ABBUC e.V. Forum

Dear all,

I have a few questions regarding XE remake (purchased from ABBUC)

1.) I have vbxe, which i am still wiring.
a) what do i need to wire from vbxe to video setup area (10 pin block) any documentation on that?
b) why do I need +5v (sj1) for vbxe, as there are no need for +5v on any vga 15khz? is it needed and for what? ( I need only R,G,B,Csync, Vsync and GND for generic VGA 15khz setup).

2.) I have atari BASIC native rom (24 pins) and no changes made to the pcb. it is unclear - do I need to do the mod on the pcb for original basic chip or it is only needed for custom eeproms?

3.) I assembled the whole board, but my picture over composite signal is jumping (up and down one or two lines every quarter second)? what could be leaking or where should i check?

Would appreciate any ideas,

Thank you,

Serhii

wolfius hat geschrieben: ↑

03.08.2023 16:33

1.) I have vbxe, which i am still wiring.
a) what do i need to wire from vbxe to video setup area (10 pin block) any documentation on that?

You will find the setup infos in the VBXE documentary, i.e. it´s the file "vbxe2-con.pdf". The pin CSDxx must be tight to pin 9 ($D6xx) or pin 7 ($D7xx) of the 74LS138 chip (U2). When you want to use the common $D6xx area, you can also grab the $D6xx signal from the header below the ECI connector. Most right pin, bottom row.

wolfius hat geschrieben: ↑

03.08.2023 16:33

b) why do I need +5v (sj1) for vbxe, as there are no need for +5v on any vga 15khz? is it needed and for what? ( I need only R,G,B,Csync, Vsync and GND for generic VGA 15khz setup).

What do you mean with SJ1? I know only about J1 when talking about VBXE (it´s the 10 pin connector mentioned above) and J1 is the SIO connector at the XE replica PCB. VBXE grabs power from the ANTIC socket, so there´s no need for extra power connections.

wolfius hat geschrieben: ↑

03.08.2023 16:33

2.) I have atari BASIC native rom (24 pins) and no changes made to the pcb. it is unclear - do I need to do the mod on the pcb for original basic chip or it is only needed for custom eeproms?

Uh, didn´t know exactly. I think, the early boards with 24pin only possible will work, the other one maybe need a patch. Will look later. But system will run without BASIC ROM fine for a test.

wolfius hat geschrieben: ↑

03.08.2023 16:33

3.) I assembled the whole board, but my picture over composite signal is jumping (up and down one or two lines every quarter second)? what could be leaking or where should i check?

Did you already make the corrections suggested by Panos (creator of the replica).

In general, I would strongly suggest to join the AtariAge thread about it, you will find more info in english language.

Regards, Jurgen

Dear tfhh,

Thank you for your prompt reply. I was late to see it.

Got the board to work with a different monitor, no artifacts.
Still i dont understand the role of SJ1 (if you turn ober the board, close to power jack, there would be solder joint 1 (sj1), which routes +5v to the video setup.

Best,
Serhii