1088XEL Alternative Mother-Board Project

[rockdoc2010]

The U1MB has three male headers. Once you replace the two large ones on either end, they all point up off the board. The 1088XEL has three matching female headers for those same pins.

 

The three IC sockets on the on 1088XEL underneath the U1MB mounting space are for PIA and two of the PIC chips as I recall (it’s been 8 months since I finished building mine - look at the pics in my earlier post; I *did* build one and I use it nearly every day so I kinda know what I’m talking about at least a little bit [emoji14] )

 

yes i have just removed the smaller one and lost three pads in the process. I know what i am doing as well at 14years old i aced a class in electronics assembly.. but the square peg that went into that round hole is SO tight that it is bound to happen.

lets hope i can save the U1MB

 

Douglas

[rockdoc2010]

Slow down, take a deep breath and look at the first photo in my first reply to you. That shows all three female headers that everything on the upside-down U1MB plugs into. I built mine myself and use it every day so I’m not blowing smoke here.

 

I get this.. no worries BUT the 2x5 in the XEL dont match up to the 5x4x2 headers on the U1MB.

 

they do with the 5 and the 4 where did the 2 pin header go?

 

Douglas

[+mytek]

The 2 pin header you keep referring to is for configuration of the U1MB to tell it to be an XEGS. This is where you would place a shorting jumper if you wished to have it boot up as such. Since it is not needed to connect to anything on the 1088 motherboard, that is the reason there is no female header to mate with it.

 

As you have learned the hard way. Knowing how to solder something, is not the same as knowing how to properly de-solder components from an already assembled PCB, which is much, much harder. This is an acquired skill that requires considerable practice and patience to master. It also requires knowing the proper technique, such as cutting apart a multi pin header into individual parts prior to the attempt to de-solder it from the board.

 

I am sorry you are having so many problems with modifying your U1MB.

[rockdoc2010]

The 2 pin header you keep referring to is for configuration of the U1MB to tell it to be an XEGS. This is where you would place a shorting jumper if you wished to have it boot up as such. Since it is not needed to connect to anything on the 1088 motherboard, that is the reason there is no female header to mate with it.

 

As you have learned the hard way. Knowing how to solder something, is not the same as knowing how to properly de-solder components from an already assembled PCB, which is much, much harder. This is an acquired skill that requires considerable practice and patience to master. It also requires knowing the proper technique, such as cutting apart a multi pin header into individual parts prior to the attempt to de-solder it from the board.

 

I am sorry you are having so many problems with modifying your U1MB.

thank you for the clarification.. the lost pads will be dealt with i hope at the source i have cash but 70$ for a header issue chaps my hide!

 

Once again i bow to this build. not you but all of the guys involved have made my day! i can solder and i understand a bit but i do bow to those that make the ATARI live beyond its years,, If i could get you all together in one place I would buy you all a very expensive shot of scotch!

and then i would ask if you had any spare parts...

[rockdoc2010]

The 2 pin header you keep referring to is for configuration of the U1MB to tell it to be an XEGS. This is where you would place a shorting jumper if you wished to have it boot up as such. Since it is not needed to connect to anything on the 1088 motherboard, that is the reason there is no female header to mate with it.

 

As you have learned the hard way. Knowing how to solder something, is not the same as knowing how to properly de-solder components from an already assembled PCB, which is much, much harder. This is an acquired skill that requires considerable practice and patience to master. It also requires knowing the proper technique, such as cutting apart a multi pin header into individual parts prior to the attempt to de-solder it from the board.

 

I am sorry you are having so many problems with modifying your U1MB.

 

 

well i have done that. i take them out one pin at at time and stop after four or five.

i come back later.. frame of mind or the what not

Yes desoldering means destroying a board if not done correctly.

I hope it lives till the morrow

[+mytek]

Let this serve as a fair warning to anyone else that may be contemplating the header modification on a U1MB. Bottom line if you don't have prior experience with reworking a PCB, learning to do so on this board would not be suggested due to the high cost of failure. Instead if you decide that you really want to attempt this yourself, I would strongly suggest you practice and perfect this skill on something of little or no value, such as an already broken piece of electronic gear. Better yet if you have doubts, then enlist the services of someone that already has the prerequisite skills to do it for you.

