Author Topic: A Question about file transfer from PC to PCW  (Read 904 times)

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Offline zamuel_a

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A Question about file transfer from PC to PCW
« on: 23:23, 11 August 17 »
After some grateful help on this forum I got my PCW 8512 working. I did some tests with the RS232 interface I have and was able to transfer some stuff from my PC. I use Kermit on the PCW and after a lot of research I found out that I need a terminal software on PC that handles the Kermit protocol. I found the program "Tera Term" and with that I was able to transfer some binary files. I first tried some other terminal program but hadn't any success. Maybe in Kermit you can change so it can handle more modern protocols?

I found a lot of software for the PCW that were in .DSK format. I understand I need DSKWRITE to convert it from that file and to a real disk. I tried to send one file but after it sent about 15% I got a lot of retries in Kermit and after a while a message that it didn't work. It happened with several files and I wonder if it's because the file is to big for the disk or anything like that? Ok if it had happened at 95% I would have suspected it, but now it was around 15%.

Even if it had transfered I think the .DSK file is still to big to fit the disk so I don't know how to store it since I don't have a harddrive. Maybe to the RAM disk M: or something?






Offline JonB

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Re: A Question about file transfer from PC to PCW
« Reply #1 on: 12:04, 13 August 17 »
The DSK format is a raw disk image. Think of it as a digital copy of the disk itself, rather than copies of the files on the disk. You will not be able to read it on the PCW if transferred as a file. It's meant to be used to backup an entire disk and it can be restored (to physical media) using a program such as CPCDiskXP. You can also view the directory and extract files from a DSK file with that software.


If you have a 3.5" floppy on your PCW (and on your PC), you can recreate a disk from a DSK file and use it directly on the PCW.


If you have the HxC or GoTek floppy emulator on the PCW, you can also transfer the DSK to the emulator's SD card and load it on the PCW directly as if it was a floppy disk.




If you want a hard drive on the PCW, I know a bloke who can help you out.   ;)
« Last Edit: 12:11, 13 August 17 by JonB »

Offline GeoffB17

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Re: A Question about file transfer from PC to PCW
« Reply #2 on: 17:29, 13 August 17 »
Oh Jon, such modesty!


Samuel, there are two issues here.  Firstly, there is the problem of transferring the file.   As Jon says, the disk image may well be slightly bigger than the disk, certainly an image file for A: is bigger that A:.   In your case, you can transfer the image to B:, or even M: would be OK, and that would get you around that problem.   It's no good having the image on A: anyway as you'll need a blank disk in A: to write the image to!   DSKWRITE by definition will fill the complete disk, so you'll have to have the DSKWRITE prog and the .DSK file somewhere else.


Secondly, the more immediate problem is that the file transfer has failed, so you cannot get the file over.   This is more immediate.   Kermit should be fairly robust, I don't know about the other prog, but if the transfer got so far OK, then something has intervened.


I hope the destination disk is OK.   The problem could be a faulty A: disk, but you should transfer to B: or M: anyway.   M: would be faster, and more compatible with the sending machine.


What is the sending machine.   If it's a fast PC, then that may be a problem.   If it's running windows, then this could be a problem, as I'm sure you've noticed, windoze does have a habit of of wandering off to 'do it's own thing' from time to time, and this can well leave any DOS process in the lurch.  Do you have an older DOS machine for this task?


Keep us informed.   Could be something fairly simple.


Best wishes,


Geoff

Offline GeoffB17

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Re: A Question about file transfer from PC to PCW
« Reply #3 on: 18:11, 13 August 17 »
Samuel,


I've just looked up about Tera Term, and I note that:


Firstly, it's a fairly big Windoze system, so it could well give rise to some timing problems trying to maintain a link (clearly it can establish the link in the first place) with a slow machine like the PCW,


Secondly, the program is a 'Terminal Emulator' rather than a 'Communications Program' - as I understand such things, these two terms could be pretty much the same thing, but it could also mean that the full focus of each system could be somewhat different, giving rise to potential incompatibilities.


At least check setup info regarding the two systems, especially anything regarding timing, or buffers.   The kermit end, on the PCW, would need larger buffers to handle the possibility of data coming through faster than the PCW can cope with.


