Re: Weird Lear-Siegler ADM-3A board

[Eric Smith via cctalk]

On Tue, May 29, 2018 at 1:10 AM, Eric Smith  wrote:

> On Fri, May 25, 2018 at 3:30 PM, Adrian Graham via cctalk <
> cctalk@classiccmp.org> wrote:
>
>> Wow, good spot! This one isn’t badged but we just assumed it had fallen
>> off. Just as I’m typing this he’s messaged me to say it’s actually the
>> ADM-3A ‘10th Anniversary edition’. The manual is on bitsavers:
>>
>
> It might have _started_ its life as an ADM-3A 10th Anniversary Edition,
> but it isn't one any more. The PCB in the photo is the Zentec ADM3 Retrofit.
>

I may have been completely wrong about that. When I wrote that, I wasn't
aware that Zentec bought the terminal product line from Lear Siegler in
1986, and continued making some of the terminals, including the ADM-3A,
under the Zentec name. Since the LSI ADM-3A was introduced in 1976, It's
possible that Zentec introduced the ADM-3A 10th Anniversary Edition with
the NS405-based logic board.

Eric

Re: Weird Lear-Siegler ADM-3A board

[Eric Smith via cctalk]

On Wed, Jun 6, 2018 at 12:42 PM, Kyle Owen via cctalk  wrote:

> I have this development board with an NS405 on it. Checked through my docs
> and don't seem to have anything for it. Would dumping the EPROM be of
> interest?
>

>From the hand-written label on the EPROM, I suspect that it's not the
original code the development board shipped with, but sure, it would still
be interesting to look at the code.

Re: Weird Lear-Siegler ADM-3A board

[Kyle Owen via cctalk]

On Wed, Jun 6, 2018, 12:52 Eric Smith via cctalk 
wrote:

> Sure, if you've got them handy, I'll try compiling them with FPC. Are you
> willing to release them as open source?
>
> Do you have any actual NS405/NS455 code that would be of interest?
>

I have this development board with an NS405 on it. Checked through my docs
and don't seem to have anything for it. Would dumping the EPROM be of
interest?

http://imgur.com/a/zYJvN5B

Thanks,

Kyle

>

Re: Weird Lear-Siegler ADM-3A board

[Eric Smith via cctalk]

On Tue, Jun 5, 2018 at 7:38 PM, Jon Elson  wrote:

> I wrote a disassembler for the NS405/NS455 in Pascal on my CP/M system, in
> 1985.
> If this code would be of any use, I can let you have it.  I'm guessing
> this was written for the UCSD Pascal system as run under CP/M.  I have no
> idea how easy it would be to get it running on a modern Pascal compiler.  I
> have had really good luck bringing up some old Pascal programs from Borland
> Turbo pascal and VAX Pascal with the Linux FPC (Free Pascal Compiler).
>
> I also have a cross-assembler for the NS405/455 written in Pascal.


Sure, if you've got them handy, I'll try compiling them with FPC. Are you
willing to release them as open source?

Do you have any actual NS405/NS455 code that would be of interest?

Re: Weird Lear-Siegler ADM-3A board

[Jon Elson via cctalk]

On 06/05/2018 07:15 PM, Eric Smith via cctalk wrote:

On Tue, Jun 5, 2018 at 1:30 PM, Noel Chiappa via cctalk <
cctalk@classiccmp.org> wrote:


This is now available through here:
   http://gunkies.org/wiki/Term-Mite_ST_Smart_Terminal


Thanks!

If someone dumps the ROM of the Zentec ADM3 Retrofit, I'll try my hand at
reverse-engineering the code.

I wrote a disassembler for the NS405/NS455 in Pascal on my 
CP/M system, in 1985.
If this code would be of any use, I can let you have it.  
I'm guessing this was written for the UCSD Pascal system as 
run under CP/M.  I have no idea how easy it would be to get 
it running on a modern Pascal compiler.  I have had really 
good luck bringing up some old Pascal programs from Borland 
Turbo pascal and VAX Pascal with the Linux FPC (Free Pascal 
Compiler).


I also have a cross-assembler for the NS405/455 written in 
Pascal.


Jon

Re: Weird Lear-Siegler ADM-3A board

[Noel Chiappa via cctalk]

> Jon Elson

> How/where should I submit this? 

This is now available through here:

  http://gunkies.org/wiki/Term-Mite_ST_Smart_Terminal

I put in a little infrastructure around it (articles on the Term-Mite, NS405,
etc), using info I dug up online.

