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1088XEL Atari ITX Motherboard DIY Builders Thread

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1 hour ago, rj1307 said:

I have a question about TKII.
Are pins 10, 11 and 12 of the PIC chip (START / SEL / OPT signals) in a high impedance state when the keyboard button is not pressed? Can I connect these signals safely to ground? I want to connect additional buttons to them.

Yes those I/O pins are automatically changed to inputs when not actively being used as console switch outputs, so in theory physical switches could be used in parallel just like what would be done when installing a TK-II in a stock Atari 8-bit computer. However on a stock A8 I usually recommend making the TK-II connections on the GTIA side of the inline resistors, since those resistors would also prevent the console switches from looking like a dead short to ground, thereby giving additional protection to the TK-II I/O lines. But those inline resistors don't exist on an XEL. However it would be a simple matter to add some 100-200 ohm resistors in series with your add-on switches for a bit of extra safety.

 

20 minutes ago, bfollowell said:

I think I've probably seen it mentioned somewhere on here, but can't seem to find it now. Is there some great cleaning liquid that is better than anything else for cleaning up flux, etc. after a soldering session? Is IA as good as anything else?

I just use a 50/50 solution of alcohol and acetone bought from the hardware store, but be sure to keep it off of the body of the combo S-video/RCA jack, since that plastic doesn't like acetone. Although everything else is fine with it. The other option is to use a solder with a 'no-clean' flux which doesn't require it to be removed. I used this on my last two 1088XLD builds and didn't bother cleaning the flux off at all. Still no issues even after more than a year.

 

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On 2/8/2020 at 9:14 AM, Filon said:

Thank you, Michael! You were absolutely right - it was faulty ANTIC. Now I have a smaller problem - system boots up just after plugging power cord on, switching on gives just more brightness and louder sound. It has to be a short circuit somewhere in power module. But I'm still happy to see boot screen and working system. 

Sorry I missed this one.

 

Sounds like an issue with the NPD6020 (Q1) P-Channel Power MOSFET switch being in linear mode until truly switched on. In other words its seeing a partial turn-on signal all the time, and only fully switches when the ON latch is activated (555 circuit). Could be leakage through the PN2222 (Q2) transistor, or the wrong transistor being used in its place (PN2907?), or perhaps it got installed backwards by mistake. If you have an extra PN2222, you might want to try replacing Q2 to see if that fixes the problem.

 

XEL_power.thumb.png.cca8af7739003f1d2167191bc7f41df2.png

 

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1 hour ago, bfollowell said:

I think I've probably seen it mentioned somewhere on here, but can't seem to find it now. Is there some great cleaning liquid that is better than anything else for cleaning up flux, etc. after a soldering session? Is IA as good as anything else?

 

Thanks.

 

I use no-clean flux and only rarely bother to clean up anything other than the worst spill or if I have to use a lot of it, and it makes a very unsightly glob. In that case 90%+ isopropyl and a nylon toothbrush takes it off easily with no damage to the components or board surface.

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@mytek, thank you for the information.
I have one more question, what is the PS2-AUX connector for? Can two keyboards be connected simultaneously?
Maybe I'll explain what I want to do ;) 
In my version 1088XEL I want to mount Gamecube Wavebird wireless controllers interfaces. One of them is also to support Start, Select and Option buttons, and I still want to use Space (Pause). The interface will be made on AVR, I can simulate the PS / 2 keyboard with it and send the Space code. Will it work?

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18 minutes ago, rj1307 said:

@mytek, thank you for the information.
I have one more question, what is the PS2-AUX connector for?

It was a last minute decision to break out the normally unused 2nd PS/2 keyboard connection for a possible internal mod. So either something that could communicate in PS/2 (???) or perhaps use the two extra PIC I/O lines for something like what was done on the 1088XLD to allow the keyboard to select which joystick port will be for the mouse, and also have a 'Swap Disk' command.

 

 

Quote

Can two keyboards be connected simultaneously?

Yes if you are using TK-II OS V2.3 or V2.4 then a 2nd PS/2 keyboard can be used at the same time. the signals for it are available on the PS/2 jack on the back, only requires a special 'Y' cable to break it out.   Note: the green jack will be for the 2nd keyboard, not a mouse

 

PS2_Y.jpg.6bb6e8b1d1113292921fe8915414a3ff.jpg

 

StarTech PS/2 Keyboard Mouse Splitter

 

 

Quote

Maybe I'll explain what I want to do ;) 
In my version 1088XEL I want to mount Gamecube Wavebird wireless controllers interfaces. One of them is also to support Start, Select and Option buttons, and I still want to use Space (Pause). The interface will be made on AVR, I can simulate the PS / 2 keyboard with it and send the Space code. Will it work?

If it speaks PS/2 then I don't see why it won't work. Sounds like a cool idea ;-) .

 

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It's a good news! The interface will be made as an internal module, so I can use the PS2-AUX connector, I have the v2.4 software loaded.

I plan to expand my 1088XEL with other interfaces, I have PCBs designed for most of them, details soon. ;) 

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2 hours ago, rj1307 said:

It's a good news! The interface will be made as an internal module, so I can use the PS2-AUX connector, I have the v2.4 software loaded.

