OK, I know the smart way to run 7-segment displays is to use electronics that oter people have already designed, such as FSBUS or IOCards, but few people ever described me as smart :-(The small flat card with the power and PC connection can run up to seven of the upright cards with the 5x7-segment. It has only one PIC, one microswitch and three resistors (It's designed to be programmed in situ - without the programming requirement it would need only two resistors) and is so simple in wiring I saw no point in etching a PCB for it.The vertical display card has the driver chip, the 7-segs, and a pot for brighness control. I etched a PCB for it because it otherwise involved 40 seperate wires from the chip to the segs, but it wasn't essential.Here's a link to it in use.http://members.aol.com/rickgalty/RadioStack.mpgRichard

You drasticaly forgot to mention basic info in this post, i think ... read it again!

LOL, you're right.OK, the main board is based round a Picaxe-18X, which is similar to a Basic Stamp only a lot cheaper.Here is the layout I used for the board, except that in the one in the photo I didn't bother with a PCB, I just wired it on perfboard.http://forums.avsim.net/user_files/161177.jpgOne of the eight available outputs provides the "clock" pulse to all the LED boards, the other seven can each provide a "data" pulse to one LED board.The LED boards are laid out on PCB's - here is the layout:http://forums.avsim.net/user_files/161178.jpgThe board is based around an M5451 chip, which allows individual control over each segment of 5 x 7-segment LEDs - or, of course, 35 individual LED lights.The PICAXE is programmed in a simplified version of Basic, and the interface to FS2004 is a Visual Basic program acessing FSUIPC.The PICAXE chip costs $7.99, and I paid about $3 each chip for two sleeves of M5451's. The controlling cost, therefore, is the LEDs - again, I got lucky and bought them off eBay for less than $1 each in bulk.The only other components are a few resistors and plugs. I estimate about $10 for the master board, and about $9 each for the display boards, all fully populated.Richard

Final question:What does these prints conect to ? USB/Serial/Parallel/PCI :(Then if I understand right, you need 1 master board (the upper sheme) and you can host 7 led-boards ?

I have it connected through the serial port, but you can also use any USB-serial adapter. A USB input chip could also be wired to the master board, but why complicate matters?Yes, one of the master cards can directly drive 7 of the LED boards. Since the M5451 chips are latching, you could also use multiplexing to drive more, although the coding would get more complicated. With 'charlieplexed' switching transistors, you could theoretically get up to 48 LED boards... be a horror to code that though!Additionally, I've embedded "Hello Board 1" protocol into the VB, so I could have a LOT of the master boards connected to the same serial port. The more you have, though, the more likely you'll be crossing data - that won't result in any bad displays, but would make the board wait till the next sequence for it's update. I currently have the VB updating 20xsec, but if I were to go to more than three or four masters, I'd need to decrease that, to stop the VB from still being busy sending when the data is updated.Richard

No sooner had I posted the above than I saw in the PICAXE forum that they now sell a USB-Picaxe cable that allows you to use the PICAXE on any USB port.Richard