cctalk Digest, Vol 88, Issue 30
Bob Smith
bobsmithofd at gmail.com
Sun Jan 30 15:46:00 CST 2022
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>
>
> > 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_16-line_Multiplexer_Users_Manual_Sep76.pdf
>
> 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:
> >
> >> 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_16-line_Multiplexer_Users_Manual_Sep76.pdf
> >
> > 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: 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:
> >
> >
> >> 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_16-line_Multiplexer_Users_Manual_Sep76.pdf
> >>
> >> 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
> >
>
> --
> 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:
> >
> > 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_16-line_Multiplexer_Users_Manual_Sep76.pdf
> > >>
> > >> 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
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