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mytek

Wanted: ICD RAMBO XL Schematic

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Posted (edited)

I installed an original ICD RAMBO XL into one of my 1200XLs and really like how easy it was to do. However I'm not really fond of the 4 extra wires that are scattered across the PCB (A,B,C,D), nor the fact that I had to file down the pins on a header so as to use it for the PBx signals. Ideally I want everything to utilize a header connection so that it's easily removable down the road. So my plan is to make up a small batch of RAMBO XL clone boards that uses a right angle header for all the wire connections.

 

Original

ICD_RAMBO_XL_PCB_part_placement.thumb.png.b8daccd419690ddaface7bbbf3dd840d.png

 

Proposed

image.png.a4a87590e1b740ef1516d1981a3201b4.png

 

 

Now I could trace out the connections on my one and only already installed board, but would prefer to start from an existing schematic. Does anyone know where I could find one?

 

I believe this board was cloned by @Dropcheck and sold on her website for a limited time, so that suggests that there may be a schematic out there.

 

As usual, whatever PCB I end up designing, will have the gerbers released to the public.

 

ICD Manual: RamboXLManual.pdf

 

Edited by mytek
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Hello Michael

 

Would it be possible to turn this into a PCB that would plug between the PIA and the socket the PIA was in?  That would reduced the amount of solder connections that would have to be made at the time of installation.

 

It would also make it possible to turn the PCB into a Compyshop compatible upgrade via either a jumper or a switch.  You'd create one 256kB upgrade (PCB) that can be used as a RAMBO and as a Compyshop compatible upgrade.

 

Sincerely

 

Mathy

 

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Posted (edited)
22 minutes ago, Mathy said:

Hello Michael

 

Would it be possible to turn this into a PCB that would plug between the PIA and the socket the PIA was in?  That would reduced the amount of solder connections that would have to be made at the time of installation.

 

It would also make it possible to turn the PCB into a Compyshop compatible upgrade via either a jumper or a switch.  You'd create one 256kB upgrade (PCB) that can be used as a RAMBO and as a Compyshop compatible upgrade.

 

Sincerely

 

Mathy

 

I have a 320k board being made now.  I might have it in to test by next week.  The simulation looks good.  It should work by just plugging it into the parallel port.  The 800xl will need a USB-C power supply for it's 5vdc.

 

Edit:  Yeah, this won't work on a 1200XL.  It's too bad they didn't put a parallel port on a 1200XL...and too bad there's no /halt signal on the PBI...

Edited by reifsnyderb

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Posted (edited)

I looked through all my blueprints I've been able to find and don't have anything on the Rambo XL.  Sorry. 

 

If you do end up tracing out the board you have, I don't know if you have any logic simulation to run a test on the circuit or not.  I've been using the program "Digital" by H. Neemann as it not only allows for testing of logic circuits but can be used to setup Atmel CPLD's.  (12 maximum outputs only...don't ask me how I learned this.)  It's a free download and it works pretty well to do a sanity check before ordering a board.

Edited by reifsnyderb

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43 minutes ago, Mathy said:

Would it be possible to turn this into a PCB that would plug between the PIA and the socket the PIA was in?  That would reduced the amount of solder connections that would have to be made at the time of installation.

Hi Mathy - It would cut the number of connections in half but also limit it to a 1200XL since the other glue logic chip it needs to plug into wouldn't be in the same location on other systems. Although maybe those connections are present from the PIA socket also (I'll have to check the 1200XL schematic)

 

43 minutes ago, Mathy said:

It would also make it possible to turn the PCB into a Compyshop compatible upgrade via either a jumper or a switch.  You'd create one 256kB upgrade (PCB) that can be used as a RAMBO and as a Compyshop compatible upgrade.

Nice idea, but I think that's getting outside my pay grade at the moment. Besides I really want this to be a quick, easy, fast turn-around project that I can use on another 1200XL I just received from Bob, and also replace the 'real' RAMBO XL board in my 1st 1200XL that it presently has installed. Not looking at trying to take on X,Y and Z features (I'll leave that to someone else).

 

26 minutes ago, reifsnyderb said:

I looked through all my blueprints I've been able to find and don't have anything on the Rambo XL.  Sorry. 

Thanks for looking 👍

 

26 minutes ago, reifsnyderb said:

If you do end up tracing out the board you have, I don't know if you have any logic simulation to run a test on the circuit or not.  I've been using the program "Digital" by H. Neemann as it not only allows for testing of logic circuits but can be used to setup Atmel CPLD's.  (12 maximum outputs only...don't ask me how I learned this.)  It's a free download and it works pretty well to do a sanity check before ordering a board.

Sounds interesting, but this is such a simple board, tracing should be fairly easy. No need for simulation, since I know if copied accurately it will work.

 

14 minutes ago, Ricky Spanish said:

Nice ! Definitely will get one, but first I have to find/buy a 1200XL, so far no luck :(

I know a guy that has quite a few, although most need work (keyboard fix for one). Maybe check with @bob1200xl to see if he is interested in selling any of his collection. I know a while back he was asking what people needed, and was trying to help them out.

 

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53 minutes ago, mytek said:

I know a guy that has quite a few

If you could look into that for me that'd be awesome ! I'll message bob1200xl as well, thanks !

