SCP/Microsoft 20HAL uploader

Richard Cini rich.cini at
Sun Sep 27 21:12:39 CDT 2020

Great point. Does a VT100 have a pass-through serial port? Maybe the development machine was connected to a pass through serial port on a terminal and then sent command to the DEC-20 to send the files. So there would have been some sort of connection from the DEC-20 to IBM. Leased line? Packet switched?

A great puzzle.
Long Island S100 User’s Group

Get Outlook<> for iOS

From: cctalk <cctalk-bounces at> on behalf of Dennis Boone via cctalk <cctalk at>
Sent: Sunday, September 27, 2020 10:03:23 PM
To: cctalk at <cctalk at>
Subject: Re: SCP/Microsoft 20HAL uploader

> 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?

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


More information about the cctech mailing list