1088XLD - Custom A8 Computer in 1050 Drive Case

[ivop]

Nice! This is exactly why the jumpers where there in MIDI Muse, to use an external keyboard to drive the internal WaveBlaster synth!

[+mytek]

Nice! This is exactly why the jumpers where there in MIDI Muse, to use an external keyboard to drive the internal WaveBlaster synth!

 

Unfortunately this is not possible on the latest MIDI XEL II since that only has the ability to route the MIDI-OUT to the built-in synthesizer. However it probably wouldn't be all that difficult to write a simple program to loop the MIDI-IN data over to the output .

 

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

 

Now for some mouse fun on the XLD...

 

https://www.youtube.com/watch?time_continue=4&v=zLAPllKPdHc

 

Download: PAD (NTSC).xex

Download: PAD (PAL).xex

[ivop]

 

Unfortunately this is not possible on the latest MIDI XEL II since that only has the ability to route the MIDI-OUT to the built-in synthesizer. However it probably wouldn't be all that difficult to write a simple program to loop the MIDI-IN data over to the output .

 

I think (judging by DrVenkman's video) that midirec can do it. It says right there on the screen, MIDI THRU off. Turning it on should relay all incoming events to MIDI OUT.

 

Edit: MIDI Muse also had this functionality so it can even be used without an Atari, as long as +5V power is supplied.

Edited April 9, 2019 by ivop

[_The Doctor__]

HUUH?

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Unfortunately this is not possible on the latest MIDI XEL II since that only has the ability to route the MIDI-OUT to the built-in synthesizer. However it probably wouldn't be all that difficult to write a simple program to loop the MIDI-IN data over to the output .

 

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

 

Now for some mouse fun on the XLD...

 

[media]https://www.youtube.com/watch?time_continue=4&v=zLAPllKPdHc[/media]

 

Download: PAD (NTSC Version)

Download: PAD (PAL Version)

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WTF moment, since when?

Edited April 9, 2019 by _The Doctor__

[Brentarian]

Dr. V nice work!!! Looking forward to completing one of these boards, maybe two. Between homes at the moment and everything is in boxes:(

Hi Firedawg,

I see that your location is Atlanta. Will you be attending VCFSE this year? I will have my 1088XLD on display.

[+mytek]

 

I think (judging by DrVenkman's video) that midirec can do it. It says right there on the screen, MIDI THRU off. Turning it on should relay all incoming events to MIDI OUT.

 

Edit: MIDI Muse also had this functionality so it can even be used without an Atari, as long as +5V power is supplied.

 

I'll go check that out .

 

 

 

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WTF moment, since when?

 

 

Try it now, it should be fixed.

[_The Doctor__]

It is indeed.

[rockdoc2010]

Killing ME! I need a public release!

 

Thank all of you that are working so diligently to vet this board.

 

Douglas

[+Stephen]

I'm really hoping to do a power up test on mine this weekend. I don't have what I need to make the video cable, but I will pick the points from the PCB just to test this.

[+DrVenkman]

I'm really hoping to do a power up test on mine this weekend. I don't have what I need to make the video cable, but I will pick the points from the PCB just to test this.

 

Fingers crossed for you, Stephen! Looking forward to hearing your results.

 

I had intended to order my front panel this weekend but taxes are due, my car registration is also due (which frankly I had forgotten about!) and, well, I *may* have just bought an oscilloscope, lol. So front panel in two weeks. I need to buy paint for my case, clean it up thoroughly, etc. That will keep me busy for now.

[+DrVenkman]

Heh. The XLD's internal S2 player works simultaneously with outboard (external) MIDI players connected to the MIDI OUT jack. I actually started this experiment expecting that if it worked, I'd have had to connect to the MIDI Thru jack, thinking that enabling the S2 would sort of "re-direct" the OUT data to the internal synth. Nope, I was wrong.

 

This adds some fun possibilities.

 

[+DrVenkman]

When I was building my board, I was basically finished a few days before I was able to succesfully boot the machine. Turned out I had installed one diode backward on the main PCB (diode D3, I'm lookin' at you, you little sumbitch! ) That one is designed to go in "backwards" or reversed compared to several others neaby in the clock circuit, and while the board silkscreen clearly shows the correct orientation, I simply overlooked it. But in the process of tracking down the issue, I decided I needed a "real" oscilloscope. I had been fooling around with a little $60 USB-based device (a Hantek 6022BE) connected to a Raspberry Pi as an interface and display, but it was awkward to set up, kind of a pain in the butt to use and limited in terms of sample rate, measurements, etc.