Oh, just done a further check.   Use Google, 'Comms program Kermit protocol', and there appears to be a Windows package for free download of Kermit, which I would suspect may be a MUCH better bet than 'Tera Term'.  Advertised as fully compatible with Kermit.
 
Had you tried that?

Geoff
« Last Edit: 18:47, 13 August 17 by GeoffB17 »

Offline JonB

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Re: A Question about file transfer from PC to PCW
« Reply #4 on: 19:54, 13 August 17 »
TeraTerm Kermit file transfers run fine here. I use TT for all RS232 transfers to many different machines (PCW, P2000C, TRS-80, Superbrain, etc).

For the OP's benefit: Kermit is a communications protocol that uses RS232 to transfer files in small chunks called packets form one machine to another. If a packet fails, it retries a number of times. It does not need any hardware handshake to work, either (although hardware handshaking helps with higher transfer speeds), so you can run it across a three wire null modem connection if you like (GND-GND, Tx->Rx, Rx->Tx).

If you have an issue getting a file across to the PCW it is not likely to be caused by TeraTerm.  Try to reduce the transfer speed (baud rate) first.

Buffer overflows don't tend to happen with Kermit transfers because the buffer only needs to be the size of a single packet (although in practice it is bigger on most machines). When you transfer a file from a PC to a PCW, you can see occasional pauses in the transfer as buffers fill and are written to the PCW's floppy. During this time, Kermit on the PCW instructs the Kermit on the PC to pause, then it signals readiness to receive again once the disk operation completes. However, as I said, if you are running too fast, or the PC and PCW settings do not match, it is likely that transfers will fail. I normally use 9600-8-N-1 to do transfers (that's 9600 baud, 8 bits, No parity, 1 stop bit), although I have had to drop back to 4800 baud on occasion.

(If, on the other hand, you were using PIP to transfer files, I agree with Geoff that data would be lost during disk writes, because the sender would carry on sending while the buffer write was in progress. When I first bootstrapped Kermit onto the TRS-80 Model II, I had to break it into much smaller chunks and transfer piecemeal with PIP. The size of each of these chunks was chosen so as to not be bigger than PIP's buffer. It took ages! Then the file was reassembled on the Model II using a variant of a PIP command which I can't remember off the top of my head.)

Quote
Oh Jon, such modesty!
Not really, just pointing the OP to a useful resource as he mentioned hard disks. Besides, I didn't say the bloke was any good!  ;D

What I do not understand is why the OP seems to want to transfer a DSK image file to his PCW. If he succeeds, how is he going to read its contents? His only option would be to load the image onto a floppy drive emulator like HxC or use CPCDiskXP to extract files from the IMG and transfer them using Kermit (on TeraTerm) - always assuming he hasn't got a 3.5" drive on his PCW and PC.
« Last Edit: 19:59, 13 August 17 by JonB »

Offline GeoffB17

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Re: A Question about file transfer from PC to PCW
« Reply #5 on: 20:45, 13 August 17 »
Thanks for the update, Jon.   As previously mentioned, I've never had much need to mess with SIO, so there are grey areas here.


Just to update regarding your last query, OP has DSKWRITE, so if he can transfer the DSK file to his system (hopefully to B: or M:), then he SHOULD be able to use DSKWRITE to create an A: disk.   However, I've just checked the notes for DSKWRITE, and I note that it can do CPCEMU format ONLY, and will NOT do the 'extended' variants, so there will be problems if he gets a .DSK image in 'extended' format, but we'll sort that if it comes up.


Thanks.


Geoff

Offline zamuel_a

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Re: A Question about file transfer from PC to PCW
« Reply #6 on: 22:35, 13 August 17 »
Everything works now and I was able to create a real disk from a .DSK image! The only problem was that I tried to send the image to a disk that was to small for it. When I changed the drive to M: in Kermit I could transfer here and after that create the real disk!

Offline JonB

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Re: A Question about file transfer from PC to PCW
« Reply #7 on: 10:54, 14 August 17 »
Interesting. Did you create the real disk on the PCW, and if so, what program did you use?


[Edit: It's DSKWRITE.COM - Geoff already said this in post #6..]
« Last Edit: 16:08, 14 August 17 by JonB »