1088XEL Atari ITX Motherboard DIY Builders Thread

[bfollowell]

Has anyone tried using a PS2 to USB adapter and a USB keyboard and/or mouse with their 1088? I was just curious if anyone knew whether or not that works.

 

 Thanks.

 

[StickJock]

I'm pretty sure that those are one-way, PS/2-->USB converters.  They are a simple USB HID device with a PS/2 host.  I have more recent experience with mice rather than keyboards, but I suspect that they use a cheap USB chip and then they bit-bang the PS/2 side.  The packets for mice are very similar.

 

To convert the other direction, it would take a lot more work.  You would have to be a PS/2 device with a USB host.

 

Just look at the connectors.  Is it a PS/2 socket with a USB plug (converting PS/2 to USB) or is it a USB socket with a PS/2 plug (converting USB to PS/2)?

 

 

[+mytek]

If they look like this...

Then you have a passive device that is really nothing more than a wired adapter (no active components inside).

 

These basically just rewired the connections from the USB side over to the PS/2 side, and in the early days of USB it would work. Essentially those early USB devices had a dual protocol chip inside that could sense and work with either USB or PS/2. Unfortunately the industry shifted away from that, and eliminated the PS/2 compatibility. Seems pretty silly to me when you consider that several companies had already perfected the dual protocol firmware, so you really weren't looking at any cost savings by eliminating those routines which were nothing but flashed software.

 

I'm not aware of anything that still supports the dual protocol any more.

 

[bfollowell]

Ok, so even if you had the device, a USB keyboard or mouse wouldn’t work with an XEL unless it was a dual protocol device?

 

Thanks.

 

[+mytek]

2 hours ago, bfollowell said:

Ok, so even if you had the device, a USB keyboard or mouse wouldn’t work with an XEL unless it was a dual protocol device?

That is correct .

 

[bfollowell]

I'm hopeful that International shipping may start back up soon and I may get my VBXE in. I'm curious about this note on the video schematic in reference to jumper 20. It says that the jumper is required for stock video, which I have in place currently, and to remove it for VBXE and connect VBXE to pin 2. But what if I still want my stock UAV output available for some applications?

 

 

[flashjazzcat]

1 hour ago, bfollowell said:

It says that the jumper is required for stock video, which I have in place currently, and to remove it for VBXE and connect VBXE to pin 2. But what if I still want my stock UAV output available for some applications?

That should still be fine. I think the jumper just allows the VBXE to provide the master system clock. UAV will still work.

[bfollowell]

I'm not sure about the UAV composite output of my 1088XEL. Or rather, I am sure that it doesn't look good. What I'm not sure about is the reason.

 

I've attached three images below of UAV composite output, and three images of the same screens from my Sophia DVI output. Obviously, my Sophia out put is going to look much better than my composite output, but the composite output doesn't look anywhere near as good as I feel it should from the videos and images I've seen online. And then there's the colors. I get this medium gray screen at the SpartaDOS X screen, rather than the nice blue screen that I should be getting. All the text seems to have a multicolored, artifacted thing going on. There's that weird almost iridescent blue line going down the left-hand side of the screen on the composite SpartaDOS screen. Honestly, the composite output of my stock 800XL looks much better, and we all know how bad that is!

 

Because of other issues that I've been having, I've went over most of the board several times in different ways, especially the Pokey/TK-II and Video portions. I've went over the board with my magnifying goggles until I'm almost cross-eyed and I can't find anything else to fix or reflow. I've gone through with a meter, checking continuity of all points to the next component/junction. I've checked for opens and shorts. I've double-checked and my UAV jumpers were pre-set for 800XL, which is what I think it is supposed to be set for 1088XEL. So far I haven't found any smoking guns.

 

Any ideas? Thanks.

 

 

 

[+Firedawg]

17 minutes ago, bfollowell said:

..........

Because of other issues that I've been having, I've went over most of the board several times in different ways, especially the Pokey/TK-II and Video portions. I've went over the board with my magnifying goggles until I'm almost cross-eyed and I can't find anything else to fix or reflow. I've gone through with a meter, checking continuity of all points to the next component/junction. I've checked for opens and shorts. I've double-checked and my UAV jumpers were pre-set for 800XL, which is what I think it is supposed to be set for 1088XEL. So far I haven't found any smoking guns.

 

Any ideas? Thanks.

 

Hello, sorry for the issues you are experiencing.  I had some screen issues with my build as well which ended up being contributed to a poor DVI cable and went a way when replaced.  I did not see that on your listed items covered. 

 

Mike

[+MacRorie]

13 hours ago, bfollowell said:

I'm not sure about the UAV composite output of my 1088XEL. Or rather, I am sure that it doesn't look good. What I'm not sure about is the reason.