Noel

Re: Weird Lear-Siegler ADM-3A board

[Adrian Graham via cctalk]

> On 29 May 2018, at 08:10, Eric Smith  wrote:
> 
> On Fri, May 25, 2018 at 3:30 PM, Adrian Graham via cctalk 
> mailto:cctalk@classiccmp.org>> wrote:
> Wow, good spot! This one isn’t badged but we just assumed it had fallen off. 
> Just as I’m typing this he’s messaged me to say it’s actually the ADM-3A 
> ‘10th Anniversary edition’. The manual is on bitsavers:
> 
> It might have _started_ its life as an ADM-3A 10th Anniversary Edition, but 
> it isn't one any more. The PCB in the photo is the Zentec ADM3 Retrofit.
> 


Ah right, that’s good to know for any troubleshooting we may need to do in the 
future! For now it’s working nicely though.

Cheers,

-- 
adrian/witchy
Owner of Binary Dinosaurs, the UK's biggest home computer collection?
t: @binarydinosaursf: facebook.com/binarydinosaurs
w: www.binarydinosaurs.co.uk

Re: Weird Lear-Siegler ADM-3A board

[Noel Chiappa via cctalk]

> From: Eric Smith

> The NS455 has firmware in masked ROM ...  The NS405 has the masked ROM
> disabled

Ah, thanks muchly! Do you know of _any_ documentation extant for the 455? I
couldn't find anything..

> I've been searching for the NS405 manual (not the datasheet) for a very
> long time.

The data sheet seems pretty complete - are you sure there ever was a manual?

Noel

Re: Weird Lear-Siegler ADM-3A board

[Eric Smith via cctalk]

On Fri, May 25, 2018 at 3:30 PM, Adrian Graham via cctalk <
cctalk@classiccmp.org> wrote:

> Wow, good spot! This one isn’t badged but we just assumed it had fallen
> off. Just as I’m typing this he’s messaged me to say it’s actually the
> ADM-3A ‘10th Anniversary edition’. The manual is on bitsavers:
>

It might have _started_ its life as an ADM-3A 10th Anniversary Edition, but
it isn't one any more. The PCB in the photo is the Zentec ADM3 Retrofit.

Re: Weird Lear-Siegler ADM-3A board

[Eric Smith via cctalk]

On Fri, May 25, 2018 at 1:58 PM, Adrian Graham via cctalk <
cctalk@classiccmp.org> wrote:

> Hi folks,
>
> A friend of mine has said ADM-3A and is baffled by the tiny board it
> contains, not the usual ‘covering entire base’ discrete logic board they
> normally have. Centre of this board is the Nat Semi NS405 ‘display
> processor on a chip’ which is obviously why the board is so small but
> neither of us have seen this before in a 3A.
>
> Anyone else? Pic at http://www.binarydinosaurs.co.uk/tonyADM3a.jpg <
> http://www.binarydinosaurs.co.uk/tonyADM3a.jpg>
>

That's the Zentec ADM3 retrofit:
http://bitsavers.trailing-edge.com/pdf/zentec/Zentec_ADM3_Retrofit/

Re: Weird Lear-Siegler ADM-3A board

[Eric Smith via cctalk]

On Sun, May 27, 2018 at 3:10 PM, Noel Chiappa via cctalk <
cctalk@classiccmp.org> wrote:

> I decided I'd do an article about the Term-Mite for the CHWiki; I found
> Ciarcia's long article about the Term-Mite (in his book, which Google books
> has); it talks throughout the article about the NS455 - but it also says
> "[t]he Term-Mite actually uses a NS405 chip which is a specialized version
> of
> the generic NS455".
>

The NS455 has firmware in masked ROM, which it uses if the EA pin is low.
If EA is high (min spec 3.8V, normally tied directly to Vdd), external
memory (usually ROM or EPROM) must be used instead.

The NS405 has the masked ROM disabled, so external firmware must be used,
and EA must be tied high. It is actually the same die with unspecified ROM
content, so it probably would execute some sort of internal firmware if EA
was low, but that might or might not be the same as the standard NS455
firmware; it could be firmware from a custom version of the NS455, or test
firmware, or (less likely) any of the above but with some errors due to
mask defects.

I've been searching for the NS405 manual (not the datasheet) for a very
long time.

Re: Weird Lear-Siegler ADM-3A board

[Noel Chiappa via cctalk]

> From: Jon Elson

> Steve Ciarcia ...  made a board using the NS405 called the Term-Mite.

I decided I'd do an article about the Term-Mite for the CHWiki; I found
Ciarcia's long article about the Term-Mite (in his book, which Google books
has); it talks throughout the article about the NS455 - but it also says
"[t]he Term-Mite actually uses a NS405 chip which is a specialized version of
the generic NS455".

So I went to look up the 405 and 455, to see what the difference was between
the 405 and the 455. I found a data sheet for a 405, but not one for the 455.
Does anyone know where I can find info about the 455 (or, better, yet, know
what the difference is between the two - that would save me some leg-work).

Thanks (I hope :-)!

Noel

Re: Weird Lear-Siegler ADM-3A board

[Jon Elson via cctalk]

On 05/25/2018 04:43 PM, Al Kossow via cctalk wrote:

Getting a prom dump would be cool.