[+Stephen]

 

dont try to desolder yourself.. i lost three pads and that was on the smaller header.

 

Douglas

I've done multiple of these for myself and others. Didn't even put a mark on the white PCB top or bottom. I wouldn't offer to do these if I couldn't do what is pictured below.

 

[+mytek]

I've done multiple of these for myself and others. Didn't even put a mark on the white PCB top or bottom.

Stephen I know at one time you offered to do this service for others, is that offer still on the table?

 

And if so, what compensation is required for doing so?

[+Firedawg]

As stated earlier (from others who have converted their U1MB boards) the component leads must be clipped for reasons that you do not want the temp of the iron reduced at the component by heat transferring to non-essential leads robbing the heat a way from the solder joint. Re-introducing fresh solder gives the location to be de-soldered some much needed flux to aid in removing the component. Issues with solder pads lifting are a result of 1). soldering iron on the component for too long 2). too much heat directly in contact on pad 3). attempting to remove component before solder is heated properly. A little knowledge, patience, and practice are the keys to de-soldering any type of component.

 

Mike

[+DrVenkman]

As stated earlier (from others who have converted their U1MB boards) the component leads must be clipped for reasons that you do not want the temp of the iron reduced at the component by heat transferring to non-essential leads robbing the heat a way from the solder joint. Re-introducing fresh solder gives the location to be de-soldered some much needed flux to aid in removing the component. Issues with solder pads lifting are a result of 1). soldering iron on the component for too long 2). too much heat directly in contact on pad 3). attempting to remove component before solder is heated properly. A little knowledge, patience, and practice are the keys to de-soldering any type of component.

 

Mike

Indeed. I had successfully desoldered parts before without issue (I replaced three sockets on one of my 1200XL’s without a problem) but removing these headers poses its own challenges - smaller parts and vias, more fragile board, lead-free solder ...). I did in fact ruin a U1MB doing the first set of pins the first time (see my posts in this thread from back in January-ish).

 

But then I made myself practice on the second header of the already damaged board until I had the technique down. The second U1MB went perfectly and completely trouble free. Damn shame I ruined a board but sometimes that’s how we learn valuable lessons.

[flashjazzcat]

Get some decent tacky flux (Amtech NC-559, for example) as well. That can make the difference between destroying vias and watching them magically clear with the lightest touch of the iron.

[rockdoc2010]

anyway it doesn't matter Lotherek is gonna send me one with straight headers. yes i will pay but then i have two of them.

 

Douglas

[rockdoc2010]

anyway it doesn't matter Lotherek is gonna send me one with straight headers. yes i will pay but then i have two of them.

 

Douglas

 

BTW i know how to desolder stuff.

[flashjazzcat]

Well: even the best of us never stop improving, and as said already, it's perfectly possible to remove the Lotharek headers without incident on a consistent and repeatable basis using the correct technique. If pads were 'bound to' come off no matter what, I would have wrecked about a dozen boards by now.

[+MacRorie]

Stephen I know at one time you offered to do this service for others, is that offer still on the table?

 

And if so, what compensation is required for doing so?

Just as a head's up: I also do this for folks as well. I have U1M on hand. $110 includes the U1M & the header change. $40 if you already have the U1M.

[+MacRorie]

This is a mute point! there are no UAV's available so I am currently building a brick

IF Bryan is out of UAV Rev D, I have a few for sale. Also, even without a UAV, you can get video out of the 1088XEL, but you need *some* kind of video board: A Sophia or a VBXE or a UAV. And, yes, I have all three.

[+mytek]

Just as a head's up: I also do this for folks as well. I have U1M on hand. $110 includes the U1M & the header change. $40 if you already have the U1M.

 

Nice of you to do this, and I would highly suggest that people take this route instead of DIY if they have any doubts as to their ability to do so. But it'll be nice if and when Lotharek sells them this way from the get go.

 

 

IF Bryan is out of UAV Rev D, I have a few for sale. Also, even without a UAV, you can get video out of the 1088XEL, but you need *some* kind of video board: A Sophia or a VBXE or a UAV. And, yes, I have all three.

 

Cool! Very nice of Bryan to let you do that .

