1088XLD - Custom A8 Computer in 1050 Drive Case

[+mytek]

I guess Mr. Hogan didn't get the message that bare boards will now be sold at The Brewing Academy .

 

 

[ivop]

On 8/18/2019 at 5:49 AM, mytek said:

Why MIDI?

People might question why I made MIDI so central to this system, but to me it's more than just about the music, although that will be very nice to have. The MIDI interface also gives us a very robust optically isolated network that can be expanded up to 16 computers or devices on a shared interconnected ring, that can reliably send and receive data up to 75 feet between hubs, with each hub acting as a repeater. Between this and the now very inexpensive stand-alone SIO2MIDI devices, our Atari's for the first time ever have the means to be networked for cheap, even crossing the boundary between 8-bit and ST. And all it'll take is applications to be written with this in mind, while MIDI-MAZE serves as a good example of how that could be done.

I'm forever grateful that you were inspired by my enthousiasm about MIDI and improved upon MIDI Muse and incorparated it into your new design, including the WaveBlaster port. Considering your 1088XEL boards, the WaveBlaster carrier board and the board with three MIDI ports, together they basically make the next MIDI Muse, so I see no need to create that next incarnation. People can just use your two boards, put them in an enclosure, connect the right SIO connections to a cable, a switch to select the connection to the WaveBlaster device, et voìla   A perfect stand-alone MIDI device with built-in synth.

 

 

[+Firedawg]

It begins.......

 

[+mytek]

2 hours ago, ivop said:

I'm forever grateful that you were inspired by my enthousiasm about MIDI and improved upon MIDI Muse and incorparated it into your new design, including the WaveBlaster port. Considering your 1088XEL boards, the WaveBlaster carrier board and the board with three MIDI ports, together they basically make the next MIDI Muse, so I see no need to create that next incarnation. People can just use your two boards, put them in an enclosure, connect the right SIO connections to a cable, a switch to select the connection to the WaveBlaster device, et voìla   A perfect stand-alone MIDI device with built-in synth.

Thanks for being my 'muse' when this project was first under development. At the time I was looking for things to make this 2nd motherboard creation unique and worth doing. Due to the extra space that was available in the 1050 case vs. a Mini-ITX case, I was able to leverage that and integrate things like the IDE and of course the MIDI circuit with the S2 synth board. Then one thing led to another, and MIDI began proliferating and merging with other projects. So here we are today with the ability to easily and cheaply add MIDI to any A8 based system. Pretty cool if you ask me .

 

Now we just need to see more games and applications created or modified to take advantage of it.

 

[AtariGeezer]

Bought two to start with

Edited August 20, 2019 by AtariGeezer

[+mytek]

Schematics and the firmware are downloadable at: https://ataribits.weebly.com/1088xld.html

 

Just scroll down to bottom of page.

 

[AtariGeezer]

got'em, thanks...

[+Stephen]

Here's some details on how I got my board properly fitted in the 1050 case, as well as some fine details on issues I had with the CF card reader:

 

I had to use a counter-sink bit to make this screw sit perfectly flat with the PCB, else the lower CF card would not insert.

 

Check that clearance Clarence:

 

Very important to screw the SIO plugs to the PCB.  I unfortunately had to use a #39 drillbit in order to get 6-32 screws through the PCB.

 

When it came time to put the 6-32 studs into the 1050 case, I decided to do it "proper" style (as a metal worker at heart).  Using a #28 drill, I then ran a 6-32 tap in the case.  I used a paper washer in between the case and nut which was adjusted for proper height.

 

Some hand files enlarged the drive select square for the 13-pin DIN for video.

 

Some final fitment details:

 

As always, full build thread is at https://www.flickr.com/photos/75619516@N06/albums/72157705660251381.  If you use any images, please credit me for the build.

 

 

[Dropcheck]

Awesome!

[+DrVenkman]

Nice pics and details, Stephen! I used some M3-sized nylon screws and nuts to secure the SIO ports in my XLD build. Those fit pretty much perfectly, though obviously not as objectively strong as a steel screw and nut. And of course, for anyone who goes with a single CF cart interface there're no need to countersink the mounting screw or anything of that nature.

 

 

[+mytek]

The original plan was to use either SST or zinc plated steel 4-40 screws and nuts for the SIO, then no drilling required . I don't really like those nylon ones all that much, since they feel a bit flimsy especially when tightening the nut.