 

Anyway, I convinced myself to spend some hobby money on a decent hobbyist scope and it arrived this week. For comparison sake, here's the OSC clock oscillator circuit that comes from the NTSC crystal in my machine as it goes into pin 28 on the GTIA, measured by my little Hantek USB scope. The Raspberry Pi it's connected to is running OpenHantek, an open-source replacement for the Windows-only Hantek software the device comes with:

 

 

Now here's the same signal measured tonight with my new "real" scope:

 

 

While I was at it, I measured the Phi1 and Phi2 clock signals generated by the SALLY chip as well. If the OSC is the heartbeat of the Atari computer, the Phi2 is its brainwaves.

 

 

 

Edited April 18, 2019 by DrVenkman

[+DrVenkman]

A few more weeks, my front-panel arrived and so another step closer to "done."

 

 

 

 

[+mytek]

Looks great . Now you just need to rebrand it as "1088XLD" instead of the old 1050 label.

 

Speaking of which, I ended up using a Krylon Clear Matte finish over my new label to protect it from finger prints. First I laid down a couple of coats, and then after it dried, I pointed the nozzle up in the air, letting it drift down on top of the label, thus giving it a bit of texture. Came out very nice .

[AtariGeezer]

I'm really hoping to do a power up test on mine this weekend. I don't have what I need to make the video cable, but I will pick the points from the PCB just to test this.

How's your progress coming along? inquiring minds like to know

[+Stephen]

How's your progress coming along? inquiring minds like to know

Nothing but problems at work leading to 60 hours a week and 8 hours per week of yardwork. I haven't touched the board since assembly was finished. I haven't ordered my panels.

 

Also dealing with a foot problem causing me great pain and difficulty walking. Making an appointment with a specialist in the next few days to see what is going on with that.

[Kyle22]

@Stephen: I hope your foot gets better soon. If it's gout, try (holding your nose) and taking shots of vinegar. I am afflicted only rarely (years), but that takes it OUT in a day or 2.

[+mytek]

VGA Output on 1088XLD






Boards (Carrier PCB and GBS-8200)




Flashing Firmware for Atari Video Modes
(Using PICkit2, although an AVR Programmer Port is also Provided)




Installed




I'm still fine tuning the hardware design (not happy with the stacked bottom side extended female board connectors), but it's getting pretty close and currently produces an excellent picture on my Sony SDM-HS75P VGA Monitor. It will require a few tweaks in the Monitor's setup menu such as clock, phase, and position, but once done everything's locked in from that point forward. The ATtiny861 chip gets flashed with the GBS-Control code provided HERE. And the only adjustment on the GBS-8200 board is to set the 3 RGB input trim pots to their fully counter-clockwise position which gives maximum gain required by the Sophia's 0.7V outputs (original trim pot settings were assuming an Arcade machine's 1V RGB outputs).

I'll be purchasing a short DB15 Male to Female extension cable and making a suitable hole over one of the SIO connectors to make one side of the cable into a panel mount connector, so as to get access to the VGA signals outside of the case.

Since a 50 Hz PAL signal does get converted to 60 Hz, this allows any VGA monitor to work for PAL or NTSC, but as always the better the quality monitor, the better will be your results. I tried three old Dell monitors, and although they all worked, my Sony looked sooooo much better, giving a bright and crisp, high contrast ratio display.

Being as how I'm running this board off of the 1088XLD's 12 VDC supply, I get some much needed use of that circuit and leave the 5 VDC side free for the computer.

Non-Interlaced Display

So here's the downside. Interlacing has been disabled, which in 95% of the applications, games, and demos, doesn't matter. However when programmer's have resorted to a forced interlace mode via clever coding, it will not render correctly, yielding a 'sparkly' look. So something like FlickerTerm will not work. However on the plus side, due to the excellent resolution of the VGA monitor 'The Last Word's' software 80 column mode looks superb .

