2023 Advanced PCB Remake For the 800XL -- Revision 1.1

[seastalker_returns]

I am beyond excited to find this thread. I'm interested in this board for another build and now wonder if this talk of bad crystals may be why I only get black and white analog video (Sophia digital works fine) from this project last year:

 

[Jfcatari]

Don't worry about this board.  It is perfect.  I built one and have 2 more to do.  This is a great 800XL Remake board.

 

I did discover a little issue with certain crystals being used that only presented B/W when running on composite video out to a tube TV.  Composite and Svideo had no issues with color when using composite to HDMI, svideo to HDMI, composite to VGA, or svideo to VGA.

 

With the help of others in this thread, we have a solid like of crystals to use. 

 

You can always use the original Atari as well with no problems.

 

[seastalker_returns]

Oh I'm ready for one... hopefully I am on the next batch waiting list...

[reifsnyderb]

I just updated the next board and it might be done.  I need to do some testing yet.

[jasenr]

How does one get on the list?

[reifsnyderb]

I was planning on testing out the next changes so as to make sure they would work.  I didn't do it yet after being held financially responsible for the theft of a package off of somebody else's porch.

 

https://forums.atariage.com/topic/358571-porch-pirates

 

I am taking some time off.

 

Edited May 16 by reifsnyderb

[reifsnyderb]

I've been slowly working on the next board revision.  Revision 1.2.

 

Currently, I've made the following changes:

 

Remove re-settable fuse -- done (available value was rather high anyhow)
Add S-Drive simple capability -- done (added breadboard)
Make minor video trace improvements -- done
Denote composite video only components -- done
Add +5v and GND input to silksreen -- done
Added optional R1 to cleanup B Phi2 -- done -- needs tested

Improved power routing to cartridge -- done
Add capacitor footprints for crystals -- tests show the footprint layout needs changed
Added minor fix for ground lines around Phi2 near PBI -- done
Add MapRAM capability -- done

 

Tonight, I tested two different layouts for the crystal and capacitors.  The first layout was to ground the capacitors and the second was to put the capacitors in series with the crystal....as has been tested successfully.  I used the upper left breadboard section and wired in an off-the-shelf crystal with the capacitors.  The capacitors do have to be wired in series with the crystal to work.  I am going to leave them installed so as to re-claim my Atari crystal.

 

Last night, I spent an hour contemplating MapRAM and realized that by re-wiring a few connections and modifying the program on two PLD's, MapRAM could be added.  I don't know if anyone would fine it useful, but, why not?  (Besides, @xxl will like this.   🙂   )  Tonight, I tested the MapRAM changes and they appear to be working!  For example, if I enable both the PBI RAM and MapRAM, I can save something to $D600, enable MapRAM, and find it at $5600.  So, the next board will have the capability of addressing all 64k.

 

Having the breadboards available makes these sort of tests pretty easy.   🙂

 

 

Crystal installation:

 

 

 

MapRAM jumper added:

 

 

 

Back of board:

(Note wires for MapRAM and standard crystal installation.)

 

 

 

 

 

 

 

 

 

 

 

 

Edited September 18 by reifsnyderb

[Jfcatari]

6 hours ago, reifsnyderb said:

I've been slowly working on the next board revision.  Revision 1.2.

 

Currently, I've made the following changes:

 

Remove re-settable fuse -- done (available value was rather high anyhow)
Add S-Drive simple capability -- done (added breadboard)
Make minor video trace improvements -- done
Denote composite video only components -- done
Add +5v and GND input to silksreen -- done
Added optional R1 to cleanup B Phi2 -- done -- needs tested

Improved power routing to cartridge -- done
Add capacitor footprints for crystals -- tests show the footprint layout needs changed
Added minor fix for ground lines around Phi2 near PBI -- done
Add MapRAM capability -- done

 

Tonight, I tested two different layouts for the crystal and capacitors.  The first layout was to ground the capacitors and the second was to put the capacitors in series with the crystal....as has been tested successfully.  I used the upper left breadboard section and wired in an off-the-shelf crystal with the capacitors.  The capacitors do have to be wired in series with the crystal to work.  I am going to leave them installed so as to re-claim my Atari crystal.

 

Last night, I spent an hour contemplating MapRAM and realized that by re-wiring a few connections and modifying the program on two PLD's, MapRAM could be added.  I don't know if anyone would fine it useful, but, why not?  (Besides, @xxl will like this.   🙂   )  Tonight, I tested the MapRAM changes and they appear to be working!  For example, if I enable both the PBI RAM and MapRAM, I can save something to $D600, enable MapRAM, and find it at $5600.  So, the next board will have the capability of addressing all 64k.

 

Having the breadboards available makes these sort of tests pretty easy.   🙂

 

 

Crystal installation:

 

 

 

MapRAM jumper added:

 

 

 

Back of board:

(Note wires for MapRAM and standard crystal installation.)

 

 

 

 

Congrats on rev 1.2....I will be interested when they are ready!