 

 

 

 

 

 

 

Have you tried different cables?

Have you moved the existing cables away from power supplies/sources of RF interference?

Have you adjusted the color pot on the main board?

Have you tired the s-video connection?

Have you compared this output to other 8-bit outputs using the same cables and monitor?

 

All those items being said, you might also want to put ferrite cores on the cables.

 

You cannot compare composite to DVI, that is a comparison bound to tilt in the favor of the DVI and does not offer a realistic basis by which to judge anything.

Edited May 3, 2020 by MacRorie
Grammar

[+DrVenkman]

That looks like a color pot turned all the way low to me. You might also get something weird like this if you fed a luma-only signal into a composite input; the chroma signal being absent will lead to odd stuff with the video circuits of the TV. 

So if turning the color pot end to end doesn't give you color somewhere along the way, I'd try replacing your composite cable. One of the handy things about the XEL versus the XLD is that you can use standard composite or S-video cables instead of needing to make or buy a custom DIN13 cable.

[bfollowell]

Thanks for the suggestions.

 

I’ve tried other cables, and they all seem to provide the same crappy looking output. As I mentioned, my stock 800XL looks great on this same display; much better than this. As far as adjusting the color pot goes, wouldn’t that mess with things on all outputs, or does that only impact composite? DVI output color is perfect.

 

I don’t have any display that has an S-Video input.

 

[flashjazzcat]

Lack of colour is possibly a crystal frequency issue (i.e. running an NTSC chipset at PAL frequency or vice versa). Check jumpers and crystals. Isn't the little pot on the UAV some kind of phase adjust? In any case, I found that adjusting that pot can affect colour fringing.

 

EDIT: Re colour pot - try adjusting it as Herb suggests. It won't affect DVI output.

 

 

Edited May 2, 2020 by flashjazzcat

[bfollowell]

OK, I'll tinker with it later this evening. Thanks guys. I can confirm that my trim pot is turned completely clockwise, so I'm willing to bet that is it. I'll eyeball adjust it until I think the SpartaDOS screen looks about the right shade of blue, then I'll load up ACP and fine tune it by bouncing back and forth between my composite and my DVI outputs for comparison. Is there a better, more fool proof method for color adjustment?

 

Also, since I asked about it, what all output modes does the color pot affect? Composite and S-Video? You said it wouldn't affect DVI, I'm assuming since it is a 100% digital signal straight from the video chips. What about VBXE output, whenever I eventually receive it? Will it be affected by color pot adjustments?

 

Also, silly question but, in all my electronics experience, I never messed much with crystals. When I installed mine, I trimmed the leads down pretty far, so that it barely sets above the socket. I'm fairly certain nothing is touching anywhere. That should have any impact on the function of the crystal should it?

 

Thanks again guys!

[flashjazzcat]

There's not much point in trying to tune the analogue composite/s-video output using the DVI output as a reference; it will never be quite the same since Sophia is using a built-in colour palette of its own (and is of course entirely digital). Sophia is also outputting 'PAL' colours similar to those generated by VBXE. Your analogue NTSC video has a completely different palette.

 

The colour pot on the motherboard only affects UAV and the legacy circuit it replaces. VBXE - although it outputs an analogue RGB signal - has its own on-board palette much like Sophia.

 

Crystals should be fine flush with the board, I would think. The casing would have to be directly shorting to a via underneath the crystal, and I don't think there's any possibility of that happening on the board.

 

[bfollowell]

OK, I didn't do anything scientific, and I didn't tweak too much. I just looked at the screen and kind of eyeballed it in until I thought, "yeah, that's about the shade of blue I remember"

 

Once I got the color about right everything else looked pretty good. I mean, the letters aren't crisp clear perfect like what I seem to remember seeing in others' images of their UAV output, but they could've easily been using S-Video, where I'm using composite. It still looks pretty good. Definitely better than I remember on any display I ever had as a kid or a young adult, and better than my stock 800XL. I think the multicolored/artifacted letters in the U1M menu were making everything look worse than they really were. And Marlin, you're right, it's silly to try and compare back to DVI or VBXE output. Even knowing in your head that they're going to look better isn't enough to really prepare you for how much better they look than even the best possible composite image. It's still enough to leave you thinking that there must be something wrong. I still have those slight little lines at either side of the screen, but that's nothing major. Overall, I think it's a beautiful composite image. And I'll only be using composite when I feel I really need to for some specific title that makes good use of artifacting. I figure 95%+ of my XEL use will be with DVI or VBXE.