I plan to expand my 1088XEL with other interfaces, I have PCBs designed for most of them, details soon. ;) 

Sounds very interesting, Please do share the details when you get a chance :) .

 

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It doesn't look like much so far, but after sitting on everything for most of a year, I've finally started on my 1088XEL build, and I'm super excited!

 

Working it in around lawn work, work, and other projects, it'll probably take me a while to finish it, but I figured I needed to start somewhere.

 

I'm using the suggested assembly procedure and checking off as I go.

 

Wish me luck!

 

 

IMG-3408.jpg

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Looking good! I hope I'll be able to say the same, but I know I'll get pulled off onto other things. It still feels good to be going on it though.

 

Good luck! Here's hoping she boots up on the first try!

 

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For those more in the know, I'm curious about the PAL setup. I didn't order the PAL crystal because I grew up on NTSC machines and that's what I want out of my XEL. If you install all of the NTSC and the PAL circuitry, can you switch between the two by simply moving that NTSC/PAL jumper on the motherboard?

 

It's been too long since I ordered all of my components and I can't remember if we had to choose which to make our machine and order accordingly, or if there were spots on the board to install both crystals and whatever else is required.

 

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To change between NTSC and PAL you need to
Note 1 NTSC ANTIC CO12296 or CO21697
Note2 NTSC GTIA CO14805
PAL ANTIC CO14887 or CO21698 PAL GTIA CO14889
 

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41 minutes ago, bfollowell said:

For those more in the know, I'm curious about the PAL setup. I didn't order the PAL crystal because I grew up on NTSC machines and that's what I want out of my XEL. If you install all of the NTSC and the PAL circuitry, can you switch between the two by simply moving that NTSC/PAL jumper on the motherboard?

 

It's been too long since I ordered all of my components and I can't remember if we had to choose which to make our machine and order accordingly, or if there were spots on the board to install both crystals and whatever else is required.

 

I am pretty sure you got it from us and you should have everything in there to make it PAL or NTSC except for the main crystal and the PAL Atari ICs (ANTIC & GTIA).  Everything else is the same.

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52 minutes ago, MacRorie said:

I am pretty sure you got it from us and you should have everything in there to make it PAL or NTSC except for the main crystal and the PAL Atari ICs (ANTIC & GTIA).  Everything else is the same.

Yes, I looked back again and saw that you had to choose which way you wanted to go and put the correct crystal in accordingly.

 

Now for another one. I must be blind as a dad-blamed bat! A few of these I've had to search the board over and over to find the correct location but, for the life of me, I can't find R53 anywhere on the board. The part ID says R53 (Vsync Mod). Would someone with more familiarity, or better eyesight, please tell me where that one goes?

 

Thanks!

 

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1 hour ago, bfollowell said:

Yes, I looked back again and saw that you had to choose which way you wanted to go and put the correct crystal in accordingly.

 

Now for another one. I must be blind as a dad-blamed bat! A few of these I've had to search the board over and over to find the correct location but, for the life of me, I can't find R53 anywhere on the board. The part ID says R53 (Vsync Mod). Would someone with more familiarity, or better eyesight, please tell me where that one goes?

 

Thanks!

 

R53 & C13 go underneath the board on the DIN13 part of the board. I am away from the shop atm, so I can’t send you a picture right now. Will do so as soon as I get a chance (unless someone beats me to it)

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8 minutes ago, MacRorie said:

R53 & C13 go underneath the board on the DIN13 part of the board. I am away from the shop atm, so I can’t send you a picture right now. Will do so as soon as I get a chance (unless someone beats me to it)

 

OK, that rang a bell. I kept thinking I'd seen something about a mod when used with an SC1224 monitor. I found this link just a bit ago.

 

I've sold off all of my SC1224 monitors and I only own LCDs. I'll be putting the UAV, a Sophia DVI, and a VBXE in my 1088XEL. Whenever I'm using the VBXE, I'll be using it with my OSSC using the Cool Novelties DIN13 SCART cable, so I'm not sure I would need this mod. What do you think? It looks easy enough to add if necessary. I'm just not sure that it will be in my case.

 

 

https://atariage.com/forums/topic/272817-1088xel-atari-itx-motherboard-diy-builders-thread/page/7/?tab=comments#comment-3928969

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It's going well. I'm surprised at how quickly it goes when you get on a roll.

 

I got all the resistors, diodes, and inductors installed, except for the 4 10K resistors that I somehow missed ordering, and all of the resistor networks and non-electrolytic capacitors are installed.

 

Next will come transistors, LEDs, and IC sockets. I'll probably have to take a break for a couple of days of lawn care and real work before I get to that point, but I figure that step will be a day's worth of playing.

 

There really won't be much left after that except the MosFET, crystal and headers and connectors. At this rate, I'll be done before my 10K resistors make it in.

 

I still have to assemble my XEL-CF3, mouse selector switch, and JOY2PIC-STIK PIC Chip Programmer, though, so I guess I have plenty to keep me busy.

 

 

IMG-3410.jpg

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Looking good 👍 .

