Amiga Explorer max. serial Speed on A2000 with 68030
 

Just connected my A2000/68030 (Workbench 2.0) through a nullmodemcable with a PC and established successfully a connection with the Amiga Explorer. For starting i used the defaultsetting of 19200bps and was able to transfer a few *.adf to the PC. Now would like to increase the serial speed a bit. Googled around and saw, that with an 68030 it should be possible to run a 115200bps connection. If I go to PREFS - SERIAL, max speed I can set there is only 31250. Are higher speeds only possible with Workbench 3?

There are several replacement serial devices in Aminet - but can't say which one is preferable. 115200 is possible - but probably with a RTG equipped system that leaves resources free (my A500T with RTG runs it fine).

I think the standard serial port is limited to those speeds. Isn't it?

I've used both baudbandit and 8n1 - I seem to remember that 8n1 gave me a slight boost but that baudbandit was the most stable.

I tryed this one: http://aminet.net/package/util/sys/SerialPrefs292
After installation (Installer didnt work on WB2.x, so I had to install it manually) in Prefs I had another (same) "Serial"-Icon with which it was possible to change settings to 115200 (once you set that one to 115200, and go to the standard "Serial"-Icon, it shows the minimum setting). So not sure if "SerialPrefs292" just "overrides" the standard settings and which one is valid finally?

Also once you have that tool installed, you still need to configure AExplorer with Parameters to run with higher speed than 19200. When you start AExplorer without parameters, it displays quick information that speed is (by default) 19200bps.

The params on Amigaside are something like "AExplorer Connection Serial Serbaud 115200". To be able to use it, you need to configure it first with the param SERDEVICE, but above package doesnt contain a *.device file...

@zipper & jbenam:
Did you ever configured yourself AExplorer on Amiga side with params to run higher than 19200?

Just had a look at the baudbandit package (http://aminet.net/package/comm/misc/baudbandit1.4b) which includes such a file (BaudBandit.device). Will give it a try.

I just remembered - the serial speed you configure in Prefs isn't used by AExplorer! Amiga Explorer comes with its own tooltype which decides the serial speed. It's entirely independent of the Serial prefs and can do whatever speeds you want it to (and you Amiga/serial.device can support!), just remember to set it to the same speed on the PC (same thing, you need to configure the speed in AExplorer, not in windows).

Anyway, yes, I seem to remember that I run AExplorer via serial on my A4000 at home at 115200 baud. Got to be said that I use the motherboard's internal serial (no China-made USB adapters! :D) and that my A4000 has got a 040 in it along with loads of fast RAM.

I suppose you can try, your A2000 should be able to do that with a bit of fast RAM as well...

Just copy over the baudbandit.device to DEVS: and edit the AExplorer tooltype to use it, otherwise it'll default back to the OS's standard serial.device .

Ah, thanks for the hint with the Tooltype! Ok, it goes like this: With serial.device and 19200bps it takes ~10Min for 1 Disk. With 38400 around 5Min per Disk. I can also set it to 57600 and takes about 3Min per Disk. 115200 didn't work with serial.device. So I tryed with baudbandit and 8n1 (both *.device copied to the DEVS directory and then changed the tooltype appropriately). Both also work with max 57600, but not anymore with 115200. So I guess max. serial speed on A2000 with 68030 is 57600bps...

Have you tried to drop the screenmode to 2 colours? It might help. Or use http://aminet.net/util/misc/add36k.lzh

Amiga Explorer connected over a serial port has a very poor optimization.

The best transfer rates (115200) can be reached with Twin Express, but the drawback is the limitation to the old MSDOS filesystem name and space restrictions.

http://aminet.net/search?query=twin+express

@PeterK: Thanks, might give it a try someday too

@zipper: I'll try out if there is any difference with 2 colors
(and will also try with serial, 8n1 and baudbandit device)

No difference with 2 Colors.
When trying with 115200bps:

1.)
Serial.device:
When starting "Amiga Explorer": Error reading from COM port

2.)
8n1.device:
Can start Amiga Computer
After short time when trying to copy an ADF:
"Error copying file" - "Error reading from COM port"

3.)
BaudBandit.device
When starting "Amiga Computer": Error reading from COM port

4.)
New 8n1.device (68030 Version):
Can start Amiga Computer
Error copying file

5.)
New 8n1.device (68000 Version):
Can start Amiga Computer
Error copying file

6.)
artser.device
When starting "Amiga Computer": "The handshaking failed"

If I remember correctly if you are using the stock serial port on the A 2000 you will not get reliable transfers much past 33 kbaud. To get 115200 you would need a serial card/multiport card installed.

