Maximum speed of the internal serial port?

[orange]

iirc (stable) 38400 is maximum on 68000. baudbandit and others claimed 57600 but it simply isn't possible. use the parallel port if you can.

[prowler]

Originally Posted by Sandro

speed of the amiga serial port depends of the cpu
my A1200 020/28mhz is capable to transfer at 115200 in amiga explorer

but if I remove the turboboard of my A1200 is only capable of 38400
so basically for the max speed 115200 you need a 020/28mhz or a 030/25

Very interesting, thanks. I'll try to achieve that on the next occasion I use my AE link (the A1200 is now '030 accelerated).

Edit: Is that with the standard serial.device driver?

[source]

I thought the Serial port (at least on the 2000 / 500) would not work reliably once you exceed 38400 - I had a VXL030 board and 32bit ram and going past 38400 would get transfer errors.

[Mad-Matt]

I had no issues using 115200 with my 030/33 card on A1200 using artser.device. Maintaining that speed for downloading/browsing was quite taxing though as you see the AmigaOS feel slightly sluggish. 040/25 was much better, although I did upgrade to a twister MkII eventually that allowed connecting to the modem at 230400 and allowed 6-7 kb/s downloading files on a good day! and no slowdown at all in AmigaOS. The Serial port was still used to route the internet to the pc via nullmodem and miamideluxe

[zipper]

Using RTG lets the original chipset do 115200 even on 500/2000 with an accelerator.

[pandy71]

Amiga use MC1488/1489 TTL to RS232 voltage translators - those devices are very old (half 70's) - they speed will affect fast transmission (they are designed for typical speed bellow 19200bps) also they are sensitive for cable (capacity). For higher transmission speed they need to be replaced by modern, fast voltage translators for example http://www.exar.com/connectivity/transceiver#rs232

[Sandro]

Originally Posted by prowler

Very interesting, thanks. I'll try to achieve that on the next occasion I use my AE link (the A1200 is now '030 accelerated).

Edit: Is that with the standard serial.device driver?

yes using serial device from OS3.9
also I tried 8n1.device but not worked fine....in fact if you read AE docs they say that program only works or was only tested using serial.device

[Hewitson]

Originally Posted by droopy

I had 4 56k modems answering my bbs in the late 80ies..

Can you please share the schematics for your time travel machine?

[voyager]

Originally Posted by Hewitson

Can you please share the schematics for your time travel machine?

I think he means the late 90ties

[desiv]

Originally Posted by voyager

I think he means the late 90ties

Yeah, for 56k..
Although, unless you had digital lines and digital 56k modems, a standard 56k modem wouldn't "answer" a standard phone line and connect to another 56k modem at 56k.

I think the fastest you could get over POTS to POTS was 33.6k.
(And even 56k digital backend was 33.6 up and 53.3k down best case)

When transferring back/forth to my A1000 over serial for transwarp disk images, the fastest I've safely and consistently done is 19,200.
I think I had some success with 2 bitplanes and baudbandit.device at 33.6k, but if I did, it was really inconsistent because I ended up going back to 19,200.
For some reason, 28.8k didn't work for me at all (had better, but not consistant luck with 33.6k) when trying transwarp.

Of course, now I use AmigaExplorer over Ethernet to the A1200 (or I ftp the image from my PC to the 1200 and just write it out).

desiv

[hypnoshock]

Dredging up an old thread but A500 with terrible fire 030/50mhz can only seem to handle Z-Modem transfers from minicom (in Linux) at 19200. Anything above that will get a 'hardware buffer overrun' error in Term 4.8. I have tried the same setup with my A1200 030/25mhz and that can reliably transfer files without an error at 38400 (possibly higher).

Enabling hardware flow control (RTS/CTS) does stop the errors so I guess the Amiga will be periodically telling minicom to hold fire whilst it processes the bytes so there's some HW bottle neck other than CPU I think. I've got my screen colours down to 4 but I'll try at 2 and see if it pauses less frequently.

So the transfer rate being down to just CPU speed can't be entire true.

Also tried saving the file to RAM: just in case it was a bottleneck with writing to the CF.

[zipper]

Get a RTG card for your A500 so GFX isn't hogging your cycles That's why I got 115200.

[utri007]

Plipbox is easy solution for this.