30 Jan
2022
30 Jan
'22
1:46 p.m.
IIRC, John Mac was the designer for the DHQ/DHV. If my memory is
correct, after DH was done, John had the idea of a mix and match
synchronous/Async mux and came up with those designs. I dont remember
who was on his team. COMMS 11 group had led (farmed out) the designs
of the Sync version of a UART called USynRT in some parlance SIg 2652
and SMC 5027 IIFC. I ran the Signetics contract tech side. A fresh MIT
PhD was the Sig POC, and there are more stories about that. I cant
recall his name at this juncture.
bob
On Sun, Jan 30, 2022 at 1:00 PM <cctalk-request at classiccmp.org> wrote:
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Today's Topics:
1. Re: What was a Terminal Concentration Device in DEC's
products? (Noel Chiappa)
2. Re: What was a Terminal Concentration Device in DEC's
products? (Paul Koning)
3. Re: What was a Terminal Concentration Device in DEC's
products? (Chris Zach)
4. Re: What was a Terminal Concentration Device in DEC's
products? (Glen Slick)
5. Re: What was a Terminal Concentration Device in DEC's
products? (Noel Chiappa)
----------------------------------------------------------------------
Message: 1
Date: Sat, 29 Jan 2022 15:58:53 -0500 (EST)
From: jnc at mercury.lcs.mit.edu (Noel Chiappa)
To: cctalk at classiccmp.org
Cc: jnc at mercury.lcs.mit.edu
Subject: Re: What was a Terminal Concentration Device in DEC's
products?
Message-ID: <20220129205853.15EEA18C07B at mercury.lcs.mit.edu>
--
Sent from my Android device with K-9 Mail. Please excuse my brevity.
------------------------------
Message: 4
Date: Sat, 29 Jan 2022 16:47:27 -0800
From: Glen Slick <glen.slick at gmail.com>
To: "General Discussion: On-Topic and Off-Topic Posts"
<cctalk at classiccmp.org>
Subject: Re: What was a Terminal Concentration Device in DEC's
products?
Message-ID:
<CAM2UOwL2hi2Crm7ovphGd+UZFPePV+vUzoduan7a2a5Xo+eimw at mail.gmail.com>
Content-Type: text/plain; charset="UTF-8"
http://www.bitsavers.org/pdf/dec/qbus/EK-DHQ11-UG-002.pdf
DHQ11 User Guide, EK-DHQ11-UG.002
The main application of the M3107 DHQ11 is for interactive terminal
handling; it can also be used for data concentration and real-time
processing. It has two programming modes, DHV11 and DHU11. The
register sets in these modes are compatible with those of the DHV11
and DHU11 respectively. The preferred mode of operation is DHU11 mode.
The main features of the DHQ11 are:
? For transmission: DMA transfers; or for each line, program transfers
to a 1 character transmit buffer in DHV11 mode, or to a 64-character
transmit FIFO in DHU11 mode
? For receive: a 256-entry FIFO buffer for received characters,
dataset status changes, and diagnostic information
The M3118 CXA16 and the M3119 CXA08 have the same programming
interface as the M3107 DHQ11
The M3108 DSV11 can do DMA transfers in both directions, although it
is a synchronous interface, not asynchronous.
http://www.bitsavers.org/pdf/dec/qbus/EK-DSV11-TM-001_Jan87.pdf
DSV11 Technical Manual, EK-DSV11-TM-001
Functional Description (Section 1.5). The DSV11 supports a range of
synchronous protocols on the serial interface, and transfers data to
and from the host by DMA transfer. This section describes the way in
which the DSV11 handles data.
On Sat, Jan 29, 2022 at 3:49 PM Chris Zach via cctalk
<cctalk at classiccmp.org> wrote:
From: Paul Koning
DH-11 is unusual in that it has DMA in both
directions
McNamara's DH11? (I don't know of another DECdevice of that name.) Per:
http://www.bitsavers.org/pdf/dec/unibus/EK-ODH11-OP-002_DH11_Asynchronous_1…
it's DMA on output only; the input side has a FIFO that has to be emptied by the
CPU.
Noel
PS: I am familiar with the term 'terminal concentrator' from the networking
world, but as a generic term, not the name of a particular product. (Although
Cisco's first boxes may have included a terminal concentrator, so named.)
Noel
------------------------------
Message: 2
Date: Sat, 29 Jan 2022 17:12:41 -0500
From: Paul Koning <paulkoning at comcast.net>
To: Noel Chiappa <jnc at mercury.lcs.mit.edu>, "cctalk at
classiccmp.org"
<cctalk at classiccmp.org>
Subject: Re: What was a Terminal Concentration Device in DEC's
products?
