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1450 XLD motherboard build, assorted questions


Vandal968

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Well, Corey and I are working on the bottom case and side piece, once he's got them into CAD format, I'll see what kind of costs some tooling will be based on the IGS files and we'll go from there, the Mobo's shouldn't be too crazy to have a run done, first I need to get a firm that still works with films to scan them in and generate some gerber files and then we'll see what it'll cost to run a 4 layer board, its pretty big, so I would assume it's gonna be pricey, but we'll see, I may have to bite the bullet on the PCB's and look to have them down over in China due to cost, but if I do that, it's the difference between them costing $100 and costing maybe $20, so again we'll see... first things first, lets get the files made.... I need more hours in a day, 24 just ain't enough!

Any new news on this Curt?

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  • 2 weeks later...

 

An advantage of the 1200XL is that it's not so absolutely priceless (yet) as to prohibit upgrades, so you can have a machine which looks as good as a 1400XL, but is more powerful.

I have a very heavily modded 1200XL that I used until I got my 800 upgraded with Incognito. I still waffle back and forth as to which one to use. Even though my 800 is now more powerful than my 1200XL (having a built in SIDE loaded and more OS/memory configurations), there's just something sexy about the 1200XL.

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Even though my 800 is now more powerful than my 1200XL (having a built in SIDE loaded and more OS/memory configurations), there's just something sexy about the 1200XL.

 

Totally agree. This very thread was the inspiration behind the modding I did to my 1200XL, which I hadn't really known what to do with having finally obtained it. I called it "The poor man's 1400XL" when I started blogging about it, and it's now by far the most powerful A8 I own (U1MB, VBXE, Stereo, PAL, internal IDEa with custom APT BIOS, widened cart tunnel for SIDE2). I seriously doubt I'd have wanted to perform such modifications on a 1400XL. :D

 

I just fitted the NOS keyboard I've had in the cupboard for a couple of years, too, so now all the console keys are extra shiny. :)

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I want a 1450XLD board to start from.

 

I hacked all my Atari gear to do more...

 

I would have replaced the 300baud modem with plugin card to make a 28.8kbaud or more by the mid 90's

 

I'd have likely done at least 320kbyte memory upgrade.

 

Expect it would have had a PBI HD inside by now as well.

 

As I'm pretty much retired now, I've dug all my Atari stuff that was in storage out and am now looking for new things to try.

 

--

 

 

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I actually have a 1400XL board I got from Best years ago. How hard is it to make one of these into an honest to goodness 1400XL? I imagine some of the parts are getting hard to find. Then again, what does a 1400XL offer over a 1200XL other than a built in modem, voice synth, and some other stuff like a PEB (already have it), and FREDDY chip (not particularly useful)?

 

EDIT: Well what do you know, looking at it again it's actually a 1450 motherboard. It says:

 

ATL V-0

C024355-001 REV X2

Copyright 1983 Atari

 

I imagine making a 1450XLD would be super tough because of the missing required daughter board. Still, a guy can dream I guess. :)

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I expect it would be a great build and a fair amount of work... Then likely finding a set of 1200xl plastics to build a case from.

 

But what I want to do with it is build it into the system that Atari should have released to us in the mid 80's

 

Freddy with 64K main, 256K/512K banked. No built in BASIC. 65816 CPU on a daughterboard with 1M/2M fast RAM in high pages for the 16bit mode. Upgradable. Maybe some OS ROM up there as well

 

The PBI floppy controller should be based around a WD1772 FDC with it's own RAM and a small CPU. 6507 or maybe a 6800 or 6809. Were there smaller address buss versions of those? Bootstrap ROM, 6K of RAM plus hardware mapping would easily fit in the 6507 address space.

 

Upgrade the modem with a daughterboard. At least 9600baud, but I can see going faster. Maybe another 6507 to run the modem.

