[HECnet] DDCMP over asynchronous emulated lines on simh 4.0

[Johnny Billquist]

On 2013-05-02 21:20, Clem Cole wrote:

On Wed, May 1, 2013 at 10:32 PM, Johnny Billquist <bqt at softjar.se
<mailto:bqt at softjar.se>> wrote:

      Are you sure about Able? I can't remember seeing any such thing from
      them.


Quite sure - the "other KO" designed it - Ken O'h*   (I don't remember
how to spell is last name).   Ken O'h formed Able after Olsen shut him
down with the CalData machine (an 11/45 clone).

The Able 16 port serial product was called the DHDM.   I wish I still had
one.   I do still have the doc set for them in the basement, along with
his original "Enable" card he built for us UNIX guys - which was a slick
take on a cache and bus repeater. +

Ok. I have not seen or used an Able DH-11 clone. I know they did lots of other stuff, like the Qniverter. Trying to remember who did the memory upgrade for the 11/34, but I don't think that was Able...

The DHDM could definitely do speeds of 19.2K but I think they could do
38.4K and may be higher, I forget - have to look at the prints ;-)     I
put the code into BSD support the higher speeds, base AT&T used the EXT
A/B stuff.     I'm pretty sure the original DEC DH maxed at 9600.

Yes, the DEC DH-11 maxed out at 9600.

As for your other comment about "enough for common use" WRT the modem
control lines - actually that was not true for the UNIX community.     DZ
was short pinned++ one had enough to sort of support >>dial-in<< (i.e.
off-hook/CD detection   but because if used wanted to run uucp, modems
needed to control an autodialers and thus needed to support the whole
magilla.     Remember UNIX comes from the TPC (The Phone Company) - so
base UNIX had all the support for AT&T communications equipment.

The comments about "enough for common use" was about the Emulex DH-11 clone... As far as I remember, the DEC DH-11 in combination with a DM-11 provided more control over modem signalling than the Emulex clone, but the Emulex clone implemented enough for the common use case. I don't offhand remember what parts of the DM-11 that the Emulex didn't implement, but I don't think it was any parts you normally would have cared about.

But yeah, the DZ-11 is also very restricted (actually more restricted) when it comes to modem signalling. (But like I said, I totally do not like the DZ-11.)

	Johnny

-- 
Johnny Billquist                                   || "I'm on a bus
                                                                  ||   on a psychedelic trip
email: bqt at softjar.se                         ||   Reading murder books
pdp is alive!                                         ||   tryin' to stay hip" - B. Idol