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Kermit-80 for Kaypro -- XP tansfers

T

tezza

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Joined
Oct 1, 2007
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Hi again,

Still working on getting this Kaypro locked and loaded.

I managed to get Kermit-80 on the machine. This is a desirable step as I don't want to drag out my MSDOS machine everytime I want to get an Internet-sourced file into the Kaypro.


However, I'm having some issues with it regarding file transfer. I've tried downloading a file from the XP machine to the Kaypro using hyperterminal (Kermit protocol) to find it seems to suddenly stop the transfer at about 16K. This is despite:
  • the speed selected (i've tried from 300 to 9600)
  • any flow control being selected (or not)
  • the fact that the kermit buffers are at maximum size
The crash seems to happen when the Kaypro is doing a disk write. Transfer pauses. Hyperterm pauses..then seems to resume but then throws up a message that there is too many errors. Xoff/Xon doesn't seem to make a difference. It's almost like the Kaypro tells hyperterm to stop...hyperterm does....then it tells it to start again...hyperterm does but that kaypro is not actually ready (it's still writing to disk). Errors result until hyperterm terminates the transfer.

Anyone else come across this? I've tried the XP hyperterminal alternative "Tetra Term" but that was even worse!.

Tez
 
Much appreciated Ziloo but I'm aware of that site. In fact, that is where I got Kermit and the documentation from.

If I can't crack the problem I might have to look at zmodem or another protocol.

Tez
 
ziloo said:
Tez,

Kermit is a fairly bulletproof communication software. Are you sure that
the serial IO hardware on the Kaypro side is working properly? Have you
done a loopback test to see you can send and receive properly on the
Kaypro side?

Thanks to you I found this link for a general discussion on serial
communication:

http://www.siongboon.com/projects/2006-03-06_serial_communication/

ziloo
Click to expand...

I haven't but the serial communication seems to be working. Terminal mode works just fine. During file receive the Kaypro seems to receive packets ok up to about 16k. Halfway up to this there is a small disk write which the system handles. I assume the Kaypro is clearing the 8k buffer. Hyperterminal stops sending for a moment then resumes. However at about 16k there is a longer disk write on the Kaypro. Hyperterminal pauses and comes up with a timeout message. However when the disk write finishes, it appears to resume sending? A few packets are sent, the Kaypro seems to write to disk again (just a small one this time) but this second disk write is enough for hyperterminal to give up. It just stops with the message "Error limit exceeded" (or something like that).

I can't find any way to tweak hyperterminal's error limit. It seems hardwired.

I thought this was simply a speed issue, but 300 baud shows the same symptom. Actually not quite...at 300 baud the transfer stops even earlier??

I haven't tried a smaller file yet to see if the system can actually close the transfer properly. I'll do that tonight.

Has anyone successfully transfered large files to a Kaypro II using kermit and hyperterminal with Windows XP? If they have, then the problem is with my system somewhere. It could even be the BIOS com port settings maybe?
 
I've found a serial port sniffer program to be extremely useful debugging this sort of thing. You can see the bytes going back and forth.

Down the track I'd like to get kermit working for the N8VEM and the Propeller Z80 emulation. But I've recently even had problems with xmodem. Xmodem is about as simple as it gets, and I've got the assembly version plus also a version working in vb.net and half (the send part) working in sbasic. It is a huge advantage to be able to have the source code and to put in breakpoints when things don't work. I had to do this recently when wireless stopped working properly when transferring big .com files. Worked fine with text files. The solution there was to buffer everything into a 131 byte array and send it out as a group. So if xmodem needs tweaking to get it to work, the kermit with its more complex protocols might need more tweaking. The problem turned out to be reading files in the middle of sending packeets and adding delays, and this sounds strangely like your problem too.

Do you have xmodem working?

And do you have a serial port monitor program? (I got one when it was free but I see on the website it is now $11). ? pay the money, or PM me and I could send over a copy of the older version (which works fine).
 
Hi,

No, Kermit is the only comms package I've tried so far. However, if I can't get any joy with it I'll certainly give Xmodem and Zmodem a go. I'll persist with kermit for a little while though, as to get the other two on a floppy involves dragging out and wiring up the MS-DOS box again (and unpacking/unsqueezing) the files.

I sniffer would be great. PM sent.

Tez
 
I'll be at work for a while longer but when I get home I'll see what I have. I'm thinking if you can get anything under 16k to work, you could send a compiled version of xmodem over with the code you already have working? xmodem needs two values - the port address for an in/out (usually the same number) and the port address to check if a byte is available. Do you have these values? If so it should be possible to recompile a new version of xmodem quite quickly. Addit: I thought I would look up the port numbers in the technical manual http://www.retroarchive.org/docs/index.html but the values are in section 16 and the manual I found only seems to be scanned to section 14. Addit, Addit: Found the complete manual here http://www.bitsavers.org/pdf/kaypro/1484-D_KayproTechnicalManual_Dec84.pdf Not sure if it is the same model, but the info is in section 16.4 port 4 and port 6 I think are going to be the relevant values. Re testing the bits, I have a feeling the values for the n8VEM are 32 and 33 to test if a byte is available. I think this means bit 0 is changing, so hopefully it is the right way round as the kaypro seems to test bit 0 of port 6. So might not need too many code changes for xmodem.
 
