We used to do asynchronous ddcmp using a terminal line on a micro VAX 2 having loaded NODRIVER. Keith On 10 Dec 2021, at 20:29, Thomas DeBellis <tommytimesharing at gmail.com> wrote: ? I know VMS at least did some kind of line. Columbia's chemistry department got a VAX before the campus Ethernet existed, so that wouldn't have been an option. However, I can't remember whether it was a synchronous or asynchronous connection; only that the 'wire' went into one of our DN20's (I think CU20B). I think the 'wire' had modems on both sides, but I can't remember what those were, either. On 12/10/21 3:24 PM, Mark Pizzolato - Info Comm wrote: On Friday, December 10, 2021 at 12:19 PM, Paul Koning wrote: On Dec 10, 2021, at 2:32 PM, cyb 2600 <cyb2600 at gmail.com><mailto:cyb2600 at gmail.com> wrote: Hello, A little while ago I purchased an HP BL860c server blade. It has an Itanium 2 CPU and I was able to install OpenVMS 8.4 on it. However I do NOT have a HP Bladesystem chassis to put the blade in, meaning I can only connect to it via the SUV console cable which provides usb, serial, and VGA. There's no way to get ethernet out of the thing without plugging it into a rather gigantic Bladesystem chassis that I don't have. If it was an x64 based blade running windows I could just use a USB->Ethernet adapter but of course those things don't have OpenVMS drivers. Given ethernet's not an option, would there be any way to tunnel DECNET over the serial port? It seems like that was possible on VAXen and maybe even Alphas but I've no mention of doing it on an Itanium. Or if anybody else has any ideas of how I could network this thing I would appreciate it. I don't know that VMS ever did it, but a number of DECnet systems support DDCMP over async lines (terminal serial ports). That's part of the standard. VAX/VMS certainly did async DDCMP. I've no idea if that functionality got migrated to Alpha and Itanium. I'd suggest you try following the VMS example. If you can get the configuration steps to work (suggesting Itanium support) then this should work with a serial line going into a simh VAX. Good Luck, - Mark

Thanks - this old thread on comp.os.vms says DDCMP is VAX only. If it didn't make it to Alpha then I doubt it made it to Itanium but it can't hurt to try. https://groups.google.com/g/comp.os.vms/c/TcbXQkCFd8s The OpenVMS 8.4 manual implies SLIP would work, though. Could I do something with that? "SLIP includes CSLIP (compressed SLIP). You can use any standard OpenVMS terminal device as a PPP or SLIP line. (PPP is available for OpenVMS Alpha systems only.)" On Fri, Dec 10, 2021 at 3:36 PM Paul Koning <paulkoning at comcast.net> wrote:

The only system I know well is RSTS/E. The only sync comm link it supported were DMC11 and its offshoots DMR11 (same features, modernized design), DMP11 (added multipoint) and DMV11 (like DMP except Qbus). All except DMV could run up to 1 Mb/s and in fact that speed was achievable. DMV ran at a max of 56 kbps, I'm not sure why. That board has a very different design, much smaller. The DMC/DMR/DMP are all variations on the KMC11 microcontroller, with a directly-connected line card. There actually were two line cards: one "integral modem", coax connected for up to 3 miles or so distance at speeds in the 56k to 1M range. The other was a modem card (RS232, RS422, V.35) for up to 56 kbps if the modem could go that fast. (Perhaps more but I don't know of modems that would do so). The KMC you mentioned was a programmable engine which could do DMA and Unibus transactions, so it was paired with sync or async comm devices to offload DDCMP processing. The idea is that the host would talk to the KMC with a packet API, and the KMC would then talk on its behalf to the actual UART or USRT with byte-oriented transactions to do the real communication. You'd still have a whole lot of bus activity but no character-level interrupts to the host. I don't know what speeds were achievable with KMC-DUP or KMC-DZ, the two pairs I know of. Part of the question is what the most is those character devices could do. Someone else might have those details. RSTS never supported KMC for DECnet, though it did for RJ2780 I think. DUP alone can also be used, in that case you'd be looking at DDCMP in software and a driver directly controlling a character device. That wasn't in RSTS either, but as I mentioned I did implement driver-level DDCMP for serial ports. That normally meant UARTs, though the comm port on the Pro can do either sync or async and my driver for it supports both modes. Given the slow CPU and the insanely ugly interrupt architecture of the Pro series, 9600 baud is problematic and anything faster is entirely out of the question. 4800 works fine, and if you have the ability to use odd speeds it's possible to get nice reliable operation at, say, 8000 bps or so. The reason it's problematic to go fast is that on the Pro you're competing with other high rate interrupts from devices like the console display frame buffer. paul

On 12/10/21 7:08 PM, Thomas DeBellis wrote: That's the KMC-11, and it does indeed have a processor on it. It can do all sorts of protocol processing, very flexibly. It's a weird connection to have, but I was romantically involved with the daughter of the designer of that board for a while, and have been friends with him just about forever. He gave most of his personal DEC hardware to me many years ago, and it's at LSSM now. He's based in Maryland. He's still very much around and still loves DEC stuff; I should talk him into joining us here. -Dave -- Dave McGuire, AK4HZ New Kensington, PA