv.wmhost.com/NetworkBootDisk/

i hope this helps a bit.

[illy5603]

I don't know if this helps but the built in serial port on the Amiga 3000 did not have the 16c550 UART of units like the GVP I/O extender. I don't know what this means exactly for you but I remember getting crappy results at speeds over 19200 from my 3000 running RTS/CTS with a modem.

[Ed Cruse]

Originally Posted by pkillo

[My apologies if this is not in the right forum; I couldn't quite figure out where to put these questions.]

I'm trying to connect my 3000 to the server next to it and set up a PPP connection between them. I don't want to surf the web from the Amiga; I just want to ftp files from one of the machines I do surf from so that I can stop taping over the high density holes in floppy disks to get files onto the Amiga.

I have a few questions about the Amiga side of this; I haven't setup a ppp server in years but I'm sure I can manage it. However, I'd like to run a half-duplex connection between the systems so I'm not wasting half of the capacity of the connection. [I have RS485 ports on the server, but no parallel port, so I suspect that RS-232 is going to be the best I can do for speed.] I'm fairly certain, someone correct me if I'm wrong, that I am going to need to build my null modem adapter and cables to support the lines for RTS/CTS hardware handshaking in order to run at half-duplex.

So, I'm wondering about the Amiga side: are there any oddities with the serial port, akin to those found in a Mac's DIN connector modem port, or am I looking at a standard connection? Will the Amiga support a transmission rate of 115,200 bps [or better yet 230.4kbps?] or am I going to have to run it at a lower speed?

I'm also wondering what would be the best TCP/IP stack and PPP driver to use on the Amiga, as there seem to be a couple of choices. Is AmiTCP better than Miami, or vice versa?

The Amiga serial port is fairly standard. I believe the hardware will do 115,200, but the speed at which you can receive depends on the speed of your Amiga. If you simply do a standard null modem cable you can do hardware or software flow control, full or half duplex. This info is for RS232, I don't know how this relates to RS485. Seems like RS485 is a balanced system designed for two twisted pairs, one receive and one transmit. RS232 is not balanced.

db25 to db25 null:

2 - 3
3 - 2
4 - 5
5 - 4
6 - 20
20 - 6
7 - 7

db25 to db9 null:

2 - 2
3 - 3
4 - 8
5 - 7
6 - 4
20 - 6
7 - 5

[keropi]

-or -
just get a DENEB from amigakit.com and transfer files with usb2.0 easyness...

[pkillo]

@illy5603: Bah. I thought it might be an 8250 UART. That's no good, I know from the old days that those chips won't usually work reliably past 38,400 bps.

@Ed: It does follow the standard pinouts, then. Thanks. I wanted to make sure there were no surprises awaiting me; I'm a convert from the 68k apples and they had _wierd_ serial ports. When I ran a BBS from my IIsi, I had to use a custom built cable connected to the printer port to get it to work at all. (Not to mention having to hack the OS so holding down the mouse button didn't drop the line I was using for CD!)

I only mentioned the RS-485 out of angst that I don't have parallel port on the server; I know it's not electrically compatible with anything on an Amiga.

Keropi: The Deneb card would be sweet to have, for sure, but $180 is a lot to spend for a file transfer solution. The Deneb does much more, but I doubt I'd take advantage of it enough to justify the cost. I'm more likely to buy an XSurf or a Buddha/Silversurfer combo for that kind of money!

I think I will look into buying a cheap PCI-based parallel port for my server instead of using the serial at all; even if the Amiga side turns out to force me to use the slowest mode the standard defines I should still see 300kbps, that makes it about 25 seconds to transfer a disk image. I can live with that for the $25 it will cost for a dual-port PCI IEEE-1284 card.

[Ed Cruse]

Originally Posted by pkillo

@illy5603: Bah. I thought it might be an 8250 UART. That's no good, I know from the old days that those chips won't usually work reliably past 38,400 bps.

@Ed: It does follow the standard pinouts, then. Thanks. I wanted to make sure there were no surprises awaiting me; I'm a convert from the 68k apples and they had _wierd_ serial ports. When I ran a BBS from my IIsi, I had to use a custom built cable connected to the printer port to get it to work at all. (Not to mention having to hack the OS so holding down the mouse button didn't drop the line I was using for CD!)

I only mentioned the RS-485 out of angst that I don't have parallel port on the server; I know it's not electrically compatible with anything on an Amiga.

Keropi: The Deneb card would be sweet to have, for sure, but $180 is a lot to spend for a file transfer solution. The Deneb does much more, but I doubt I'd take advantage of it enough to justify the cost. I'm more likely to buy an XSurf or a Buddha/Silversurfer combo for that kind of money!

I think I will look into buying a cheap PCI-based parallel port for my server instead of using the serial at all; even if the Amiga side turns out to force me to use the slowest mode the standard defines I should still see 300kbps, that makes it about 25 seconds to transfer a disk image. I can live with that for the $25 it will cost for a dual-port PCI IEEE-1284 card.

I've made a lot of serial cables to connect Amigas to PC so the Amiga is pretty standard, except that the Amiga serials have power on them. The power comes in handy sometimes, but can be a problem when using special purpose cables. If you stick with a standard 7 wire or 3 wire cable you shouldn't have problems.

[pkillo]

Power? OK, that's weird. I guess it would be useful, I've just never heard of any other system having that.... (probably my ignorance, though, I'm sure that someone will now post a list of half a dozen systems built that way! )