Path: utzoo!utdoe!generic!pnet91!sysadmin
From: sysadmin@pnet91.cts.com (Matthew Montano)
Newsgroups: comp.sys.apple2
Subject: Re: GBBS/ProTERM Ymodem info, anyone?
Message-ID: <323@generic.UUCP>
Date: 29 Dec 90 01:33:23 GMT
Sender: root@generic.UUCP
Organization: People-Net [pnet91], Etobicoke, ON
Lines: 33

marekp@pnet91.cts.com (Marek Pawlowski) writes:
>vw3@cunixf.cc.columbia.edu (Vernon Williams) writes:
>>Some software packages call XMODEM 1K "YMODEM" though this is not correct.
>>Someone was just talking about this on a local BBS just the other day.
>Calling it Ymodem may not be correct, however, they are essentially identical.
>
>Ymodem is Xmodem CRC (16 bit checksum) with 1k packets.
>
>Only major difference is that Ymodem tends to be the one with Batching
>ability.
>

Nope.. Ymodem is meerly Xmodem with a block 0 containing file name, type,
creation date information. Because of this nature it is sometimes called
Ymodem-Batch.. but Ymodem to those who hack with this stuff should mean the
same thing. Xmodem-1k is Xmodem with 1k packets. Xmodem exists in Checksum and
CRC error correction method.. I don't know of an implementation of Xmodem-1k
or Ymodem that supports Checksum error correction.

A good reference on this is "The C Programmers Guide to Serial Communications"
by Campbell and published by Howard Sams and Company.

(Gee, correcting my co-sysop.. what form!)
>
>/* Marek Pawlowski, marekp@{generic|pnet91|contact|bkj386|torag|aunix}.uucp */
>/* President, Intelligent Twist Software, 250 Harding Blvd, PO BOX 32017    */
>/* Richmond Hill, Ontario, L4C 9M7, CANADA.  An ideal route is as follows:  */
>/* { Ph: (416) 884-4501 4-8pm EDT } generic!pnet91!marekp@zoo.toronto.edu   */

---
Email: sysadmin@pnet91.cts.com (most mailers won't barf on that..)
My comments aren't even worth a disclaimer...
pnet91 - 416-237-{1204|0308}. 2400bps only. 1200bps if you do hard breaks.