1088XEL Atari ITX Motherboard DIY Builders Thread

[+DrVenkman]

 

Looks like version 1 of the U1MB cpld firmware...... ?

 

That's still Lotharek's default firmware for all U1MB's. Even one I bought just a couple months back for one of my 1200XL's still came with it. First thing I do once I get a machine up and running is flash Jon's latest and greatest.

 

Speaking of which, I've got Jon's most recently-posted 1088XEL U1MB firmware flashed to the virtual U1MB in Altirra and it works great. It'll be a couple weeks until I get my board built up enough to try it on the real thing, probably.

[+LarryL]

 

Looks like version 1 of the U1MB cpld firmware...... ?

 

yep - it is like I got it from Lotharek

 

I am still a complete newbie on Atari 8bit - used to work with STs

So I have to learn everything from scratch ...

 

Thought it would be kind of cool not to start with an exiting XL or XE, but build my own one

Although I own a few XL and XE (I collect such stuff) but never did anything with them except powering them up

 

So next (besides finishing HW) would be learning how to transfer files to the XEL by using the SIO2PC in order to flash the U1MB

 

regards

Michael

[+DrVenkman]

 

So next (besides finishing HW) would be learning how to transfer files to the XEL by using the SIO2PC in order to flash the U1MB

 

regards

Michael

 

Easy-peasy. If you haven't already got some SIO emulation software on your computer, download and install RespeQt (see stickied thread at the top of the 8-bit forum here), connect a USB cable between the 1088XEL and your computer. RespeQt should recognize the adapter. If it doesn't, you can select it in the RespeQt options screen. Download Jon's firmware work-in-progress posted a page or two back in this thread and unzip the files. Put that "firmware.atr" file in the Disk 1 slot, boot your 1088XEL to SpartaDOS X. Then at the D1: prompt type (without the quotes) "X UFLASH.XEX"

 

Uflash will load and hopefully recognize your U1MB. Select the "Firmware" slot on the screen with the arrow screens, press ENTER and you should be prompted to select a firmware file from the .atr image you've got mounted in the D1: slot in RespeQt. Select the "FIRMWARE.ROM" file to flash, let UFLASH read, write and confirm the file and you should be good to go. Reboot and you're updated.

[+mytek]

I have a Protek 20MHz Oscilloscope. I'm not as proficient as I need to be so some instruction maybe required .

 

scope.jpg

 

You would hook a x10 probe up to the OSC header, and grab the ground from the board mounting hole in the corner. Adjust the Vertical VOLTS/DIV to 100mv, and then start turning Horizontal TIME/DIV until the actually waveform can be seen. To lock in the signal, adjust the Trigger Level adjustment pot. For NTSC 3.57Mhz you should see something similar to this.

 

 

 

That's still Lotharek's default firmware for all U1MB's. Even one I bought just a couple months back for one of my 1200XL's still came with it. First thing I do once I get a machine up and running is flash Jon's latest and greatest.

 

Speaking of which, I've got Jon's most recently-posted 1088XEL U1MB firmware flashed to the virtual U1MB in Altirra and it works great. It'll be a couple weeks until I get my board built up enough to try it on the real thing, probably.

 

I think there might be a problem with the latest BETA release that Jon posted over on the main 1088XEL thread where NTSC is concerned. You might want to hold off for a bit until that gets resolved. What it does is sometimes prevents proper boot-up after Antic has warmed up.

 

- Michael

[+Firedawg]

You would hook a x10 probe up to the OSC header, and grab the ground from the board mounting hole in the corner. Adjust the Vertical VOLTS/DIV to 100mv, and then start turning Horizontal TIME/DIV until the actually waveform can be seen. To lock in the signal, adjust the Trigger Level adjustment pot. For NTSC 3.57Mhz you should see something similar to this.

 

3.57Mhz_OSC.png

 

Thanks Michael. When I get home later this evening I'll hook it up I see what we find.