 

----------------------

 

Ok now for an update on the MIDI-XEL board. I have reworked the layout a bit to better accommodate even low ceiling cases.

 

 

After I get some manufactured for testing, I plan on posting all the files on my website, including a few JOY2PIC flash ready versions of firmware (no intro, and possibly 2 or 3 with intro music). Of course I'll also upload the source code (written in Great Cow Basic) as well.

 

Everything provided will be open source, and can be integrated into other projects. Great Cow Basic is also open source and FREE so there should be no obstacles for customization to suit whatever people can dream up. I would also like to thank Ivop for his inspiration and initial designs that made this all possible.

[+MacRorie]

Nice of you to do this, and I would highly suggest that people take this route instead of DIY if they have any doubts as to their ability to do so. But it'll be nice if and when Lotharek sells them this way from the get go.

 

 

 

Cool! Very nice of Bryan to let you do that .

Well, these are just ones I purchased from him that I have not used.

[gozar]

Ok now for an update on the MIDI-XEL board. I have reworked the layout a bit to better accommodate even low ceiling cases.

 

MIDI-XEL_V1_1_PCB.png

 

After I get some manufactured for testing, I plan on posting all the files on my website, including a few JOY2PIC flash ready versions of firmware (no intro, and possibly 2 or 3 with intro music). Of course I'll also upload the source code (written in Great Cow Basic) as well.

 

Everything provided will be open source, and can be integrated into other projects. Great Cow Basic is also open source and FREE so there should be no obstacles for customization to suit whatever people can dream up. I would also like to thank Ivop for his inspiration and initial designs that made this all possible.

 

What about us non-1088XEL users? Can we hang this off of the regular SIO port?

[+mytek]

What about us non-1088XEL users? Can we hang this off of the regular SIO port?

 

Yes you sure can .

 

Basically it would be no different then installing a SIO2SD. Instead of using the right angle female header for P1, just use a standard vertical male pin header with a mating Dupont style plug and wires on one end, and soldered on the SIO side. This would also apply for a 1088XEL where something installed on the rear bezel is blocking a vertical mount situation, only in that case you would use a Dupont connector on both ends of the interconnecting wiring.

 

Edit: Well it would be a little different than an SIO2SD, having two more connections to make (Motor-ON and Clock-In).

[rockdoc2010]

 

Lotherak's U1MB Upgrade

 

Douglas

 

[+mytek]

Is that how he plans on selling the U1MB from this point forward, or is that just a special order item?

 

Opps, I do see a potential problem. Inclusion of the JTAG connector might get a bit too tight clearance wise above the 6520 PIA chip. I seem to recall someone mentioning that when trying to use one of the original black U1MB boards that Candle sold. Not sure if it's really an issue, but something that really should get verified. If it is a problem, then Lotharek needs to know. Kind of odd that he installed it, since all of his previously sold boards left it off the assembly.

[rockdoc2010]

I dunno.. But he is selling this one now for 64$ USD I do believe.

It is called the U1MB Upgrade.

 

Douglas

[+mytek]

I dunno.. But he is selling this one now for 64$ USD I do believe.

It is called the U1MB Upgrade.

 

Douglas

 

Based on what you said I went over to Lotharek's Ultimate 1MB Upgrade page, scrolled down towards the bottom, and found the same pic you posted. I just took a snap shot, and included the Disclaimer text he had written above it.

 

 

So apparently the transition over to straight headers has now officially happened.

 

However I do have concerns about the JTAG connector shown as included also in the picture. As I stated earlier, this could be a potential clearance problem above the 6520 PIA on the 1088XEL (as yet to be verified -- could be a non-issue).

 

Thanks for the heads up Douglas .

[flashjazzcat]

So apparently the transition over to straight headers has now officially happened.

Lord be praised.

 

However I do have concerns about the JTAG connector shown as included also in the picture. As I stated earlier, this could be a potential clearance problem above the 6520 PIA on the 1088XEL (as yet to be verified -- could be a non-issue).

It seems to be a non-issue. I had to check my 1088XEL, but sure enough the U1MB has the JTAG soldered in and there's no clearance issue that I can see.

 

This is excellent news, anyway.