A3010 serial file transfer

[segasonic]

More useful info, thank you! If it has issues (which seems likely from the other thread) I can source an FTDI one later on.

[segasonic]

Using the hardware handshake hasn't made any positive or negative difference, it works fine at 9600 but at 19200 when receiving on the Archie I get 'Data subpacket is too long' followed by constant 'Bad data subpacket' and CRC errors.

The readme for David Pilling's SerialBuffer says:

As supplied, RISC OS, has serial input and output buffers of about 256 bytes.
Most communication programs will extend these, by loading a "buffer" module.
The reason for extending the buffers, is usually not so much that the program
can't keep up with the input data, as it may not get the chance. At 19,200 bps,
about 2000 characters per second may arrive. It is quite possible for
the time between polls to exceed a second.

The problem is that the conventional RISC OS 2 serial buffer modules are not
compatible with RISC OS 3 and later. Acorn have produced a module
"SerialUtils" which is supplied with RISC OS 3. Loading this before running
a comms program allows it to work. However, SerialUtils simply prevents the
buffer module from doing anything. You might as well not bother loading the
buffer.

Under RISC OS 3 and later, there is a better way of implementing extended
buffers, using the buffer manager.

Here then, is a buffer module for RISC OS. It will default to a 2K output
and 16K input buffer.

There are two *commands;

*SerialBufferSize <input> <output>

this sets the size of the input and output buffers.

*SerialBufferShowSize

this prints out the sizes of the input and output buffers.



As usual, the buffer should be RMLoaded in the !Run file of your comms
program.

It says the SerialUtils module (that I don't know how to add, I guessed but I don't know if it's working) stops the buffer module from working. His module will fix it but I don't know how to load that either, I guessed again but it just triggered an OS error.

That said, I have no idea if that's anything to do with my issue anyway

[BigEd]

Is there a way to set a high water mark? The principle of turning off the tap is to turn it off in good time, before the bucket overflows. These USB serial adaptors send more bytes before responding to the flow control. It's not the size of the buffer so much as the managing of it.

That said, maybe on the PC end you can pace the output, and run at a higher baud rate and get a higher effective transfer than if you didn't.

[segasonic]

There doesn't seem to be such a setting, both ends are fairly sparse in config options. I'm transferring a few games over at the moment, the slow speed isn't so bad if you've got other stuff to do like explore Arculator. ~45 minutes for two megabytes would have been considered fast at some point

[segasonic]

New cable arrived today, it's a StarTech ICUSB232FTN with FTDI chipset. It works perfectly with hardware flow control. 38400 baud seems to be the sweet spot, it's still stable if I go up to 57600 but not any faster.

About 50 minutes to transfer 10MB instead of three and a half hours with the Prolific chip! It's a crossover as well so I don't need to chain cables.

Thankfully I can return the other one so I've lost nothing and gained some experience.

I've been trying to learn more in the meantime, I've got uniboot set up and starting to get my head around how it works. Also gave in and got a parallel Zip drive so I can make backups.

Sincere thanks again to all who gave help and advice

[richw]

Another consideration could be the screen mode on the A3010. If you flip into mode 0 then you may be able to crank the baud rate higher.

[segasonic]

Another consideration could be the screen mode on the A3010. If you flip into mode 0 then you may be able to crank the baud rate higher.

Thanks, I'll give that a go. I don't know what mode it defaults to, it's set to auto I think. I'm just running over RF to a Trinitron CRT at the moment, haven't got a SCART lead yet.

[philpem]

Another consideration could be the screen mode on the A3010. If you flip into mode 0 then you may be able to crank the baud rate higher.

Thanks, I'll give that a go. I don't know what mode it defaults to, it's set to auto I think. I'm just running over RF to a Trinitron CRT at the moment, haven't got a SCART lead yet.

Probably 25 or 27 if you have a VGA monitor connected. VGA 640x480. Probably 16 colours which would be mode 25.

[segasonic]

Probably 25 or 27 if you have a VGA monitor connected. VGA 640x480. Probably 16 colours which would be mode 25.

Not VGA, I'm using the modulator. Loads of noise on the grey desktop background but it's not actually that bad for gaming! It does look like a 16 colour desktop though. The Trinitron is just a TV with RGB, good for retro gaming but not high res.

I'll get a SCART lead, or I might try one of those mini VGA to HDMI adapters - I've got an HDMI panel next to me but the CRT is at the other end of my office, so the way I'm set up at the moment for tinkering isn't easy on the neck

[segasonic]

Another consideration could be the screen mode on the A3010. If you flip into mode 0 then you may be able to crank the baud rate higher.

Mode 0 gives me about 500 bytes of extra bandwidth, topping out at just over 4kB/s. Good tip!