Workbench 3.1 Increase Serial Port Speed Options?

[ahandyman59]

I have been looking for several hours and have not yet found an answer to something I am certain others answered years ago...

Using an A2000 with a 68030 25mhz (a2630) accelerator, 1m chip, 8m fast memory

The amiga serial port settings gui goes 19200, then 31250 and that's it. I hear about people getting reliable connections with 56k even up to 115k. I'd settle for 38400, etc. Anything above 19200.

is there some kind of serial port configuration tool someone has put together that handles higher "serial rates"? If there is a manual way to tweak some file, I'm game, but all I'm seeing is binary configuration files...

How are others accomplishing these higher rates with amiga explorer?

[thomas]

Serial prefs on the Amiga only apply to the SER: DOS device. Apps using serial.device directly usually have their own way to configure the serial speed.

The same applies to AExplorer, too. Serial prefs are ignored. AExplorer is configured by tooltypes or command line arguments. If you run AExplorer from Workbench check icon information. You can set serial speed as text.

Anyway 38400 probably is the maximum you can get from the Amiga's serial port. For higher speeds you need at least a different driver (like 8n1.device or baudbandit.device), most likely you need a Zorro expansion with better serial ports.

[Misclegend]

Originally Posted by thomas

Anyway 38400 probably is the maximum you can get from the Amiga's serial port. For higher speeds you need at least a different driver (like 8n1.device or baudbandit.device), most likely you need a Zorro expansion with better serial ports.

nope
the serial speed in the AMiga depends of cpu power
in Aexplorer I have configured it to 115200 in both computers and file transfer works at such speed
this is on A1200 + 020/28mhz which is aprox the minimum cpu to work at 115200

in the case of OP a 030/25mhz is enough to work at 115200

8n1.device or baudbandit.device are very old buggy and don't work wirh Aexplorer

[ahandyman59]

Thank you for your assistance! Because of you guys (and me going back and RTFM for AExplorer), I figured out how to adjust the AExplorer parameters on the Amiga side. On the PC Side, it requires not only tweaking of AExplorer on the PC, but it seems to need the actual Com port settings on the PC to match the AExplorer software settings. If all the 3 pieces were (PC AExplorer, Amiga AExplorer and the PC Com Port settings) match, it works.

That said, I have been unable to get reliable transfers above 19200. A file starts then stops in a few seconds, or the AExplorer UI on the PC starts giving communication errors. I did try the 8n1.device at 38400, but it is inconsistent and never works with multiple files. Always stops prematurely. I suspect the best way to do this may indeed be to get a zorro based IO expansion card. If I go the route of an IO card, is TCPIP faster than a GOOD serial port? I'm guessing yes?

[thomas]

If you have a Zorro-based Amiga IMHO the better would be to get an Ethernet card (like X-Surf for example). This way transfers would be much faster than over serial and yourwouldn't be limited to Amiga Explorer but could use FTP, SMBFS and the like. Not to mention connecting directly to the internet.

[Misclegend]

Originally Posted by ahandyman59

Thank you for your assistance! Because of you guys (and me going back and RTFM for AExplorer), I figured out how to adjust the AExplorer parameters on the Amiga side. On the PC Side, it requires not only tweaking of AExplorer on the PC, but it seems to need the actual Com port settings on the PC to match the AExplorer software settings. If all the 3 pieces were (PC AExplorer, Amiga AExplorer and the PC Com Port settings) match, it works.

That said, I have been unable to get reliable transfers above 19200. A file starts then stops in a few seconds, or the AExplorer UI on the PC starts giving communication errors. I did try the 8n1.device at 38400, but it is inconsistent and never works with multiple files. Always stops prematurely. I suspect the best way to do this may indeed be to get a zorro based IO expansion card. If I go the route of an IO card, is TCPIP faster than a GOOD serial port? I'm guessing yes?

there is no need to add a zorro serial card
Amiga explorer works at 115200 through the normal A1200 serial port

perhaps you are using some unregistered/bad cracked Amiga explorer?

plz note they limit the speed if not registered correctly

[nogginthenog]

Screen depth affects serial speeds. Less colours = faster.

[zipper]

Yes and RTG frees bandwidth - my A4000 did 115200 fine under RTG graphics and 060 accelerator. Anything more got into troubles.

[hooverphonique]

Originally Posted by nogginthenog

Screen depth affects serial speeds. Less colours = faster.

That should only be the case on Amigas without fastram.

[ahandyman59]

Misclegend: I purchased Amiga Forever Premium and have a legitimate license, legitimately installed with the license key. That is not the problem.

You guys can argue all you want, but for the sake of knowledge, I set my a2000 to low rez not interlaced, and 2 colors, then restarted it. AExplorer now reliably and consistently works at 38400! It's weird and doesn't make much sense to me, but it does indeed work. It definitively does not work at higher resolution modes, but does in lower ones. I'm going to try middle resolutions and see when the slowness breaks 38400 connection speed. Does interlace mode use more cpu cycles than non-interlaced? I hope to find out soon...

