U1MB with VBXE -- Where is VB pin on U1MB?

[Jeffrey Worley]

I'm working on an 800xl with a vbxe installed by another technician.  This is a United States machine, NTSC, so Scart is kinda foreign here, like non-existent.  The previous tech did not install a video out on the vbxe, the only video out was the stock DIN for composite, which is dumb.  So no one has yet seen this VBXE actually display video yet.

 

I've installed a DB9 with Audio L and R, GNDs to all the appropriate scart pins, R, G, B, rgb control, and even Csync.  Then I built a breakout cable to connect the DB9 to the female scart connector on a Scart to HDMI adapter using modified Atari SIO pins as substitutes for the scart blade pins, (which don't exist here in North America).   Csync is not connected to anything as yet, I connected it to a spare pin on the db9 to have it available for some future monitor project.

 

Now for the question:

 

The vbxe's J1, pin 8 was connected to pin 9 of the 74ls138.  I'd like the U1Mb to control the VBXE.  I don't see a "VB" pin on the U1MB, the conversations I read here  on Atariage seem to conflate the M1 pin with the VB pin, with dire warnings as to connecting either power or ground to this pin.  What should I connect the VBXE's select pin to?  Another question is, the installation docs, if you can call them that, from Lotharek, indicate that J6, pin 1 of the VBXE shouldbe connected to pin 3 of U21 on the 800xl, a 74LS74.  I see no U21, no 74LS74.  Does this mean 

 

P.S. Getting RGB to work on an American TV is a real bear.  Our gear never supported it, there are only the Commodore 1800-ish monitor and the Atari ST monitors that support it and I'd rather not use a giant tube when I can make a flat panel work.  So far I have a Scart-to-HDMI converter working for the composite signal.  I'm working on getting the RGB to switch on the scart adapter.  That is interesting if the client wants 4:3 aspect ratio, I gather, as that needs 9 to 12vdc on pin 8?  I think he may have to be happy with 16:9, if I get that working by putting 5vdc to pin 8 of the scart.  Well, wish me luck.

 

Thanks,

 

Jeff

Edited September 23, 2019 by Technoid Mutant
Amplifying information

[flashjazzcat]

6 minutes ago, Technoid Mutant said:

What should I connect the VBXE's select pin to?

VB. If it isn't labelled VB, it's WB.

[Jeffrey Worley]

3 minutes ago, flashjazzcat said:

VB. If it isn't labelled VB, it's WB.

I have a WP, not VB or WB.  that is pin 5 of P4.  The pins go: s0,s1,m0,m1,WP, but the machine lives if I plug the select pin into WP.  Lemme see if that's the fix.  THANKS!

 

Edited September 23, 2019 by Technoid Mutant

[flashjazzcat]

Sorry: WP not WB. Working from memory. It's the correct pin.

[Jeffrey Worley]

2 minutes ago, flashjazzcat said:

Sorry: WP not WB. Working from memory. It's the correct pin.

Awesome.  It doesn't give me video on A1200xl.com, but everything here on the VBXE demo dir is in PAL, probably.  Some of the stuff says it won't run on NTSC machines.  Any suggestion on a good test for the board, to verify that it works?  I'm able to select the address of the VBXE now in the U1MB menu, that's an improvement.

 

Jeff

[flashjazzcat]

Try the SDX 80 column driver: S_VBXE.

[Mr Robot]

If the panel supports VGA you can plug the vbxe into a GBS8200 to get a VGA signal.

 

[Jeffrey Worley]

3 hours ago, Mr Robot said:

If the panel supports VGA you can plug the vbxe into a GBS8200 to get a VGA signal.

 

The problem with that particular board is that it is naked.  It's not expensive, which is nice, but the fellow who'll be using the machine wants something more rugged.  I may get one for myself and an ST that's coming my way soon.

 

Best,

 

jeff

[Mr Robot]

There's a thing for that

https://www.thingiverse.com/thing:2301666

 

Eventually there will be XL/XE themed things for it

[Jeffrey Worley]

Thanks all!  I got the board working beautifully,  used this converter:  https://www.amazon.com/gp/product/B0177DG71S/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1 with this cable: https://www.amazon.com/gp/product/B01GW6126G/ref=ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&psc=1.  I cut the cable in half, pinned it out, and wired a 9 pin male to the cut end.  All signals go through the db9 I mounted on the XL's back, stereo left and right, grounds, RGB scart, Composite video (which is amazing by the way, best I've ever seen).  I used the pinout for Amiga RGB, so any standard rgb cable will work for an old tube-set rgb monitor.  Else, you can use my custom scart cable, this adapter, and a flat panel display.  I'm so stoked.

 

(After getting it all hooked up and neat, my problem was that the little 'scart to hdmi' adapter I'd gotten for 6 beans on Amazon turned out to be a Composite converter, not an RGB converter.  So I saw no vbxe output until I got a converter that supported rgb.)

 

If anyone needs help with VBXE installs, just message me and I'll give you all the help I can.  Now that I have it fully sussed it will be a snap.  I'll install it for you if you want, but shipping is a sad expense.

 

Speaking of Stoked,  Shoutout to FJC in Newcastle, home of coal.  I thank you kindly for entertaining my neophytic questions ?

 

Best,

 

Jeff

[+Stephen]

Beautiful isn't it?  Welcome to the (tiny) VBXE club, I'm less than 3 weeks into using my first one.

[flashjazzcat]

What's the name of that VBXE demo with the overlaid text again?

 

[Jeffrey Worley]

2 minutes ago, flashjazzcat said:

What's the name of that VBXE demo with the overlaid text again?

 

In the Examples.zip file available on Lotharek's website, this particular demo is located in Examples/FX/Electron/scroll/skxx.com, where xx is an integer.  there are several variations there.  Here's the file.

 

Best,

 

Jeff

examples.zip

[Jeffrey Worley]

56 minutes ago, Stephen said:

Beautiful isn't it?  Welcome to the (tiny) VBXE club, I'm less than 3 weeks into using my first one.

Well, this vbxe machine isn't mine, unfortunately.  Now that I've seen it work, I gotta have one.  There goes another buncha money.  Lothahrek is killin' me man.  :-))

 

Somebody stop me. :-))

 

Best,

 

Jeff