 

Mike

[+LarryL]

 

Easy-peasy. If you haven't already got some SIO emulation software on your computer, ownload and install RespeQt (see stickied thread at the top of the 8-bit forum here), connect a USB cable between the 1088XEL and your computer. RespeQt should recognize the adapter. If it doesn't, you can select it in the RespeQt options screen. Download Jon's firmware work-in-progress posted a page or two back in this thread and unzip the files. Put that "firmware.atr" file in the Disk 1 slot, boot your 1088XEL to SpartaDOS X. Then at the D1: prompt type (without the quotes) "X UFLASH.XEX"

 

Uflash will load and hopefully recognize your U1MB. Select the "Firmware" slot on the screen with the arrow screens, press ENTER and you should be prompted to select a firmware file from the .atr image you've got mounted in the D1: slot in RespeQt. Select the "FIRMWARE.ROM" file to flash, let UFLASH read, write and confirm the file and you should be good to go. Reboot and you're updated.

Thanks DrVenkman,

This guideline speeds things up a lot :-)

That’s how it looks now

 

Amazing

[+DrVenkman]

So quick question -

 

Are the DIL resistor networks socketed? I have a slew of various-sized sockets and other than generally glancing over them, I haven't actually counted them all and associated them all with a specific chip or board location. I'm installing resistor networks this afternoon and realized I haven't actually seen in any of the pics or videos if those DIL units are socketed. I can't really see the reason they would be and I don't think the BOM shows them to be, but out of an abundance of caution, before I do anything that'd be a pain the rear to fix, it would be nice to have some confirmation.

​Thanks.

[+LarryL]

I did not put the resistor networks into sockets, soldered them directly.

The BOM also did not contain any sockets for them.

I also do not think that such resistors are in danger to fail

[Brentarian]

Correct, no sockets for the resistor networks. Also make sure they are oriented correctly.

[Marius]

Do I really miss an XEGS keyboard connector on the PCB?

 

I am really interested in this project, but am I right that I have to use a PC keyboard? I think that is something to improve in the next revision of this project.

 

I am not a huge fan of the XEGS keyboard, but one could install another XE keyboard in that case.

Perhaps these cases can be created using a 3D printer...

[+DrVenkman]

Thanks guys. I flipped through Jon’s videos again and found where he installed them without sockets so I went ahead.

Another day, more melting bits. Installed the diodes I had forgotten about yesterday, along with all the resistor networks, and inductors. It's a blast to watch the board fill in day by day.

 

 

I'll get started on the rest of the ceramic caps tomorrow after work, probably, unless I take a night off to work on my LEGO Saturn V. My son and I spent about 2-1/2 hours building the first stage the other night but haven't had time to get back to it.

 

[+orpheuswaking]

Looks like the 1088xel and LEGO Saturn V are a natural combination

 

[+mytek]

Do I really miss an XEGS keyboard connector on the PCB?

 

I am really interested in this project, but am I right that I have to use a PC keyboard? I think that is something to improve in the next revision of this project.

 

I am not a huge fan of the XEGS keyboard, but one could install another XE keyboard in that case.

 

Yes a PS/2 keyboard is a must. But there is an option for a more Atari like experience. If you do a CTRL+ALT+F4 combo and step through the 4 possible key maps, the 4th selection is for an A8 mapping of an ISO keyboard. BTW, a selection can be verified by pressing ALT+F4 which will print the present selection to the screen. And lastly whatever key map has been selected will be forever retained in EEPROM so that it will always come up in the desired configuration. Anyway the only other requirement is to re-lable a few keys either with stickers or better yet have some custom key caps made. Check out the key maps here: http://ataribits.weebly.com/device-compatibility.html

 

The end result will in most cases be a keyboard that is far superior to many of the later A8 keyboards, and if you chose a PS/2 keyboard with Cherry key switches, then even the best A8 keyboard ever made (the 1200XL) can be surpassed.

 

The other benefit of going with a detachable keyboard, is that you have freedom to move it around your desk or to your lap without having to drag a bunch of cords with you (SIO, joysticks, power and video connections). In fact even though it's not as prolific as USB, there are some wireless PS/2 keyboards that will allow you to completely cut the cord.

