-------- Original message --------
From: Josh Dersch <derschjo at gmail.com>
Date: 2017-01-02 7:37 PM (GMT-08:00)
To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org>
Subject: Re: National Semiconductor IMP mini
On 1/2/17 7:22 PM, jim stephens wrote:
> This system looks pretty interesting, though pricey. I'm thinking it
> is going to be a development machine as all the switches and display
> would not probably have been on a production machine.
>
> I don't think National made many minicomputer format machines, in
> their history, someone correct me.? That might make this pretty rare
> on that front as well.
>
> thanks
> Jim
>
> Beautiful-1974-NATIONAL-SEMICONDUCTOR-COMPUTER-model-imp-16p/
> http://www.ebay.com/itm/252700755919
>
Yeah, it's pretty cool but I don't think the seller has reasonable
expectations for actually selling it -- the auction started (I believe)
at $1500 (which may have been a reasonable price), then the seller
raised it to $2500, now it's at $3500 (which is fairly outrageous, in my
>opinion).? I'm not sure what his strategy is.
>Bitsavers has manuals (of course...)
>- Josh
I think he figured toggle switches and lights = $$$$. ?He might be correct, given the obscene money I've seen laid out just for a PDP 8/e faceplate. You never know a) what will motivate a collector and b) when just the right collector for a given item will show up. ?Every day I thank my lucky stars they didn't, for whatever reason, show up for my Mark-8 boards.
Bitsavers
http://bitsavers.trailing-edge.com/pdf/national/imp/4200021C_IMP16C_App_Jan…
is same manual..
the 16 P is the machine in ebay. yea a beauty.
Ed#
In a message dated 1/2/2017 9:28:59 P.M. US Mountain Standard Time,
COURYHOUSE at aol.com writes:
SMECC's book is on 16 c
talks about adding front panel and display etc... 16 sw and 16 led book
dated jan 74
16c seems to designate the card maybe 16 b is inclusive of PS an add
on panel and case..
also have a 8C book too.
ED# _www.smecc.org_ (http://www.smecc.org/)
Odd I was just going though a crate 3 hours ago... what are the odds
In a message dated 1/2/2017 9:15:05 P.M. US Mountain Standard Time,
couryhouse at aol.com writes:
I have manual.
Sent from AOL Mobile Mail
____________________________________
On Monday, January 2, 2017 Josh Dersch <derschjo at gmail.com> wrote:
On 1/2/17 7:58 PM, Brad H wrote:
>
> -------- Original message --------
> From: Josh Dersch <derschjo at gmail.com>
> Date: 2017-01-02 7:37 PM (GMT-08:00)
> To: "General Discussion: On-Topic and Off-Topic Posts"
<cctalk at classiccmp.org>
> Subject: Re: National Semiconductor IMP mini
>
>
> On 1/2/17 7:22 PM, jim stephens wrote:
>> This system looks pretty interesting, though pricey. I'm thinking it
>> is going to be a development machine as all the switches and display
>> would not probably have been on a production machine.
>>
>> I don't think National made many minicomputer format machines, in
>> their history, someone correct me. That might make this pretty rare
>> on that front as well.
>>
>> thanks
>> Jim
>>
>> Beautiful-1974-NATIONAL-SEMICONDUCTOR-COMPUTER-model-imp-16p/
>> http://www.ebay.com/itm/252700755919
>>
> Yeah, it's pretty cool but I don't think the seller has reasonable
> expectations for actually selling it -- the auction started (I believe)
> at $1500 (which may have been a reasonable price), then the seller
> raised it to $2500, now it's at $3500 (which is fairly outrageous, in my
>> opinion). I'm not sure what his strategy is.
>> Bitsavers has manuals (of course...)
>> - Josh
> I think he figured toggle switches and lights = $$$$. He might be
correct, given the obscene money I've seen laid out just for a PDP 8/e faceplate.
You never know a) what will motivate a collector and b) when just the
right collector for a given item will show up. Every day I thank my lucky stars
they didn't, for whatever reason, show up for my Mark-8 boards.
With the "No shipping cash on pickup" proviso the seller provides, I
feel fairly certain no one's biting. But I've been surprised before...
- Josh
SMECC's book is on 16 c
talks about adding front panel and display etc... 16 sw and 16 led book
dated jan 74
16c seems to designate the card maybe 16 b is inclusive of PS an add
on panel and case..
also have a 8C book too.
ED# _www.smecc.org_ (http://www.smecc.org)
Odd I was just going though a crate 3 hours ago... what are the odds
In a message dated 1/2/2017 9:15:05 P.M. US Mountain Standard Time,
couryhouse at aol.com writes:
I have manual.
Sent from AOL Mobile Mail
____________________________________
On Monday, January 2, 2017 Josh Dersch <derschjo at gmail.com> wrote:
On 1/2/17 7:58 PM, Brad H wrote:
>
> -------- Original message --------
> From: Josh Dersch <derschjo at gmail.com>
> Date: 2017-01-02 7:37 PM (GMT-08:00)
> To: "General Discussion: On-Topic and Off-Topic Posts"
<cctalk at classiccmp.org>
> Subject: Re: National Semiconductor IMP mini
>
>
> On 1/2/17 7:22 PM, jim stephens wrote:
>> This system looks pretty interesting, though pricey. I'm thinking it
>> is going to be a development machine as all the switches and display
>> would not probably have been on a production machine.
>>
>> I don't think National made many minicomputer format machines, in
>> their history, someone correct me. That might make this pretty rare
>> on that front as well.
