Looking for Limited Function Board

[Anders Sandahl]

Hi,

I have looked into my PDP-8/a computers now. The small one have the
limited function board that you want. That is the machine that should be
identical to yours.

In my big PDP-8a/420 I have the same board as you have "have.jpg" but in
another revision (no IDC header connector, just the DIL connector).

The big machine is a core memory machine. I had a quick look at the
schematics, they are not compatible.

/Anders

> Hi Paul
>
> I have put pictures of the boards here:
>
> http://pdp8.se/slask/LFB
>
> have.jpg is the board I have and want.jpg is the one
> I'm looking for.
>
> The identifying numbers are in aproximately the same
> place. But you can clearly see that the "want" board
> is much simplified and if I interpret the
> documentation correctly they are not compatible.
>
> I'm happy to be proven wrong, maybe I should just try
> it.
>
> /P
>
>
> On Tue, Feb 05, 2019 at 07:54:39PM -0600, Paul Anderson via cctalk wrote:
>> Hi Pontus,
>>
>> I looked at my limited function front panels, and they were 54-11507s. I
>> have not looked at any prints. Where did you find the 54-11165 number?
>> Could it be for a Q-bus system?
>>
>> The 50-XXXXX is the etched PCB. DEC usually added a 1 to that number to
>> make it complete board.
>>
>> Thanks, Paul
>>
>>
>>
>> On Mon, Feb 4, 2019 at 9:41 PM Paul Anderson <useddec at gmail.com> wrote:
>>
>> > I have a few of the limited function and programmers panels. I do not
>> > recall either of them being dependent on particular backplane. I'll
>> try to
>> > pull a few a few later and check the part number on them.
>> >
>> > Remember, a 54-XXXXX number can become a 70-XXXXX with the addition of
>> a
>> > cable or something simple.
>> >
>> > Paul
>> >
>> > On Mon, Feb 4, 2019 at 12:51 PM Anders Sandahl via cctech <
>> > cctech at classiccmp.org> wrote:
>> >
>> >> > Date: Sun, 3 Feb 2019 22:22:42 +0100
>> >> > From: Pontus Pihlgren <pontus at Update.UU.SE>
>> >> > To: "General Discussion: On-Topic and Off-Topic Posts"
>> >> >       <cctalk at classiccmp.org>
>> >> > Subject: Looking for Limited Function Board
>> >> > Message-ID: <20190203212242.GF24947 at Update.UU.SE>
>> >> > Content-Type: text/plain; charset=us-ascii
>> >> >
>> >> > Hi
>> >> >
>> >> > I'm restoring a PDP-8/a with the help of some
>> >> > friends. The CPU is now passing the MAINDECs I've
>> >> > thrown at it. The memory is a modern semiconductor
>> >> > board my friend Anders Sandahl made.
>> >> >
>> >> > This machine is pieced together from several others
>> >> > and the limited function panel I got does not match
>> >> > the backplane I have.
>> >> >
>> >> > My theory is the DEC simplified the design of the
>> >> > boardto cut costs and simpler design is not
>> >> > compatible. Mine is labeled (on the PCB):
>> >> >
>> >> > "LIMITED FUNCTION BD.
>> >> > 5411507
>> >> > 5011506C-P2"
>> >> >
>> >> > And the one I need is:
>> >> >
>> >> > "LIMITED FUNCTION
>> >> > 5411165
>> >> > 5011167"
>> >> >
>> >> > However, the picture I have of the other is not so
>> >> > good. I may have read the numbera wrong.
>> >> >
>> >> > I would very much like to buy one to finish this
>> >> > project.
>> >> >
>> >> > /P
>> >>
>> >> Får du inget napp så ritar jag upp ett kort till dig, det borde gå
>> att
>> >> flytta över brytarna från det du har. Lite synd att scrappa ett
>> >> originalkort bara, men är man försiktigt så man inte tar sönder det
>> så går
>> >> det ju att återställa...
>> >>
>> >> /A
>> >>
>> >>
>