#MultiTasking during d/ls
28 messages in this thread
When I'm downloading files using Jr-comm 1.02a, and I do other stuff on the
computer (copying files or editing text etc..) I end up with a corrupted file.
Sometimes there will be errors in the download, or it simply doesn't see them.
So, right now, to insure my downloads work fine, I don't multi-task during the
downloads.
I'm using a 68000 machine, and was wondering, if I had an accelerator (say a
68040) would the computer be working fast enough that I could multi-task during
a download without causing errors in the file?
It all depends. Do you download to a hard disk? If so, what hd
controller are you using? Is it DMA? What baud rate do you normally use?
Are you running 1.3 or 2.0?
-sja
I almost always download to RAM:, but I haven't noticed any differences to
whether I d/l to ram or the HD, but I still do it in RAM:. I'm using a GVP
Series II SCSI controller. I have no idea if its DMA or not. The speed
between the computer and modem is set for 38400, and I usually connect at
14,400 and have a cps rate of about 1600. I'm also running dos 2.0, and it's on
a 2000 with a 386 BB installed.
I've noticed that if I go above 38400 baud I get erros in the transfers.
Now if I accelerate my amiga… it will be with a Zeus 040 and that will become
my HD controller too.
Any ideas? Thanks for your help
Shane,
You should not be dropping characters or getting excessive errors. Try this
..
Go into prefs/serial and set the buffer size to 2k. Make sure RTS/CTS is set
(and that you've got a "7 wire" modem cable that supports those lines). Set
your DCE speed to 19200 instead of 38400 (you say you're getting a cps of 1600,
so you don't need the bandwidth beyond 19200).
I remember something (from a long time ago and a place far, far away) about
some GVP scsi host adapter. Something about writing to disk and serial at the
same time causing problems … they had a software patch solution (something
like breaking down big disk writes to a bunch of smaller ones). You might drop
over to their section in AmigaVendor if the above suggestions don't help.
Steve,
I do have a 7 wire modem cable, and I'm using RTS/CTS and I have the buffer
size set to 65k. I suppose I could use 19200, but I was using 19200 until
about last week, and I always had the same problems at 19200 as I do at 38400.
Going up to 57600 though, is too far and I start loosing characters then.
I'll have to pop over to GVP and see what they have to say about this. Maybe
there's a patch I should have?
Kind of dissapointing when I'm showing off my amiga to a PC user about how I
can continue to use the computer during a transfer, and then the zip files are
corrupt, hehe 🙂
Thanks for your help
Your buffer size is far too large. Set it to 2k-4k.
Shane,
I too use JrCom 1.02a, running the serial port at 14400 on a stock
68000 is really pushing the limits of the cpu! Try upping the task
priority of JrComm. to 7-9. That should help. I am using a 68030 and
still try not to multitask during downloads, when the machine has to
switch between tasks and the serial port is still recieving data at full
speed, your just asking for lost bits!
IMHO
…Steve
====>>> Motorola 68030 Inside <<<====
Steve,
How do you change the task priority of different programs etc? Thanks for your
help 🙂
Shane,
In menu `Options-General' that will bring up a wind and in the upper
right hand corner is a box labeled Task Priority, set this up to the
desired level (actually a little experimentation is needed) then save your
configuration.
Get back to me and let me know how it works out. I have my task
priority set to 10, but then I do not do any multitasking other than what
is resident, during downloads to ram: but I get speeds up to 1700 cps with
my USR Courier HST on compressed files and have gotten over 2400 cps on
text.
…Steve
====>>> Motorola 68030 Inside <<<====
Steve,
Thanks, I didn't know it was in the program itself where I had to change the
task priority. Here I was looking through the DOS manual for some command,
hehe. My priority is presently set for 0, I suppose the higher it is the
better? And just how high does it go? Anyways, I'll let you know how this
works out.
Shane,
I think tha JRCom will only go up to a task priority of 10. You
never want to go much higher that that on any task anyway. If you do
you can shut out things like writing to the hard disk, accepting
input form the keyboard, and keep the cpu from doing vital things
that it needs.
For a little more understanding of tasks and thier priorities download
Steve Tibbits TaskX (it's here in the libs somewhere). It will show you
all the task running and what DOS has their priority set to, and allow you
to play with it some. There are some things you absolutely want to leave
alone though ie console.device, input.device, all the drive handlers ect.
but it is kinda interesting to see what the computer is doing behind the
scenes!
…Steve
====>>> Motorola 68030 Inside <<<====
I have a 68030 machine, and I get errors while downloading at 2400 bps! It
happens with both Term and JPTC; I never noticed it with JR-Comm. I don't get
corrupted files, but I end up exceeding the maximum number of errors if I'm not
careful.
Using BaudBandit.device instead of serial.device takes care of the problem, but
I can't imagine why I'm having it in the first place!
Hi Jim,
Guess I'll have to find this BaudBandit.device and give it a try instead. Any
ideas where I'll find it? I suppose I should check the libraries.
Thanks for the info..
There is also the ARTSER.DEVICE, which like Baudbandit.device may be more
functional than the native Amiga serial.device. However, serial.device is
much improved in Workbench 2.1 and I don't use the alternatives any more.
I have 2.1, and I still have to resort to BaudBandit.device at 2400. I have
artser, but I haven't tried it yet.