Where to Buy GBS-8200 Arcade Board

The GBS-8200 Arcade RGB to VGA converter board can be purchased from eBay for around $17-20 (many times including FREE shipping). There is also a new version that essentially bolts on a VGA to HDMI chip for around $40 which should still work with my carrier board, but I don't know how good the HDMI output looks.

[JoSch]

WOW.

[+mytek]

WOW.

A lot of the credit needs to go to Simius's Sophia RGB video board which is driving the quality that you are seeing. The problem is that over here in the US we have next to nothing that will display 15 KHz RGB. But VGA is a different story. So the key was to find something that could make the transition from that to VGA without corrupting the signal, or adding excessive lag. And it needed to be inexpensive, which the GBS-8200 definitely is. Only problem was that the original firmware was a bit sucky, but luckily other people had worked out a solution for that which I have implemented into the carrier board.

 

The GBS-8200 board is big, but thanks to the room in the 1050 case that's no problem.

[JoSch]

Actually, the "WOW" was directed at you.

Not so much the quality (it's great as is the quality of a VBXE board, which I prefer), it's your idea to do this board.

You seem to be on a roll here.

Edited May 20, 2019 by JoSch

[+mytek]

Actually, the "WOW" was directed at you.

Not so much the quality (it's great as is the quality of a VBXE board, which I prefer), it's your idea to do this board.

You seem to be on a roll here.

Thanks for the WOW .

 

The XLD project is about putting in everything I learned when doing the XEL, and then incorporating the things that I felt were missing in order to make a more complete system. The bulk of this was done several months ago with the main board set, but I still felt that the video options were missing a key element. As I mentioned RGB gives us a great picture, but over here in the states we don't have many choices to be able to display it. Of course there is the option of using the Sophia DVI version, but that knocks the VBXE out of the running, and then there is the problem of finding a monitor/core that matches up and works. The GBS-8200 RGB to VGA board seemed to be the ticket, but when I first tried it, I was disappointed by some of it's quirks which needed to be ironed out before becoming a viable option.

 

The GBS board has been around for quite awhile, and it's dropping price attracted a lot of hobbyist interest and tinkering. So when I starting looking across the net, I found several code projects and offshoots of such that tweaked the GBS into something more suitable for our needs. The one that stuck with me, and is now incorporated into my board, provided the complete source code, as well as a ready to flash hex file. And unlike some of the other solutions, it only requires a single inexpensive (less then $2) Atmel MCU chip. Having the source code also gives us a future upgrade path, if needed.

 

And of course building this into the 1050 case gave me all kinds of room that was begging to be used.

[JoSch]

May I ask, what the quirks are? I have a similar boards as the GBS. By the looks it could be the same, but I have to check, when I'm home.

Also, I have some Arduinos lying around, so I could use them, as I assume this board is for the XLD only.

Edited May 20, 2019 by JoSch

[+mytek]

May I ask, what the quirks are? I have a similar boards as the GBS. By the looks it could be the same, but I have to check, when I'm home.

 

The original firmware settings of the video scaler chip on the GBS-8200 tries to do a de-interlacing of the RGB source which has a tendency to blur or cause jitters to the edges of images, and is of course not even required coming from our non-interlaced video source. And the other very annoying aspect is that each and every time you power-up the board it displays a Chinese symbol splash screen, which also adds considerable delay before the actual video is passed through.

 

To see the power-up splash screen, advance to time index 4:09 on this video.

 

https://www.youtube.com/watch?v=q3J4QJsn0ig&t=1s

 

The noise issues mentioned in the YouTube video I found were eliminated by better power supply filtering which I've implemented on my carrier board. I also have both a top and bottom ground plane which should serve to eliminate noise pickup from the XLD circuits down below.

 

 

 

Also, I have some Arduinos lying around, so I could use them, as I assume this board is for the XLD only.

 

Yep this is XLD specific, but it could be made to work for other systems by eliminating the bottom side female headers, and simply wire into the input side of the power filtering circuit to a power supply of your choice.

 

Please note that when using this method of replacing the scaler chip setup, that the onboard menu buttons will no longer work. However they won't be needed, so no great loss. And be sure to jumper P8 on the GBS board to tell it to use the external I2C communication coming from the Arduino.

[Mr Robot]

Oh I have to make that I2C MCU board for my external GBS!