On Sun, 11 Jun 2017, Jay Jaeger wrote:
Yes, I am doing the drawings at 600DPI, including the drawings that
reside inside a couple of the maintenance manuals (but 400DPI for the
text, etc.)
Please do *everything* at 600dpi, disk space and file sizes for such
documents don't matter these days, e
I had the privilege of doing Chuck's oral history for CHM a few years ago.
From: Christine Thacker [mailto:thac...@nhm.org]
Sent: Monday, June 12, 2017 6:58 PM
Subject: Chuck Thacker
Roy, Alan, Butler & Kurt,
I'm sorry to tell you that my father Chuck Thacker passed away in the
early hours
On Mon, Jun 12, 2017 at 3:13 PM, Keven Miller(rtt) via cctalk
wrote:
> 1. IBM 2.10 DOS Technical Reference, Sep 1983
> 2. IBM Hardware Technical Reference, Jan 1983
>
> Hopefully the picture comes through.
No. It did not. Attachments are stripped on this list. No pictures
come through.
-et
In the early 1980's, a company in Toronto, Hazelcom Industries,
produced a music synthesizer based on an LSI-11/23 running
RSX-11M v3.2. The music part of it was written by David McLey,
so the product was called the McLeyvier (pun intended).
Several people in the industry have told me that this
The CHM has posted this on their blog:
I thought you all (especially DEC buffs) would appreciate this:
https://goo.gl/BV6MXH
I have personally reviewed several boxes of the DEC archives - and they
are a terrific asset in understanding both DEC's business successes
and failures, engineering prowes
On 6/13/17 11:22 AM, Alan Frisbie via cctalk wrote:
> 2. DTC 520-1 disk controller and its DTC-11 Q-Bus host adapter.
>
> Our current project is to replace the ST-506 disks with
> the David Gesswein MFM disk emulators. To do this, we
> need to determine the CRC algorithm used by DTC, which w
On 6/13/2017 11:28 AM, Ethan Dicks via cctalk wrote:
On Mon, Jun 12, 2017 at 3:13 PM, Keven Miller(rtt) via cctalk
wrote:
1. IBM 2.10 DOS Technical Reference, Sep 1983
2. IBM Hardware Technical Reference, Jan 1983
Hopefully the picture comes through.
No. It did not. Attachments are stri
On Tue, Jun 13, 2017 at 12:39 AM, Chuck Guzis via cctalk <
cctalk@classiccmp.org> wrote:
> The trimpot on the board says to me that the clock is most likely a
> simple RC affair.
That does seem likely.
>For low bitrates, that's perfectly adequate.
>
A person might think so, but as DEC fou
On Tue, Jun 13, 2017 at 5:26 PM, Eric Smith via cctalk
wrote:
> DEC went through multiple board revisions with changes to the RC oscillator
> in attempt to make it sufficiently reliable. I've heard that they finally
> up and putting a crystal oscillator on the board, but all of mine have the
> RC,
On Tue, Jun 13, 2017 at 5:45 PM, Ethan Dicks via cctalk <
cctalk@classiccmp.org> wrote:
> On Tue, Jun 13, 2017 at 5:26 PM, Eric Smith via cctalk
> wrote:
> > DEC went through multiple board revisions with changes to the RC
> oscillator
> > in attempt to make it sufficiently reliable. I've heard t
On 2017-Jun-13, at 2:26 PM, Eric Smith via cctalk wrote:
> On Tue, Jun 13, 2017 at 12:39 AM, Chuck Guzis via cctalk <
> cctalk@classiccmp.org> wrote:
>
>> The trimpot on the board says to me that the clock is most likely a
>> simple RC affair.
>
> That does seem likely.