BTW, for Shane, I don't know if BaudBandit.device is on Compuserve or not. If
you look, be sure not to get the terminal program called BaudBandit by mistake
(or is that a commercial program? I can't keep track of everything…)
There is absolutely no reason you should be getting downloading errors
at 9600, much less 2400, using 2.0+, regardless of your cpu, unless
you've got hardware problems or inefficiencies (non-DMA harddrive
controller on a 68000 based machine) or you've got your prefs/serial
buffer set to higher than about 4k, or you're on a non-AGA machine
sucking up all the DMA bandwidth with an 8+ color workbench (or your
term program is using 8+ colors).
-sja
I suppose I'm sucking up all of the DMA, since I'm using 8 or 16 colours on a
non-AGA machine. I also had the buffer set too high, although I don't
understand why I shouldn't set it higher than 4k?
I have an A3000, my terminal program is always using 16 colors but when the
problem happens it can happen even if my terminal program's screen isn't in
front — and although my WB is 8 colors interlaced now, when I started out it
was only 4 colors non-interlaced and still the problem shows up. I'm honestly
not sure what I have the serial buffer set to. I'll have to check it.
Jim,
I've got a GVP IOExtender in my 4000 (previously in my 3000) with 2 14.4k
modems … one on the IOExtender and one on the internal serial port. There
are many times (at least once a day) where I will have both modems transferring
files simultaneously — usually running AP on one and VLT on the other. I do
not, on the 4000 nor the 3000 previously, drop characters, or have excessive
errors (if I get 1 error in 1000 blocks it is rare), or have low cps rates
(average is 1550-1660).
If you are having the type of problem you describe it is more than likely due
lack of dma bandwidth (a 16 color screen on a 3000, regardless if it is in
front or not, is a good candidate for the cause), a bad configuration problem
somewhere in prefs/serial or with your modem, or a hardware problem
(intermittently bad solder joint somewhere, cracked serial cable, etc.). There
is an explanation somewhere because the Amiga is very capable of performing
telecomm without the problems you are having.
Shane:
I have a 14.4K modem on an 25 mhz, '030-equipped A2000 with WB 2.1 running
an 8-color Workbench, and am easily able to multitask, whether I'm
downloaded to a ram disk or to hard disk. I've had transfer rates as high
as 1,700 cps using a large serial port buffer and hardware error
correction. I've even been known to play a re-entrant game while
downloading, or work in Final Writer.
The amount of free ram you have is, of course, a factor.
GVP boards apparently are funny at tasks like this. I have heard there are
patches or kludges to solve that problem if you have it.
I just helped a friend with a brand new 486 set up his Windows system for
modem use, and believe me, you are giving away nothing to your PC friends
when it comes to modeming. Many, many problems with hardware/software
conflicts. Remember, too, that with the 68000 you're running an Amiga that
has perhaps the processing power of a fast 286 or slow 386. Windows won't
run well at all on those level machines, much less let you multitask while
downloading. You probably could go to 9600 bps reliably on your 68000
machine and still multitask some things but doing same with 14.4K is
beyond its means.
Another "notable" here is to set the task priority a little higher on your
terminal than the other programs you may be Multitasking. I keep Terminus at
"2", and don't have a problem on my NO FAST A1200. I'm also running 16 color @
19.2 serial thru Terminus (32.??? via serial preferences) and a 14.4 modem. I
have no problems, and average about 1650-1700 on my uploads, and vary on my
DL's (Which are generally governed by "they who send" and their ability to send
it at acceptable speeds.)
I digress however…. I couldn't go past 19.2, 4 colors, on my FAST ram equiped
A1000.
Chris, I am running Terminus on my 25 mhz A3000. I have a 14.4 Boca modem and I
have no problems d/l on other boards here in Houston, but when I try to d/l on
the 14.4 CIS lines, I get mega-errors and sometimes the server terminates the
tranfer. It reports "too many NAKs" I think. I don't have this problem on CIS'
2400 lines. Have you, or anyone else, experienced these problems?
No, but I use the 800 to dl in 14.4, and a regular number out of Memphis the
rest of the time. I have had problems twice now where CI$ sends me some
cryptic "Lost Network Connection – Data may have been lost" message, which in
effect wipes about about half of what I was typing.
The difference in 2400 lines could be two different things… a cleaner line,
or the lower speed may make hacking out the error correction alot easier, which
you won't see alot of. However, in retrospect, I hardly ever get errors (other
than timeout) on my AT&T… it just gets spastic as it tries to correct the
packets.
"spastic modem"?
ROTFL
//daniel on autopilot in paradise
\X/ powered by intel and motorola
Have you contacted FEEDBACK about this?
//daniel on autopilot in paradise
\X/ powered by intel and motorola
I couldn't tell you how many times I've contacted feedback about this. However,
I found the answer here. My i/o buffer was set too high and my task priority
was set too low. Also, I dropped the serial port's baud rate to 19200. That
seemed to do the trick!
Just when you think you understand how the electron(s) flow(s)….
I have been running with my serial preferences input buffer set to
maximum, as well as the baud rate, for some time now and have had no
problems.
(daniel scratching his head and muttering something to himself) Well, if
that's what works for you, then it must be the right answer.
Glad to see that all is working as intended and desired.
//daniel on autopilot in paradise
\X/ powered by intel and motorola