[+mytek]

Correct, no sockets for the resistor networks. Also make sure they are oriented correctly.

What's nice about the dip versions I've got specified, is that you could put them in rotated 180 degrees and they would still work just fine. Only the SIP resistors, and only the ones that are bussed need to be installed with pin 1 in the proper location (square pad with square designation in silk screen). Of course to avoid confusion, it's best to install all of the resistor networks in the proper pin 1 orientation .

[Marius]

But I am pretty sure you can not reach the same compatibility with a non Atari keyboard. This is same as with emulation. Is the keyboard fully operational when the 1088XEL is powered? I guess that the interface is not instantly active.

 

I would prefer at least the option to attach a real Atari keyboard in stead of this. The strength of this project is that a new Atari is created with real chips instead of emulation. A ps/2 keyboard will probably give a better typing experience but that does not mean it gives a real Atari experience.

[Marius]

Clarification: I meant the external XEGS keyboard. It would be a good idea to add the connector to be able to hook up a real Atari keyboard.

[+DrVenkman]

Clarification: I meant the external XEGS keyboard. It would be a good idea to add the connector to be able to hook up a real Atari keyboard.

Well, the basic design is done. Michael achieved his goals and then some. But the board design files and such are all freely available. I’m sure he’d encourage you to go grab them and modify them as you wish to add or remove whatever you like.

[+mytek]

But I am pretty sure you can not reach the same compatibility with a non Atari keyboard. This is same as with emulation. Is the keyboard fully operational when the 1088XEL is powered? I guess that the interface is not instantly active.

I would prefer at least the option to attach a real Atari keyboard in stead of this. The strength of this project is that a new Atari is created with real chips instead of emulation. A ps/2 keyboard will probably give a better typing experience but that does not mean it gives a real Atari experience.

Although the PS/2 keyboard isn't instantly ready to roll on power-up, this has been compensated for by the 1088XEL version of the U1MB BIOS that Jon is working on. So in other words things like holding Start, Select, or Option are still recognized and acted upon the same as a stock A8 keyboard. However I won't lie and tell you it's 100% the same as stock in all regards, but for the most part these small differences wherever they do exist will make minimal impact on the Atari experience. And to compensate for any short comings, it also has areas where it is better than stock as in additional features (i.e., one key navigation via the separate arrow keys). Also due to the 3 key (or more) roll-over ability of the PS/2 keyboards, as well as a built-in key buffer, there will be fewer missed keystrokes in all cases. And the missing CTRL+SHIFT key combinations that plague the stock A8 keyboard are present with the PS/2 keyboard. And there is even more... recordable macros, a built-in word processing like auto insert and back space rub-out capability, fast cursor movement, ect..

 

But true to your statement of it being emulated, it'll never be considered the same by purist such as yourself.

 

It was suggested early on that I should provide a stock keyboard interface, but I chose not to time and time again. This was my prerogative, and since I was not trying to create a drop-in replacement motherboard, it seemed like a good way to go, and I still feel the same to this day. After all if you wanted stock, then by all means buy a stock system. People keep talking about a replacement for their aging machines, but the truth is, it isn't the motherboard that is the problem, but in reality the aging over worked chips that become the issue.

 

But if a person really insists on using a stock keyboard on the 1088XEL I'm not going to stop them, and they are always free to add in a Pokey piggyback board to do so. But what is the point, because other than the worse keyboard ever (the XEGS), there is nothing that will simply plug in and be truly usable on a Mini-ITX platform (what about the case?). Also since my designs are free to all, and there are presently two alternative versions in the works by ivop and dropcheck that are open source, someone else can always recreate what I've done in a more Atari like form as has been suggested. My offering in this arena is done as far as I'm concerned, and it is what it is.