Last edited:
Dr_Acula said:
I'll be at work for a while longer but when I get home I'll see what I have. I'm thinking if you can get anything under 16k to work, you could send a compiled version of xmodem over with the code you already have working? xmodem needs two values - the port address for an in/out (usually the same number) and the port address to check if a byte is available. Do you have these values? If so it should be possible to recompile a new version of xmodem quite quickly.
Click to expand...

I don't have them at hand but I'm sure I can find them somewhere.

Tez
 
Tez,
I have found Hyperterminal to be a very poor program for vintage interfacing. Usually it
requires a reboot, of windows, to change port settings. Xmodem totally wouldnt work for
me with a vintage machine. I found it better to have a dos machine with Procomm or
similar. I still have not found a windows terminal program I am happy with.

Bruce
 
Thanks for those comments Bruce,

I'll continue trying things...and maybe look for other windows solutions too. My XP unit feeds all my other vintage machines ok. I just have to find a solution that works for the Kaypro. Trial and error might do it. Anyway, I'll experiment and report back.

Tez
 
It's working!

It's working!

Ah ha, cracked it!

The problem was with the receive BUFFER-SIZE. According to the docs, this can be a value from 1 to 64 (1 = 128bytes and 64 being 8K). The default was 64 (8k) and I’d left it at that as I figured the bigger the buffer the better, right? In fact, I thought maybe the buffer was too small! Not in this case. I halved the buffer size and suddenly everything worked. I even took it down to one (at 19200 even!) and it still worked, albeit transmission was a little slower.


So now, everything is peachy. I can transfer files of whatever size at 19200 baud from the XP Windows machine to the Kaypro II using Hyperterminal whenever needed.
I’m happy. I’m also very impressed with Kermit-80. It’s easy to use with a comprehensive but understandable command set.


Playing around with this Kaypro has been fun. Setup is daunting to a newbie what with having to first of all uncrush and unsqeeze files, unpack libraries, create HEX files from ASM files and then using DDT or MLOAD. Gawd! Then there is the strange three character file extension to use when assembling which actually isn’t a file extension at all but rather a series of switches?!


Yet in some masochistic way it’s all very satisfying! Is that weird or what??


Tez
 
tezza said:
Ah ha, cracked it!

The problem was with the receive BUFFER-SIZE. According to the docs, this can be a value from 1 to 64 (1 = 128bytes and 64 being 8K). The default was 64 (8k) and I’d left it at that as I figured the bigger the buffer the better, right? In fact, I thought maybe the buffer was too small! Not in this case. I halved the buffer size and suddenly everything worked. I even took it down to one (at 19200 even!) and it still worked, albeit transmission was a little slower.


So now, everything is peachy. I can transfer files of whatever size at 19200 baud from the XP Windows machine to the Kaypro II using Hyperterminal whenever needed.
I’m happy. I’m also very impressed with Kermit-80. It’s easy to use with a comprehensive but understandable command set.


Playing around with this Kaypro has been fun. Setup is daunting to a newbie what with having to first of all uncrush and unsqeeze files, unpack libraries, create HEX files from ASM files and then using DDT or MLOAD. Gawd! Then there is the strange three character file extension to use when assembling which actually isn’t a file extension at all but rather a series of switches?!


Yet in some masochistic way it’s all very satisfying! Is that weird or what??


Tez
Click to expand...


Just to clarify... the recieve buffer size on Kermit?
Glad you were able to get this working! I will keep it in mind once I attempt something similar.
 
leeb said:
Just to clarify... the recieve buffer size on Kermit?
Glad you were able to get this working! I will keep it in mind once I attempt something similar.
Click to expand...

Correct. The buffer size setting in kermit on the kaypro.
 
Fredbug said:
Tez,
I have found Hyperterminal to be a very poor program for vintage interfacing. Usually it
requires a reboot, of windows, to change port settings. Xmodem totally wouldnt work for
me with a vintage machine. I found it better to have a dos machine with Procomm or
similar. I still have not found a windows terminal program I am happy with.

Bruce
Click to expand...
Depending on circumstances I use Hyperterm or Procomm/Telix in DOS, but have never found a problem with Hyperterminal; maybe you didn't realize that you have to call/disconnect in order to change the port parameters?
 
Yes I do disconnect. most of the time changes in baud, or other settings
require at least a program exit/restart for me to get them to work.
Could be my machine, but it is annoying if you dont know the
settings of you vintage thing to start with. Procomm is much better.

Bruce
 
Fredbug said:
Yes I do disconnect. most of the time changes in baud, or other settings
require at least a program exit/restart for me to get them to work.
Could be my machine, but it is annoying if you dont know the
settings of you vintage thing to start with. Procomm is much better.

Bruce
Click to expand...
Can't say I've ever had that problem, but yeah, if you're experimenting then DOS and Procomm or Telix, or even one of the more flexible Windows terminal program is the answer, but if you're doing routine transfers then HT does a pretty good job and it's usually available.
 
Hi,

Strange. That link works for me. In fact I obtained Kermit-80 from that exact site.

Try again. There just might have been a glitch on the net when you last attempted access.

Tez
 
tezza said:
Ah ha, cracked it!
Click to expand...

Great work Tez.

That provides another option for me to transfer files from my Kaypro II to XP/98 box, without the need to reboot my XP box into 98 in order to write 5 1/4" floppy disks.

Very good, thank you.

Philip
 
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