>>
>> thanks
>> Jim
>>
>> Beautiful-1974-NATIONAL-SEMICONDUCTOR-COMPUTER-model-imp-16p/
>> http://www.ebay.com/itm/252700755919
>>
> Yeah, it's pretty cool but I don't think the seller has reasonable
> expectations for actually selling it -- the auction started (I believe)
> at $1500 (which may have been a reasonable price), then the seller
> raised it to $2500, now it's at $3500 (which is fairly outrageous, in my
>> opinion). I'm not sure what his strategy is.
>> Bitsavers has manuals (of course...)
>> - Josh
> I think he figured toggle switches and lights = $$$$. He might be
correct, given the obscene money I've seen laid out just for a PDP 8/e faceplate.
You never know a) what will motivate a collector and b) when just the
right collector for a given item will show up. Every day I thank my lucky stars
they didn't, for whatever reason, show up for my Mark-8 boards.
With the "No shipping cash on pickup" proviso the seller provides, I
feel fairly certain no one's biting. But I've been surprised before...
- Josh
This system looks pretty interesting, though pricey. I'm thinking it is
going to be a development machine as all the switches and display would
not probably have been on a production machine.
I don't think National made many minicomputer format machines, in their
history, someone correct me. That might make this pretty rare on that
front as well.
thanks
Jim
Beautiful-1974-NATIONAL-SEMICONDUCTOR-COMPUTER-model-imp-16p/
http://www.ebay.com/itm/252700755919
> From: Pete Lancashire
> To convert from Muncell to RGB
Interesting. For one colour (D.C. Blue), listed on Charles' page as Munsell
5PB 3/10, that page gives it as 'outside sRGB gamut', whereas the page you
list gives it as sRGB [0,72,145].
Noel
> From: Antonio Carlini
> My scan is ~400MB (and 1090 pages long!)
Even at 1K pages, it shouldn't be anything like that big, if scanned using
the most space-efficient encoding.
For _manuals_, scan at 300 dpi with Black+White encoding (i.e. 1 bit per
pixel), then store as TIFFs with CCITT Group 4 (fax) compression. That does a
typical page of text in ~45KB or so. So you're about an order of magnitude
high....
(For engineering drawings, basically the same, except scan at 600 dpi, to
capture all the small characters such as pinouts.)
Noel
Hi folks,
Happy new year to all!
Is anyone here familiar with the innards of Viewdata? I'm still deep in the
bowels of this Executel viewdata phone system and one thing that it should
be doing but isn't is puzzling me.
The teletext chip is a Plessey MR9735, datasheet here:
http://www.binarydinosaurs.co.uk/mr9735.pdf
It can work in either 'off hours' or 'on hours' meaning effectively 'day' or
'night' mode when there's no broadcast TV signal at night, this is the 80s
remember.
The surrounding circuitry forces Off Hours by pulling high all the incoming
TV signals apart from Line Flyback which is pulled low. The datasheet says:
"When the incoming transmission is turned off, (i.e. Goes 'Off-hours'), this
is recognised by the [On Hours Detector] after at least 300ms of missing
sync. Pulses. An internally generated Composite Sync signal is then switched
to the Composite Sync Out pin."
Since Sync In is pulled high there are never any negative sync pulses (I've
watched this on a logic analyser) so after 300ms Sync Out should become an
internally generated pulse, but this doesn't happen and Sync Out remains a
steady 5V meaning the TV picture is unsync'd.
I know the MR9735 itself is fine as I have a pair of Tandata viewdata
terminals which also use this chip in Off Hours mode and I can swap them
around. The chip itself is receiving a steady 6MHz clock to pin 21 and the
clock divider outputs at pins 20 and 19 are working.
Any clues?
--
Adrian/Witchy
Binary Dinosaurs creator/curator
Www.binarydinosaurs.co.uk - the UK's biggest private home computer
collection?
Rod,
On Thu, Dec 29, 2016 at 8:04 PM, Rod Smallwood
<rodsmallwood52 at btinternet.com> wrote:
> Hi Guys
>
> I have had a quick word with the girls down at the silk screen
> shop.
A couple of years ago I tried to translate the DEC color standards to
RGB based on the colors in the standards on bitsavers. Here is what I
came up with:
http://www.chdickman.com/pdp8/DECcolors/
I think I posted this already.
How have you been doing your color matching? Have you published a
color list for the panels you have made? I am thinking about color
matching for switch handles for example that are in the same colors.
Some enduring standard translation for the colors would be great to
have available in the future.
I never imagined how slippery color was until I tried to do the color
matching from the DEC standards. I had to meet Munsell, Ostwald and
the CHM (Color Harmony Manual, not the Computer History Museum),
before I was done. And Pantone seems to be the Microsoft of color.
-chuck
I've updated my VHDL 1802 core and COSMAC ELF for a newer FPGA, the Xilinx
Artix 7. As usual, the source code in in the github repository:
https://github.com/brouhaha/cosmac/
On the XC7A100T-1FGG484, which is the slowest speed grade, it meets timing
at 62.5 MHz. Since my 1802 core only needs one clock per machine cycle,
versus 8 for the original CDP1802, it runs at the equivalent of a 500 MHz
CDP1802.
I was actually able to run it at 100 MHz (800 MHz equivalent), but that
doesn't meet timing so there's no guarantee that it will work; it is
"overclocking" the FPGA. I can't really imagine any reason to need an 800
MHz equivalent CDP1802. :-)
It has been tested with a few simple test programs and with CamelForth.
The interrupt support and related instructions are still untested.
Eric