 

Nice pics Stephen ? . Unit looks real nice, and I presume show ready at this point.

 

[Kyle22]

12 minutes ago, mytek said:

I don't really like those nylon ones all that much, since they feel a bit flimsy especially when tightening the nut.

 

Yes, and I believe they allow some movement, which can lead to 'XF-551 Syndrome" (broken traces under SIO connector).

I prefer metal bolts / machine screws WITH lockwashers. It can't move at all that way.

 

[+DrVenkman]

5 minutes ago, Kyle22 said:

 

Yes, and I believe they allow some movement ...

 

Maybe if you're shoving stuff in there like you're trying to break it.  

Plenty of A8 machines in the world made it out of their factories with no fasteners whatsoever or with little nylon pin-widgets.  It'll be fine in my own capable hands.  

[Kyle22]

1 minute ago, DrVenkman said:

Maybe if you're shoving stuff in there like you're trying to break it.  

Plenty of A8 machines in the world made it out of their factories with no fasteners whatsoever or with little nylon pin-widgets.  It'll be fine in my own capable hands.  

 

Fine. Save a few pennies and make your computer LESS than it could be. Your choice.

What happens when your kid gets hold of this? Kids are NOT gentle with hardware...

:)

 

[+DrVenkman]

4 minutes ago, Kyle22 said:

 

Fine. Save a few pennies and make your computer LESS than it could be. Your choice.

What happens when your kid gets hold of this? Kids are NOT gentle with hardware...

 

My youngest child is 21. No worries that she'll suddenly take up an interest in my new/old Atari machines at this point. And frankly, nylon fasteners and all, my XLD is already more computer than any of my three 1200XLs (all of which left the factory with nylon fasteners on the SIO ports), my 800XLs (two of which have nylon fasteners on the SIO ports) or my former 130XE (now relegated to a donor board; NO fasteners on the SIO ports).

 

I'm more concerned with a dead GTIA or ANTIC dying due to age than I am with a lifted traced on one of my machines due to some perceived vulnerability to SIO port abuse.

 

But hey, man. You do you! If you want to friction weld nuts onto solid steel bolts to affix those sumbitches in place, more power to you.  

 

 

[Kyle22]

All I am saying is: It is best practice to firmly secure the port.

 

In your case it may not be strictly necessary, but it IS cutting corners and risking future (un-necessary) damage to a FINE machine.

 

I don't know what else to say. WHY would ANYONE take this RISK that could be eliminated for a very CHEAP price and SHORT amount of time?

 

I have no clue.

 

[Remember, NEW Builders may be reading this. That's why it MUST be done correctly WITHOUT cutting corners.]

 

I'm done on this one. Everyone who reads this, please Think about this yourself. It's better to be SAFE than SORRY. Especially with Atari stuff.

 

Edit: The Optics on this are awful for [you] @DrVenkman. This makes you look exceptionally cheap, lazy and without respect for Atari.

 

Please explain.

Thanks.

 

 

 

Edited August 23, 2019 by Kyle22
improvement :)

[+DrVenkman]

15 minutes ago, Kyle22 said:

Edit: The Optics on this are awful for [you]. This makes you look exceptionally cheap, lazy and without respect for Atari.

Heh. Atari had no respect for Atari, by your rationale given the no doubt hundreds of thousands of machines that made it out of factories with fasteners just like the nylon fasteners on my 1200XLs and 800XLs.

 

But when you build your own XEL and XLD machines, you do them however you want. Heck, if you're really concerned, go nuts! Epoxy the SIO connector to the board; use 316L stainless pins and friction welded rings as nuts. Because if you think a steel fastener and lock washer won't back out, you're merely not exposing that connector to the right environments (*). No fastener is perfect and the perfect is the enemy of the good enough. In my use, and in my application, I'm satisfied with my build. If I take my box apart to install a SOPHIA or VBXE this fall as planned and find a backed off nut, I'll be shocked. But I'll also admit it and I'll come back and say so (read waaaaaaay back up in the guts of the XEL builder's thread and see my story about effing up an expensive U1MB board changing the headers because I didn't quite qrok the technique ... ). I admit it when I make an objective "mistake". But I don't accept subjective opinion as truth in any kind of engineering sense. 

