Thanks Dwight. I call it "digital archaeology". Doing a little more work on it today, trying to see what responses it might expect from the remote system. I did find specific text strings that have "CPM" in it, so my theory about the origination is probably right. I'm hoping to use some "six degrees of Kevin Bacon" here...maybe someone knows someone who knows. I may post the edited listing file at some point. Rich ?On 9/27/20, 1:35 PM, "cctalk on behalf of dwight via cctalk" <cctalk-bounces at classiccmp.org on behalf of cctalk at classiccmp.org> wrote: This is great work, Rich. It is like looking at dinosaur bones and trying to figure what it was eating. Dwight ________________________________ From: cctalk <cctalk-bounces at classiccmp.org> on behalf of Richard Cini via cctalk <cctalk at classiccmp.org> Sent: Sunday, September 27, 2020 7:07 AM To: Discussion: On-Topic Posts Only <cctech at classiccmp.org> Subject: SCP/Microsoft 20HAL uploader All ? I?ve done a quite a bit of work with my Seattle Gazelle, and I just did some work on 86DOS.SYS (not released in source form, as far as I know) and its comparison to PC DOS 1.0 (at the code level, a very high correlation as you can imagine). Partially related to that is a program called ?20HAL? which was a code uploader Microsoft used in the late stages to get code from Microsoft in Bellevue to IBM in Boca Raton, FL. I did a little write-up on it here (http://www.classiccmp.org/cini/hal.htm) There are some holes in the analysis ? I think it?s pretty close, though -- but I?d really like to get some more details on it. Unfortunately, it?s 40-year-old code at this point, and how many people remember how they used a file transfer utility that long ago? Anyway, enjoy the read. If anyone sees any corrections that need to be made, let me know. Thanks! Rich -- Rich Cini http://www.classiccmp.org/cini http://www.classiccmp.org/altair32

Excellent! That?s a great piece of info. Not sure why a TOPS-10 command would be embedded in a program like this. The notion of filtering/delay itself makes sense but that command would make sense only if IBM had a DECSYSYEM too, no? http://www.classiccmp.org/cini Long Island S100 User?s Group Get Outlook<https://aka.ms/qtex0l> for iOS ________________________________ From: cctalk <cctalk-bounces at classiccmp.org> on behalf of Dennis Boone via cctalk <cctalk at classiccmp.org> Sent: Sunday, September 27, 2020 8:22:00 PM To: cctalk at classiccmp.org <cctalk at classiccmp.org> Subject: Re: SCP/Microsoft 20HAL uploader The TOPS-10 manual says that: (SET) TTY FILL n sets delay characteristics for the line to class `n`. There's a table of the number of filler characters sent after each of a number of different control characters. Class 3 uses the most fillters. The filler characters used are CR after a CR, and DEL after all the others. It could make sense to do this during a file transfer, depending on the assorted endpoints, etc. De

That part's a puzzler. Perhaps the link was from the PC to the MS DEC-10 and thence out to IBM? De

On Sun, Sep 27, 2020, 8:12 PM Richard Cini via cctalk <cctalk at classiccmp.org> wrote: It's how printers were connected... Warner Maybe the development machine was connected to a pass through serial port