There's a 7493 (4-bit cou
On 06/13/2017 02:26 PM, Eric Smith wrote:
> On Tue, Jun 13, 2017 at 12:39 AM, Chuck Guzis via cctalk
> A person might think so, but as DEC found out with the PDP-11/05
> console serial port, it's really not. The percentage tolerance of
> async serial is not any higher at low bit rates than at high
On Tue, Jun 13, 2017 at 5:53 PM, Chuck Guzis via cctalk <
cctalk@classiccmp.org> wrote:
> The TR1602 UART, like its cousin, the AY-3-1013 used in the TVT,
> tolerates a pretty wide range of bit rate distortion. The app note
> gives a figure of something like 49%. And, since it's async, the game
> On Jun 13, 2017, at 8:29 PM, Eric Smith via cctalk
> wrote:
>
> ...
> * I refer to a "normal UART" as one that oversamples the receive data
> signal (typically at 16x the bit rate) to find the leading edge of the
> start bit, delays 1/2 bit time, then samples the start bit and subsequent
> da
On 06/13/2017 05:29 PM, Eric Smith wrote:
> It's mathematically impossible for a normal UART [*] to handle 49%
> timing error. The cumulative timebase error by the end of a
> character can't be more than one bit time, or the wrong bit will get
> sampled, resulting in incorrect data, or, (if that
On Tue, Jun 13, 2017 at 6:59 PM, Chuck Guzis via cctalk <
cctalk@classiccmp.org> wrote:
> Well, I didn't say "timing error", I did say "timing distortion", which
> is not quite the same thing. My reference was the "TR1602/TR1863/TR1865
> MOS/LSI Application Notes Asynchronous Receiver Transmitter"
On 06/13/2017 06:27 PM, Eric Smith wrote:
> They sold it, then spent a bunch of money on Field Service trips to make
> it work for customers. It cost them enough to justify multiple
> redesigns, including (finally) switching to a crystal.
The TRS-80 board? Do you have any documentation on Field
On 06/13/2017 07:59 PM, Chuck Guzis via cctalk wrote:
Well, I didn't say "timing error", I did say "timing
distortion", which is not quite the same thing. My
reference was the "TR1602/TR1863/TR1865 MOS/LSI
Application Notes Asynchronous Receiver Transmitter",
which can be found in the WD 1984
Hi All
Whilst I do have a reasonable stock of panels.
The prospect of getting more made is doubtful as my silk screen people
are more interested in T-shirts.
As demand is low I might level the quantities out via ebay.
Rod Smallwood
--
There is no wrong or right
Nor black and whit
All have been claimed.
Keven Miller
In case you hadn't heard, the DEC archives at CHM are available and here's
the PDF:
http://archive.computerhistory.org/resources/access/text/finding-aids/102733963-DEC/102733963-DEC.pdf
Now, I wonder if it has Firefly docs...
I got quite a few interesting 1970's area chips in a recent component haul
in Palo Alto, CA (which had originally been advertised here). A whole TTL
series complement of course, but some old DTL stuff too and some early Intel
bipolar memories and Intel 8080 support chips. However there is a chip th
It's actually a legit measurement, but it's basically how much total jitter
+ bit-proportioned rate error the rx signal can have as a percentage of bit
time, and doesn't matter nearly as much when receiving from all-electronic
transmitters, vs mechanical such as TTY.
I'm sure it made the marketing
I'll also grant that there's a big difference between driving one or two
meters of cable and one or two hundred meters with TIS232 levels.
--Chuck
> > I may be looking into that myself by this time next week. There's a
> > good chance there might be an 11/05 coming my way.
> >
> > -ethan
> >
>
> The console is great for teletype, but otherwise use a M7800 or equiv.
> b
>
I have had no problems with the RC controlled baud rate generator on t
Hi
We are ok for now but for future and as yet not designed panels I
can still draw them. (I'm old but not that old)
However with modern technology there has to be a multi-pass printer that
can print on perspex (plexiglass) and closely simulate silk screening
My goal is to be able to ke
Just a bit too far for me. But there are a few questions I'd like answering.
For example there was the time I was working for the Terminals Product
Line and was over in the US
I walked into the building one morning at Marlboro to find that the
Product Line Manager (Bill Chalmers) and a lot of
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