[flashjazzcat]

Judging by the tests I'm currently performing with my 1088XEL set up as an NTSC machine, the keyboard takes c. 3 seconds to initialise following a cold power-up. As Michael points out, the 1088XEL build of the U1MB BIOS compensates for this to some extent by displaying a mandatory boot logo when the board is powered up. The logo (and the delay) isn't present during forced reboots, etc, and is quite separate from the "Splash screen" which one may optionally enable. However, the mandatory boot logo is currently only displayed for a couple of seconds, so it's still recommended to leave the splash screen enabled too (the boot logo segues seamlessly into the splash screen with progress bar). As things stand, if you turn off the splash screen, the keyboard still isn't ready after the boot logo has disappeared, and keys (Help, Option, etc) held on cold power-up will be ignored.

 

One approach I'm experimenting with is to simply prolong the cold boot logo to three seconds. This allows held keys at power-on to be recognised even with the splash screen disabled. This might make more sense, since strictly speaking the keyboard should become responsive as soon as the splash screen tells you to press Help for setup, etc. Of course we'll decide on a compromise which suits everyone.

[flashjazzcat]

Found and fixed a bug in the 1088XEL build of the main BIOS which occasionally caused a hang on power-up, mainly on NTSC machines when the SRAM hadn't had time to fully clear after a power-down. Not a bricking scenario by any means, but those wishing to update to the latest firmware might want to wait until I post the update (probably after Michael tests it on his system). Seems to be working great here.

[+Firedawg]

 

You would hook a x10 probe up to the OSC header, and grab the ground from the board mounting hole in the corner. Adjust the Vertical VOLTS/DIV to 100mv, and then start turning Horizontal TIME/DIV until the actually waveform can be seen. To lock in the signal, adjust the Trigger Level adjustment pot. For NTSC 3.57Mhz you should see something similar to this.

 

3.57Mhz_OSC.png

 

- Michael

 

Finally got sometime today to get some work done! Hopefully everybody had a great New Year Celebration!!! Michael, I have below my results of my scope. Please let me know if my contact points are wrong or my settings on my scope are in-corrected. Now that I have my house back to myself I put my full attention to getting this board working!!!! I'm glad to see that others are seeing their boards working with some adjustments, as this is giving me some very much needed encouragement.

 

 

[+mytek]

Mike your oscillator looks to be working fine. You should be able to pick up that same signal on GTIA pin-28 and V-Gate pin-2 (you might want to verify that). And as a further check, you should see half that frequency at pin-37 on the CPU. Also check CPU pin-40 to see if it's high (+5V). It should only go low for about a 1/4 of second on power-up, or when pressing the F8 key.

 

If all those things look good, then there is a slim possibility that the Last U1MB BIOS download might be influencing this (there's a new one on way that will fix that issue). Although if I recall correctly you also were not seeing video prior to updating the BIOS in your U1MB, so that's probably a non-issue.

[flashjazzcat]

Here's the aforementioned update:

 

1088XEL_U1MB_Firmware_beta_020117.atr

 

Flash FIRMWARE.ROM to the firmware slot as usual.

 

I don't know if folks have had time to do much testing (with both PAL and NTSC boards) using the prior update, but the absence of bug reports aside from the issue Michael spotted suggests to me that it's safe to turn attention to finalising and releasing the standard U1MB and Incognito versions of this update.

Edited January 2, 2018 by flashjazzcat

[+DrVenkman]

Whew!l Last 30 ceramic caps on the board. These last, as provided in my kit, were 0.1 uF disc caps, in the same style as the others supplied, rather than the axial style most of the beta testers used, I guess. The only thing is, these caps were not made with the little "dog leg" double 90 degree bend to fit the hole spacing. As a result, I had to try to carefully center each one as low as I could make it on the board before soldering in place. Unfortunately, a couple of them ended a bit lopsided from what I intended. Won't affect functionality of course but it does annoy me a bit. Ah, well. I understand many artists work an intentional flaw into their artwork as a "calling card" of sorts - I'm gonna go with that explanation if someone ever mentions it in years to come.

 

[+DrVenkman]

Here's the aforementioned update:

 

1088XEL_U1MB_Firmware_beta_020117.atr

 

 

I think you need to change the year of your next filename Jon.

 

(Happy New Year, by the way!)