I tried using it with DOSBox - definitely not worth the hassle.

True, the Amiga ports aren't buffered so you can't reach really high speeds with them. Will check again my A4000 during Xmas and I'll see if I'm really using 115200 or not :)

More than 20 years ago, when I was still using my A2000 + A2620 (68020@14Mhz) connected to a 386 PC, TwinExpress was definitly the fastest and the only serial transfer tool that was able to work reliable with 115200 bps over a standard serial port. If I remember it correctly, it has an optional data compression to achieve the best transfer rates. Of course, you have to read the docs, but there is no hassle to learn how it works.

Btw, it seems that you are using a serial cable with the wrong connections. You need a dummy hardware handshake nullmodem cable (RTS and CTS connected) in order to use 8N1 or baudbandit.device. Sorry, but I don't remember the pin to pin connection layout anymore. And my current PC has no serial port at all.

Some tips for getting the best possible serial throughput:

• Make sure your system's VBR points to 32-bit fast RAM
• Make sure the system stack pointer (SSP) points to 32-bit fast RAM
• Make sure Kickstart is in 32-bit fast RAM
• Make sure the CPU data cache is enabled (it should already be)

You could also try to find a cheap used Zorro II serial card. At least a few years ago they were relatively easy to find, due partly perhaps to people no longer needed them once they had broadband internet access.

By the way, what make of CPU card do you have? At least GVP ones had a patch to improve serial operation in conjunction with the on-board SCSI controller.

Mark, thanks for your reply - but I'm sure as a normal user I can't follow you...

> Make sure your system's VBR points to 32-bit fast RAM

With something like this?
http://aminet.net/package/util/boot/vbrmov23

> Make sure the system stack pointer (SSP) points to 32-bit fast RAM

Can you be more specific how to do that?
Not sure where to begin here:
http://www.lmgtfy.com/?q?amiga+move+...+stack+pointer

> Make sure Kickstart is in 32-bit fast RAM

Would this here be the right place to start looking how to do that?
http://eab.abime.net/showthread.php?t=75223

> Make sure the CPU data cache is enabled (it should already be)

Again not sure where to begin:
http://www.lmgtfy.com/?q=amiga+enable+cpu+data+cache
(maybe a more specific hint could help...)

> You could also try to find a cheap used Zorro II serial card. At least a few years ago
> they were relatively easy to find, due partly perhaps to people no longer needed them
> once they had broadband internet access.

Thanks for the suggestion - just a bit overkill to just backup my disks
(didn't think I'm going to dig so deep into this...)

> By the way, what make of CPU card do you have?

A2630

Heh. On the Amiga, for every byte sent/received to/from the serial port, the CPU gets an interrupt. With faster baud rates the Amiga gets thousands of interrupts per second. The suggestions I gave have the object of minimising interrupt response time, which could hopefully allow for more reliable data transfer at higher baud rates. Or at least, reduce the performance impact of the serial transfer on other programs you might be running.
Yes that should work. I use CPU-Control myself, which can also move the SSP; see below.
If you have some fast RAM on your A2630 and are running Kickstart 2.0 or later, the SSP probably already points to 32-bit fast RAM, so you won't need to do anything. To check, use CPU-Control:
CPU-Control SYSTEMINFO NOWIN
You want the SSP value to be larger than $00200000.

You could put a command like this in your startup-sequence:
CPU-Control VBR MOVESSP NOWIN
Not really. As you have a 68030 you can use the CPU program which comes on the Workbench disk; put
CPU FASTROM
into your startup-sequence to remap Kickstart to 32-bit fast RAM. (IMHO a better approach for your system would be to use ReKick to load a special Kickstart from disk, but I won't bother writing about that here. :))
The data cache should already be enabled by SetPatch which is run from the startup-sequence. To check, type SetPatch in a CLI window and it should say Enabled data cache.

Slightly off topic, but I remember using a parallel cable years ago to do that sort of stuff. It was a lot faster from memory.

@Mark:
Thank you very much for your answer
(but too much hassle and winter hollidays are over...)

@jb2515:
Any hints what kind of software you did use on Amiga and PC side?
(was it capable to create ADF-files directly on PC side or did you have to create the ADF on Amiga side and the just used it for transfering?)

Reason why I'm asking:
I have about 3000 disks here and if it takes me 3min for each one (with 57600bps serial connection) its not too much fun to play the diskjockey...