Steve Ciarcia of Byte and Circuit Cellar fame made a board 
using the NS405 called the Term-Mite.
I have a file that says it has a very small patch to tweak 
the sync timing, and that is was disassembled by my own 
disassembler.  But, I don't believe it, as it has EXTENSIVE 
comments, like every second line.
I no longer remember how I got this file, but I'm guessing 
Steve distributed the source with the board.


How/where should I submit this?  It is 24.6K

Jon

Re: Weird Lear-Siegler ADM-3A board

[Jon Elson via cctalk]

On 05/25/2018 02:58 PM, Adrian Graham via cctalk wrote:

Hi folks,

A friend of mine has said ADM-3A and is baffled by the tiny board it contains, 
not the usual ‘covering entire base’ discrete logic board they normally have. 
Centre of this board is the Nat Semi NS405 ‘display processor on a chip’ which 
is obviously why the board is so small but neither of us have seen this before 
in a 3A.

Anyone else? Pic at http://www.binarydinosaurs.co.uk/tonyADM3a.jpg 



That looks a bit like a clone of the Term-Mite development 
board for the NS405.
I suspect somebody just used the ADM-3A housing, monitor and 
maybe power supply components

to hold their updated terminal.

Jon

Re: Weird Lear-Siegler ADM-3A board

[Phil Budne via cctalk]

Looks to me like the circuit board says "ADM 3R"

Re: Weird Lear-Siegler ADM-3A board

[Al Kossow via cctalk]

Getting a prom dump would be cool.


On 5/25/18 12:58 PM, Adrian Graham via cctalk wrote:
> Hi folks,
> 
> A friend of mine has said ADM-3A and is baffled by the tiny board it 
> contains, not the usual ‘covering entire base’ discrete logic board they 
> normally have. Centre of this board is the Nat Semi NS405 ‘display processor 
> on a chip’ which is obviously why the board is so small but neither of us 
> have seen this before in a 3A.
> 
> Anyone else? Pic at http://www.binarydinosaurs.co.uk/tonyADM3a.jpg 
> 
> 
> cheers!
> 

Re: Weird Lear-Siegler ADM-3A board

[Adrian Graham via cctalk]

> On 25 May 2018, at 22:04, Adam Sampson via cctalk  
> wrote:
> 
> Adrian Graham via cctalk  writes:
> 
>> A friend of mine has said ADM-3A and is baffled by the tiny board it
>> contains, not the usual ‘covering entire base’ discrete logic board
>> they normally have.
> 
> Here's a similar one that was on eBay a couple of years ago (the full
> listing has pictures of the insides):
>  https://www.ebay.co.uk/itm/-/322312097162
> 
> The September 1986 date on the case of yours means that it dates from
> around the time when Lear-Siegler sold their terminal business to
> Zentec -- is it actually badged Lear-Siegler?


Wow, good spot! This one isn’t badged but we just assumed it had fallen off. 
Just as I’m typing this he’s messaged me to say it’s actually the ADM-3A ‘10th 
Anniversary edition’. The manual is on bitsavers:

http://bitsavers.trailing-edge.com/pdf/learSiegler/ADM_3/DP2880486F_ADM3A_UM_Apr86.pdf
 


I do love a happy ending to a search :) Cheers!

-- 
adrian/witchy
Owner of Binary Dinosaurs, the UK's biggest home computer collection?
t: @binarydinosaursf: facebook.com/binarydinosaurs
w: www.binarydinosaurs.co.uk

Re: Weird Lear-Siegler ADM-3A board

[Adam Sampson via cctalk]

Adrian Graham via cctalk  writes:

> A friend of mine has said ADM-3A and is baffled by the tiny board it
> contains, not the usual ‘covering entire base’ discrete logic board
> they normally have.

Here's a similar one that was on eBay a couple of years ago (the full
listing has pictures of the insides):
  https://www.ebay.co.uk/itm/-/322312097162

The September 1986 date on the case of yours means that it dates from
around the time when Lear-Siegler sold their terminal business to
Zentec -- is it actually badged Lear-Siegler?

-- 
Adam Sampson  

Weird Lear-Siegler ADM-3A board

[Adrian Graham via cctalk]

Hi folks,

A friend of mine has said ADM-3A and is baffled by the tiny board it contains, 
not the usual ‘covering entire base’ discrete logic board they normally have. 
Centre of this board is the Nat Semi NS405 ‘display processor on a chip’ which 
is obviously why the board is so small but neither of us have seen this before 
in a 3A.

Anyone else? Pic at http://www.binarydinosaurs.co.uk/tonyADM3a.jpg 


cheers!

-- 
adrian/witchy
Owner of Binary Dinosaurs, the UK's biggest home computer collection?
t: @binarydinosaursf: facebook.com/binarydinosaurs
w: www.binarydinosaurs.co.uk