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4 hours ago, Ricky Spanish said:

If you could look into that for me that'd be awesome ! I'll message bob1200xl as well, thanks !

They're one in the same ;)  Bob is the guy.

 

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Thanks, @1050. The 1200XL has a different pinout for the LS158 which is called U27 in the 800XL. I think ICD added jumper blocks to compensate. So you should trace out that part of the circuit at least.

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5 hours ago, 1050 said:

From this post

https://atariage.com/forums/topic/122470-ram-upgrade-applications/page/2/?tab=comments#comment-1481893

 

I believe it to be the only form of it ever published in the wild as I've not seen either a whizz or ICD version anywhere, but the above is it just the same.

Thanks for posting that, lot's of good info at that link.

 

2 minutes ago, ClausB said:

Thanks, @1050. The 1200XL has a different pinout for the LS158 which is called U27 in the 800XL. I think ICD added jumper blocks to compensate. So you should trace out that part of the circuit at least.

Yeah I figured as much, and remembered someone mentioning that ICD's version of your design differed in being able to be configured for a 1200XL (and you can see the jumpers on their board). So I'll trace my genuine RAMBO XL board, compare it to your schematic as a double check, and produce a new schematic based on the combination.

 

Thanks to both you and 1050 for the assistance :)

 

Although I was kinda hoping that someone who already had the RAMBO XL schematic or a clone of it would post it. None the less I will gladly post mine when I get it drawn.

 

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Rambo was groundbreaking in the day.  ICD, a quality company, great products and great customer support.  It was the very first RAM upgrade I installed.  Still working today 35 years later.  Rockford, IL.  ICD, I salute your past.  Anyone on this site that used to work for them?  I did buy a Dropcheck reimaged one and it works well too.   Thanks to all.  One without the wires would be even better.  256K is all I have ever needed, and its fully bank switched, XE compatible. 

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19 minutes ago, gilsaluki said:

ICD, I salute your past.  Anyone on this site that used to work for them?

You're welcome.

 

I worked for them and didn't know it. I put my design into public domain and they produced it.

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25 minutes ago, ClausB said:

You're welcome.

 

I worked for them and didn't know it. I put my design into public domain and they produced it.

Wow!  That is a story that needs to be told.  I think that warrants further discussion.  Sounds like you were the intellectual property owner (public domain aside).  No royalties for you, I am guessing.  Anyways, thanks!  I have enjoyed your work for over three decades.  You made an impact!

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Posted (edited)

Thanks for the kind words. The thread linked in 1050's post above tells the story.

Edited by ClausB
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I think this is right...

 

RamboXL was designed for both the 1200XL and the 800XL. A lot of the circuits on the PCB are to set up the 1200XL with 8 bits of refresh. Actually, some 800XLs needed 8 bit refresh if they used the xxx96 ANTIC chip. Bottom line is that you can set up RAMBO in a 1200XL using the 800XL configuration and the xx97 ANTIC.

 

Bob

 

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As I recall, perhaps incorrectly, Rambo did not allow separate antic banking.  And the Newell upgrade did.  Maybe.   

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Here's my first stab at recreating the ICD RAMBO XL schematic.

 

RAMBO_XL-II_schema.thumb.png.f12422e40f6a8cd02d7b53eba0362684.png

I'll have to double check this before I commit to making a PCB layout, and if anyone sees a glaring mistake please let me know.

 

Now as can be seen there are numerous signals being picked up from either U7 (1200XL) or U27 (800XL) that simply are not available from the PIA chip. So to try to make a no-solder version of this would require piggy backing at a bare minimum the PIA and the 74LS158 (U7 or U27), and on a 1200XL you would still be left with 4 wires to connect (1 wire for the 800XL). So I think it's best to keep this close to what ICD produced, although I am going to have all wired connections via header J4.

 

 

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First check against my schematic looks good, except J1 label may be incorrect. Looks like pins 1 and 2 should connect for 800XL mode. I haven't checked the 1200 mode yet.

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34 minutes ago, ClausB said:

First check against my schematic looks good, except J1 label may be incorrect. Looks like pins 1 and 2 should connect for 800XL mode. I haven't checked the 1200 mode yet.

Yep you are correct, I got that shown backwards. Easy fix :)

 

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7 hours ago, ClausB said:

I worked for them and didn't know it. I put my design into public domain and they produced it.

 

Wow, that's amazing! Are you sure they actually copied your design? May be they just came up with a very similar design by themselves? I know that doesn't sound very likely, but this kind of things sometimes does happens. And it's also hard to understand why they would copy a design.

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59 minutes ago, ijor said:

Are you sure they actually copied your design? May be they just came up with a very similar design by themselves?

Well if they didn't copy it, then it's a case of great minds think a like, because it not only has the same ICs, but used the same pins in each package, and the same chip IDs.

 

---------

 

Well I'll admit it, I'm blatantly copying ICDs board while making a minor refinement ;)

 

Here's the layout in what should be its final parts placement.

 

image.png.bf2dac96954cf6353c9cc1c230bf6775.png

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37 minutes ago, mytek said:

Well if they didn't copy it, then it's a case of great minds think a like, because it not only has the same ICs, but used the same pins in each package, and the same chip IDs.

 

Ah, no, I thought it was very similar but not that identical. Unbelievable!

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