File transfer protocols

[Xebec]

What are or were some of the more exotic file transfer protocols for the 8bit?

 

I remember in later years running PCBoard and being excited to try new ones like ymodem-g, Puma, Bimodem, etc.

 

But on the 8bit I'm only remembering xmodem, xmodem crc, and Kermit (mainly for CompuServe?). I'm sure there was a ymodem. Anything unusual or specific to the a8 out at the time ?

[Rybags]

ZModem was better again than Y and X. They're just file transfer protocols and there's little importance insofar as what hardware each peer is running, doesn't matter really if it's a PDP-11 or ZX Spectrum at the other end.

 

Improvements were made along the way in areas like error recovery/correction, more efficient packet sizes, sliding window for compression etc.

 

I remember with some terminal dialin situations being presented with a bunch of options and ZModem was always the preferable way of doing things.

Not sure if there's restrictions for what circumstances a protocol can or can't be used. I would guess you probably have to be at least in an 8 bit mode, unsure it bitrate matters.

[Mr Robot]

Zmodem came out in 86, pretty late in the A8 lifespan, I remember using it on Amigas.

 

Kermit and Xmodem were all I used on A8

[Level42]

Yeah I have my doubts about Zmodem on A8' too....but I may very well be wrong........on the ST it was not available until a bit later....I remember first using ymodem.....when zmodem arrived I never used anything else. Especially because it supports interrupts in file transfers.....which could happen in the age of dial-up connections.....

[+Nezgar]

Y-Modem Batch was the most compatible option available for A8 that provided 1KB transfer blocks, automatic filename and file size, and of course, multiple files back to back. 1KB was much better than X-Modem's 128bytes on faster modems due to additional latency. File name & batch capability avoided need to type it in for each file, and file size resolved the issue with up to 127 extra bytes at the end of downloaded X-modem files.

 

The Y-Modem batch variation that I only saw on the 8-Bits, was F-Modem - transferred files in 4KB blocks. BobTerm supports this, as well as BBS Express! Pro. Pro even used this protocol by default for networking calls between other BBS's. This was also a life-saver when I used a service to dial from Vancouver to Toronto over a Datapac service to avoid long distance, which had huge latency, over a second or 2 i remember... F-Modem was best for this as there was less pauses to acknowledge each packet. I Don't remember F-Modem being an option on any ST terminal programs.

 

I do recall very late in the game someone did actually write a Z-Modem receiver for the 8-Bit - Every time the buffer would fill up, and have to write to disk, the data would obviously keep streaming in while this was happenning, so it would just transmit a reposition to the sender each time it finihsed writing the buffer... It worked, but some senders might see more than 10 of these as a problem and abort.

[+Nezgar]

Yeah I have my doubts about Zmodem on A8' too....but I may very well be wrong........

 

I'll have to dig through my old hard drive partitions to see if my vague memory is correct!!

[_The Doctor__]

remember certain terminal programs added errors to their transfers or added garbage at the end of files... Express Cart 1.12 had such issues as did some revision of Bobterm etc. I don't recall the rev but I am sure someone here can dig up the know terminal transfer programs and the related bugs and what the good revision of the program without the errors would be or at least a patcher to fix said issue..

Edited October 27, 2017 by _The Doctor__

[zzip]

What are or were some of the more exotic file transfer protocols for the 8bit?

 

I remember in later years running PCBoard and being excited to try new ones like ymodem-g, Puma, Bimodem, etc.

 

But on the 8bit I'm only remembering xmodem, xmodem crc, and Kermit (mainly for CompuServe?). I'm sure there was a ymodem. Anything unusual or specific to the a8 out at the time ?

 

I always liked Zmodem best, it built off xmodem and ymodem and it had quality of life features like automatically starting downloads on your end

 

EDIT: I'm pretty sure I had zmodem on 8-bit and ST

Edited October 27, 2017 by zzip

[_The Doctor__]

you did...

[+Stephen]

I believe Ice-T supports Z-modem. Back when I was regularly BBSing (87-90) I did not know of it. Pretty sure the most advanced I used was Y-modem. I loved the batch features, only useful when I went from 300 baud to 1200 baud.

 

Amazing thinking back to the old days. I just got a free upgrade from my ISP. Went from 70Mbit down to 100Mbit down, 12 up!

[+David_P]

Here's a scanned copy of my hardcopy of the documentation for Atari Zmodem. Apparently, I needed a new printer ribbon back in the day...

 

 

EDIT: Forgot to click "Attach this File" Oops!

Atari ZModem.pdf

[Mr Robot]

V1.0 1994!

 

Well past the time I was bbs'ing on the A8. It's nice to see that it was available at the end though!