Again, this is an A2000 with a CBM A2630 running at 25mhz, with a 1mb Fat Agnus, a super denise and 8 meg of fast memory from a CBM a2058 RAM card.

For the record, I am a tech "geek" and have been a software developer/tester (in the aerospace industry) for nearly 40 years. I am methodical and reliable in my testing methods.

[ahandyman59]

Followup to my testing works in high rez with 4 colors fine. If it's changed to 16 colors it does not work.

Side issue.... What/how is super high rez used? I have a 4k monitor attached to my amiga and even with that very high rez monitor, in super high rez, everything is very blocky, to the point of being "uncomfortable to read"... Is there a way to get the fonts to look nice in super high rez mode?

[ahandyman59]

Does work with 8 colors too, just not 16 colors or in super high rez mode. This sort of makes sense. The more colors, the more data per pixel needs to be sent.

[Daedalus]

Short answer: The internal Amiga serial port is CPU driven and has no buffer, so it requires very rapid and frequent interventions from the CPU every time a single byte is sent or received. This means that anything that reduces the available CPU or bus time can cause issues with serial. Some programs might cope better than others by using robust protocols, so you might find that some programs work at 115,200 baud while others don't.

On the Amiga, the more colours used, the more time with the chipset in control of the bus is needed, leaving less time available for the CPU, and the same with the resolution. AGA Amigas have faster chipset buses so are better able to deal with such colour depths and resolutions using less bus time. Additionally, if there is any software running that places a heavy load on the CPU, it makes it more likely that the CPU misses one of the few bus slots available, meaning serial transmission errors are more likely.

Bottom line, everyone will have different results here - just because someone gets 115,200, doesn't mean everyone will. 57,600 was what I tended to find as the fastest speed that would work reliably on stock Amigas, but I could use 115,200 on my accelerated A1200 if I didn't stress the CPU. Additional serial ports dramatically improved that situation - a HyperCOM board let me run at 115,200 solidly and reliably, regardless of colour depth and CPU load, and could even run at 460,800 (though very little else could use that speed except other HyperCOM boards).

[Etze]

Originally Posted by ahandyman59

Again, this is an A2000 with a CBM A2630 running at 25mhz, with a 1mb Fat Agnus, a super denise and 8 meg of fast memory from a CBM a2058 RAM card.

Wait, do you even have RAM on your A2630? Zorro-II-RAM (A2058) is really slow.

[hooverphonique]

Interesting - I wasn't aware that DMA load would affect custom register access/interrupt latency when running code from fastram - or maybe I just didn't remember

[Toni Wilen]

All custom registers (which includes serial port and interrupt registers) unfortunately have exact same CPU access speed limits as chip RAM. Without it this problem would not exists if system has Fast RAM.

[Misclegend]

I just tested in my A1200 if screen modes or color depth affect the serial transfer rate and I found that works at 115200 even in pal 640x512 in 256 colors
but usually I use a workbench in 32 colors

When transfering data from PC to Amiga I can't do anything other thing because the cpu in my A1200 is 100% busy
I have a tra1200 turboboard 020/28mhz btw, is a bit faster than the 030/25hz which OP have


Now in the PC I use a USB > serial adapter because my motherboard do not have a normal serial port
in the Amiga I'm using OS3.9 and serial.device V 43.6 which comes with it

[ahandyman59]

@Etze The A2630 I have has 2mb ram on it. No daughterboard attached (yet)...

[patrik]

CPU fastrom to move kickstart into 32-bit memory on these boards makes a large speed difference.

Btw, I would recommend buying the ZIP RAM chips to get it up to the full 4MB 32-bit mem.

[Misclegend]

A: The pre-configured default is 19.2 kbit/sec, which was tested to work well even on the slowest systems (68000 CPU). We have successfully tested settings of 57.6 kbit/sec on Amiga 1200s (68020 CPU), and up to 115.2 kbit/sec on Amiga 3000 and 4000 systems (68030 and higher CPUs), using the standard Amiga serial port and the standard Amiga serial.device.

The performance of the Amiga serial port may be reduced depending on the resolution and depth of the frontmost screen. On older Amiga systems this begins to be noticeable when using Amiga screen modes having more than 8 colors. RTG (graphics card) modes have no negative impact on performance.

For better performance, the Buffer Size in the Amiga Serial Preferences should be set to at least 4096 bytes. Lower values can cause transmission problems at higher speeds, or, on 68000 Amiga computers and Workbench 1.2, even at the default speed.

it seems the minimum cpu for 115200 speed is a 020/28mhz or 030/25mhz
but they do not tested it on the Amiga 2000

OP try this

We recommend an initial increase from the default value of 512 bytes to 4096 bytes.

On the Windows side right-click the Amiga Explorer icon, select Properties, click the Options tab, then set the desired value (e.g. 4096) in the Packet Size field.

On the Amiga side click the "AExplorer" icon once and select the "Information..." (or "Info", on older systems) item from the Workbench menus, then edit the PACKETSIZE ToolType entry (e.g. set the value to 4096), press Enter and click Save.