 

Just be thankful that you are assembling this instead of an original 800XL. Although the XEL has more capabilities than a generic A8, it has probably somewhere around half as many individual discrete components to make that happen.

 

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Man! Talk about a round about way to get something done! I got my JOY2PIC Stick assembled and it was time to program my VGate, TK-II, and Mousetari PIC chips, only to find that my AtariMax SIO2PC-USB seems to have died. Steven is sending me a replacement, but that will take at least a few days. I looked into building a simple SIO2USB cable using an old, half-defective SIO cable I have and a FTDI USB to TTL Serial 5V Adapter, but that was going to be at least two or three days from Amazon, and I'm really impatient when I'm in the middle of a project.

 

The only thing I have to get software onto my 800XL from my PC right now is my Ultimate Cart and it I can't run atr images from it. Or can I? I seemed to remember that we could run atr images from an AtariMax MaxFlash cartridge. So, I rooted around the AtariMax site and finally found a download for the MaxFlash Studio software. I created a workbook that had all three PIC chip programming atrs on it, then exported it as a MaxFlash car file, which happen to be compatible with my Ultimate Cart. The car file seemed to work ok in Altirra, so I copied it over to my Ultimate Cart and plugged it into my 800XL.

 

Success! I was finally able to get my 3 PIC chips programmed!

 

I went ahead and ordered the FTDI USB to TTL Serial 5V Adapter cable from Amazon and I'm going to go ahead and put together a cheap SIO2USB cable, plus I'll have my AtariMax SIO2PC-USB once Steven gets a new one to me. I should be in pretty good shape from here on out. Everything just seemed to break down at a bad time.

Edited by bfollowell

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33 minutes ago, bfollowell said:

I looked into building a simple SIO2USB cable using an old, half-defective SIO cable I have and a FTDI USB to TTL Serial 5V Adapter, but that was going to be at least two or three days from Amazon, and I'm really impatient when I'm in the middle of a project.

 

In a pinch you can usually find an Arduino USB programming board for less than $10 at any local electronics supply shop.  That'll work as an SIO2PC adapter.  Here's a common example:

https://www.elliottelectronicsupply.com/arduino-accessory-xbee-usb-adapter-bluetooth-ft232rl-usb-to-serial-port-module-for-pc-arduino-d.html

 

 

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Yeah, with the demise of Radio Shack, a lot of towns no longer have any local electronics supply shops. There could be one somewhere in my town, but I'm certainly not aware of one is there is. Hence my Amazon order. I'll look into it though. I'm good for now, but it may come in handy in the future.

 

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3 minutes ago, bfollowell said:

Yeah, with the demise of Radio Shack, a lot of towns no longer have any local electronics supply shops. There could be one somewhere in my town, but I'm certainly not aware of one is there is. Hence my Amazon order. I'll look into it though. I'm good for now, but it may come in handy in the future.

 

Oh, I know!  We're down to that one shop I linked to for that kind of thing.  I hope there's enough local business for that place to stay open indefinitely.  😥

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OK, so, I was all excited. I haven't assembled into the case yet, but the board is done, so I decided to fire it up. I was sooooo certain I'd done everything perfectly and that it would fire up the first try. Alas, it was not meant to be. First of all, I forgot the NTSC/PAL & the J20 stock video jumpers. I added those. There's a third jumper, but it has something to do with the SIO2PC module's handshaking, so I don't think it's required at the moment, so I'm using it as a switch to short out the power switch contacts.

 

So, now it appears to be doing something, but I'm still not getting anything but a black screen. I have 5V & On LEDs both on. The only video output I have at the moment, until my replacement UAV arrives in a few days is Sophia DVI. I'll explain the whole replacement UAV story in a later post. The TV picks up at least part of a signal because it comes up and says 1280x1024 60Hz, which is the resolution that I have my Sophia programmed for. Actually, I think I may have just answered my own question. If I don't have a VBXE, I have to have the UAV installed to get any video at all out of it, correct? Even if I have a Sophia DVI installed? If so, then that's why I'm not getting anything but a black screen. If someone could confirm that for me, I'd really appreciate it. If that's the case, my UAV is supposed to be in Saturday and I'll try it again then.

 

Thanks.

 

 

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The 1088XEL with a Sophia DVI board installed does not require any other video board to be present in order to produce video from the DVI output. However you do need the appropriate NTSC or PAL GTIA plugged into the Sophia.

 

Minimally for NTSC operation you need a 3.579 Mhz crystal for X1, the OSC header (J20) needs to be jumpered. The VGATE chip is not needed, since that feature is built-in to the Sophia (however the VGATE chip does need to be there for the UAV). The PAL/NTSC jumper on header J21 is a no care with the Sophia.

 

PAL requires a 3.546 Mhz crystal for X1, and a 4.433 Mhx crystal for X2 and a 74HCT74 plugged into the U20 socket. Of course you'll need a PAL version Antic and GTIA chip as well.

 

Hook up an amplified speaker or plug in a set of headphones and see if you hear the Basic farting noise following start-up and key clicks when pressing keys on the keyboard. If you don't hear at least one of these sounds, then the problem may not be related to your video circuits at all.

 

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