 

Now I need to troubleshoot some more on the keyboard/boot issues that I'm still having. I think I'm going to order another, different PS/2 keyboard as well, just to have another to try it with. Maybe I'll order one of those Chinese composite/S-Video to HDMI converters mytek purchased recently as well. I know they won't hold a candle to a RetroTink, but they're only a fraction of the cost too, and I think they'll serve my purposes just fine.

 

Thanks again guys!

 

[+DrVenkman]

Are you running that composite straight into the TV or via a converter? My Samsung LED upstairs in my retro-room has a terrible internal scaler. Direct composite into the TV looks substantially worse than running it through even a cheap Amazon/eBay type Chinese scaler to HDMI. 

[bfollowell]

You got it in one. Straight into the composite input on the back of an 8-9-year-old Samsung 1080p LED TV.

 

[+Stephen]

Yeah - I have not found any modern LCD panel with composite that could take a signal from any of my A8 devices and not make it look like total ass.  Any CRT using composite, looks perfectly fine.

[+DrVenkman]

So this isn't an XEL obviously, but here's a comparison I did today of my UAV composite-modded 4-Switch Woody through the RetroTink versus my TV's internal scaler. This particular TV (2013 Samsung mid-range LED, still has a composite input).

 

First the RetroTink, Composite to HDMI:  

 

 

Next, the UAV composite straight to the TV. Note the much more pronounced border effects and the weird horizontal dot pattern under every line transition (ignore the dimmer gold - the chalice was there in the second pic so gold was color-cycling).

 

Edited May 3, 2020 by DrVenkman
Formatting

[rockdoc2010]

I sincerely wish to apologize I dropped many f bombs and I was upset but very unprofessional.

I hope that I haven't offended anyone.

 

Peace!

 

Douglas

[bfollowell]

I played around with some more troubleshooting today. I've noticed that F10 no longer works during boot up. That's the HELP key and should take me into the U1M setup. F12 still works to do the same, but F10 used to work, and now it doesn't. The only thing that has changed since it did work is that I removed the left POKEY chip to get at the PIC and other components underneath when I was checking continuity. Nothing is bent. All the pins are making good contact. Everything still looks good. F10 just no longer works. So, anyway, I'm still leaning towards left POKEY/TK-II issues, but I haven't found any smoking guns yet.

 

I'm curious, when I press Alt-X to confirm that I'm in XEGS/XEL/XLD mode, I get a long key press tone after every letter prints on the screen, sort of like it was a teletype machine or something. I get the same thing if I press Alt-F1 to verify version and Alt-F2 to see the configuration settings. As you can imagine, the configuration settings make a lot of loud noise. Is this normal behavior? I don't seem to recall this from before, when the F10 key was working, but when there were other boot issues.

 

Anyway, someone please let me know if this is normal TK-II behavior or not. If not, I think I'm going to try reflowing solder on everything Left POKEY/TK-II related, whether it looks questionable or not.

 

Thanks.

 

[+mytek]

5 hours ago, bfollowell said:

Anyway, someone please let me know if this is normal TK-II behavior or not. If not, I think I'm going to try reflowing solder on everything Left POKEY/TK-II related, whether it looks questionable or not.

It's not .

 

[larryleffaovell]

Another one came up to live. Many thanks to @tf_hh, who assisted me with this project remotely, enhancing my skills in soldering and electronics in general.

 

My 1088XEL/PAL woke up at very first run, but with two issues:
- The system starts unstable and crashes after exactly 10 seconds
- 2nd Pokey available in U1MB, but sound only from left speaker, no stereo

 

I solved the sound issue by inspecting the PCB against schema, the signal of the second pokey never reached AUD-AUX; reason was a wrong type of transistor/Q4, which in turn destroyed C9. Q4 and C9 renewed, stereo!

 

The first issue is still unsolved, although tf_hh and I have already measured a lot, exchanged SALLY, ANTIC, GTIA and PIA, I've re-soldered evey spot, but symptoms are always the same:
System starts from cold and crashes after exactly 10 seconds with garbled and/or jumping screen. I can reset the system and after doing this some times (for ~30-45 seconds), the system comes up normally and is running stable then for hours - until next start from cold.
Another symptom which may depend on this issue, is that the U1MB is sometimes starting with cleared NVRAM. Swapped U1MB against another, working one, but same symptom.

 

No other hardware upgrades beside U1MB and UAV attached for now. VLSI chips are coming from a working 800XL/PAL.
 

Any hints are welcome.

Edited May 4, 2020 by larryleffaovell

[+DrVenkman]

13 minutes ago, larryleffaovell said:

Any hints are welcome.

Do you have access to an oscilloscope? I’d check the waveform shape and stability of Phi2.