Message-ID: <684F1FCF-A6E6-4F3C-AC39-ADA1504FC9E1 at comcast.net>
Content-Type: text/plain; charset=us-ascii
On Jan 29, 2022, at 3:58 PM, Noel Chiappa via
cctalk <cctalk at classiccmp.org> wrote:
Oh. That's amazing, all these years I thought it had DMA both ways. Clearly not. I
wonder how I got that misunderstanding.
paul
------------------------------
Message: 3
Date: Sat, 29 Jan 2022 18:49:06 -0500
From: Chris Zach <cz at alembic.crystel.com>
To: Paul Koning <paulkoning at comcast.net>, "General Discussion:
On-Topic and Off-Topic Posts" <cctalk at classiccmp.org>, Paul Koning
via
cctalk <cctalk at classiccmp.org>, Noel Chiappa
<jnc at mercury.lcs.mit.edu>, "cctalk at classiccmp.org"
<cctalk at classiccmp.org>
Subject: Re: What was a Terminal Concentration Device in DEC's
products?
Message-ID: <24F062E4-8B26-4EB3-A573-B47C69A53B67 at alembic.crystel.com>
Content-Type: text/plain; charset=utf-8
Maybe that is the dhv11. Or the dv11 I'll look it up tomorrow
On January 29, 2022 5:12:41 PM EST, Paul Koning via cctalk <cctalk at
classiccmp.org> wrote:
From: Paul Koning
DH-11 is unusual in that it has DMA in both
directions
McNamara's DH11? (I don't know of another DECdevice of that name.) Per:
http://www.bitsavers.org/pdf/dec/unibus/EK-ODH11-OP-002_DH11_Asynchronous_1…
it's DMA on output only; the input side has a FIFO that has to be emptied by the CPU.
On Jan 29, 2022, at 3:58 PM, Noel Chiappa via
cctalk <cctalk at classiccmp.org> wrote:
Oh. That's amazing, all these years I thought it had DMA both ways. Clearly not. I
wonder how I got that misunderstanding.
paul
From: Paul Koning
DH-11 is unusual in that it has DMA in both
directions
McNamara's DH11? (I don't know of another DECdevice of that name.) Per:
http://www.bitsavers.org/pdf/dec/unibus/EK-ODH11-OP-002_DH11_Asynchronous_1…
it's DMA on output only; the input side has a FIFO that has to be emptied by the CPU.
Maybe that is the dhv11. Or the dv11 I'll look it up tomorrow
On January 29, 2022 5:12:41 PM EST, Paul Koning via cctalk <cctalk at
classiccmp.org> wrote:
>
>
>> On Jan 29, 2022, at 3:58 PM, Noel Chiappa via cctalk <cctalk at
classiccmp.org> wrote:
>>
>>> From: Paul Koning
>>
>>> DH-11 is unusual in that it has DMA in both directions
>>
>> McNamara's DH11? (I don't know of another DECdevice of that name.) Per:
>>
>>
http://www.bitsavers.org/pdf/dec/unibus/EK-ODH11-OP-002_DH11_Asynchronous_1…
>>
>> it's DMA on output only; the input side has a FIFO that has to be emptied by
the CPU.
>
>Oh. That's amazing, all these years I thought it had DMA both ways. Clearly
not. I wonder how I got that misunderstanding.
>
> paul
------------------------------
Message: 5
Date: Sun, 30 Jan 2022 09:26:46 -0500 (EST)
From: jnc at mercury.lcs.mit.edu (Noel Chiappa)
To: cctalk at classiccmp.org
Cc: jnc at mercury.lcs.mit.edu
Subject: Re: What was a Terminal Concentration Device in DEC's
products?
Message-ID: <20220130142646.5614818C074 at mercury.lcs.mit.edu>
From: Chris Zach
Maybe that is the dhv11.
The DH11, DHV11 and DHU11 are all very similar, although not 100.00% program compatible.
(The DHQ11 can be set to exactly emulate either the DHV11 or DHU11.) So, all provide
DMA output, but not DMA input.
Differences with the DH11 include two full word registers for DMA address,
hardware ^S/^Q support, built-in diagnostics, etc. The DHV11 and DHU11 differ
in hardware echo, output FIFO, a fix for the infamous DH11 input silo level
bug, etc.
Noel
End of cctalk Digest, Vol 88, Issue 30
**************************************