 

Instead of loading everything on the CPU, play to Atari strong point... Multi-Proccessing. ANTIC is a second CPU. Why not more?

 

Backwards compatable... OS must run properly written XL/XE software without mods. Should run most 400/800 as well.

 

Want to sell? :evil: :evil:

 

--

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  • 1 month later...

In case others haven't seen it, there's a 1450 mobo for sale in the marketplace : http://atariage.com/forums/topic/226216-atari-8-bit-hardware-for-sale/?do=findComment&comment=3005627

 

I don't think I'll be able to afford to buy it myself, but maybe someone else here that has shown interest in building one can have a chance to build it up...

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  • 7 months later...
  • 2 years later...
  • 3 years later...

Hi All,

 

I finally got back to this project that was almost done, and got the handler EPROM and the PAL 'C' chip burned and populated (the last chips I needed) and built a power supply from an old PC ATX power supply.  However, turned it on with great trepidation... and got just a black screen.  I am getting the correct voltages on the motherboard I believe.

 

What I suspect, and pretty much expected, is that I don't think I have the correct PAL 'A' chip.  I ordered this from Best Electronics years and years ago, I don't think I was actually sent the correct part.  It's a PAL16L8, but does not have the C061919 label, it's labeled with C080509 or C080609, its very hard to read as it's quite small and not very clear.

 

Can anyone send me the JEDEC file for the PAL 'A' U12 chip from their 1450XL?

 

Hopefully that will be all the issue is for this board.  *fingers crossed*

 

 

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On 2/24/2021 at 9:46 PM, AtariGeezer said:

C080509 or C080609 doesn't come up on a google search.  Haven't seen a JEDEC file for the PAL 'A' U12 chip.

Can you take a pic of the one from Best Electronics?

 

I took a picture and attached it here.

 

I was hoping someone who has a working one could dump it, especially if the files don't exist somewhere on-line already.  Looking over at Atari Museum, is this the chip description:

http://www.atarimuseum.com/computers/8bits/xl/1450xld/1450XLD_GATE_ARRAY-BARBARA.pdf

 

 

atari-bad-chip.jpg

Edited by Shawn Jefferson
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On 2/27/2021 at 7:37 PM, kheller2 said:

Barbara was for the TONG motherboard version of the 1450XLD from 1984.  You probably want these 1400-PAL_Chips-and-Equations.PDF

 

I wonder... as these boards are the 1450 boards that were created later on.  Hopefully this is the correct equations, and I guess I'll have to try and figure out how to program a chip with these then.

 

Hoping someone with a working 1450 board may dump the chip for me, as at least we know that it will be correct in that case! :)

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12 minutes ago, Shawn Jefferson said:

 

I wonder... as these boards are the 1450 boards that were created later on.  Hopefully this is the correct equations, and I guess I'll have to try and figure out how to program a chip with these then.

 

Hoping someone with a working 1450 board may dump the chip for me, as at least we know that it will be correct in that case! :)

 

Bob dumped one of them here: 

 

 

 

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  • 3 weeks later...
On 2/27/2021 at 12:55 AM, Shawn Jefferson said:

 

I took a picture and attached it here.

 

I was hoping someone who has a working one could dump it, especially if the files don't exist somewhere on-line already.  Looking over at Atari Museum, is this the chip description:

http://www.atarimuseum.com/computers/8bits/xl/1450xld/1450XLD_GATE_ARRAY-BARBARA.pdf

 

 

atari-bad-chip.jpg

 

This chip is the CO60609 (1200XL MMU) I found out.  The writing is very small and blurred, so hard to tell, but I have verified that now.  It's definitely not the PAL A chip that I need.  I have been doing some research into these PAL chips, and working on getting them built from the equations.  I will start a new thread for that, as there's a few interesting things there.

 

I still need PAL A, and now I've discovered that I also need PAL C made properly, as the one I had programmed doesn't seem to be correct.  I was able to verify my PAL B is correct though.

 

 

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