 

(*) I once designed fittings, connectors and fasteners for manned spacecraft life support systems as my real life paying day job when I was a baby engineer  - no bullshit. Lock washers back off too. Stick to friction welding if you can get away with it; locking pins if not. There are real life milspecs, NASA specs and contractor specs on this stuff. 

[Brentarian]

I guess I'm cheap, lazy, and without respect for Atari as well.  I used nylon screws on both my 1088XEL and 1088XLD.  Oh, the horror!  

[Kyle22]

I know I said I was done, BUT: My MAIN point is that NEW builders are reading this, and we should use the BEST and most reliable build style.

That's all.

 

[+DrVenkman]

Here's a hint to the non-engineer: connector forces are ideally axial. A pin of the "correct" nominal, in-spec diameter will prevent any axial movement of the connector body. Wiggling the connector to insert or remove will impart some degree of off-axis forces and thus impose some bending moment on both the shell of the SIO connector and thus the PCB surface and the pins themselves. The forces on the PCB would be spread across the entire bottom surface of the connector, especially the rear, and any bending moments on the pins themselves - to the extent not constrained by the plastic shell of the connector housing - would be distributed across all 13 pins and through-holes. The forces necessary to physically lift traces off a PCB would have to be substantially off-nominal and entirely out of ordinary usage.

 

To help limit any such bending, connectors often have through-hole for fasteners or in the cases of some (DB-15 connectors I've used to build 5200 controllers, for example), metal tabs you can solder to the pads around the through holes. The fasteners can be any number of kinds - pins and cotters; steel or brass screws and washers; nylon screws and washers; whatever you want. But in any event, such fasteners - are entirely secondary. The great majority of the "safety" as such is provided by the pin body itself preventing axial movement of the connector. 

 

And with that, I'm done with this topic. You (the putative XEL or XLD builder reading this) are entitled to make your own engineering analysis and do as you wish.  

[_The Doctor__]

at the very least in my humble experience with such things... generally when using nylon, I use a fixative, compatible loc-tite like product to ensure the port/jack/socket does not move and the threaded nylon nut and screw does not loosen over time.

 

I understand where kyle22 is coming from, though the wording became very strong.

 

I think he wants to be very proud of Dr. V and based on how fastidious V has been in the past about many things, and was taken aback over this particular niggle. Knowing SIO ports have been reports many times over the years as having traces cracked or broken.

 

we do love our Atari stuff.

[+Stephen]

The only thing I will say about this, is - the 1088XLD board is thinner and more fragile than the 1088XEL.  Reason being, the XEL was designed to take downward force of a cart being inserted, while the cart port on the XLD was never really intended to be there.

 

The board felt weak to me, and also, I use what stock I have available to me most times.  The 6-32 nuts & bolts holding these very SIO connectors in place, were my grand fathers, from most likely the mid 60s.

 

Also - think of my post as if it were done by Phil Hartman's "Anal Retentive Chef".  I go a bit overboard in everything.  Tell you one thing though, threading the 6-32 post inserts for securing the IO boards - very much worth it.

[Kyle22]

Yes, Doc. You hit it on the head. We should be an example of perfection, not cheapness (like my 'employer' [Bank] is).

 

This thread is to educate people on the construction of these wonderful devices. Please DO IT RIGHT.

:)

 

[AtariGeezer]

On 4/2/2019 at 10:24 AM, mytek said:

There is now a very simple 1088XLD landing page on my website: https://ataribits.weebly.com/1088xld.html

 

In the near future, this will be the page to go to in order to get the latest project documentation. And pretty soon I hope to be uploading a full schematic and BOM which Dropcheck has been so kindly putting together.

 

The official source for the boards will be coming directly from The Brewing Academy once the beta testing is completed.

Is the BOM ready for downloading???

Edited August 23, 2019 by AtariGeezer

[Dropcheck]

1 hour ago, Kyle22 said:

 

Yes, and I believe they allow some movement, which can lead to 'XF-551 Syndrome" (broken traces under SIO connector).

I prefer metal bolts / machine screws WITH lockwashers. It can't move at all that way.

 

Those traces sometimes did break because of SIO connector movement, but just as often the problem was the one sided poor quality pcb used.  That's not the issue with these boards.