Greetings, all..

I created the ExpressPCB 8052 SBC at this address :

http://www.silcom.com/~pelican2/SBC_INTRO.html

This board is mostly for students or neophytes, with modest features. The RS232 is achieved with discrete transistors, and works fine. Cost is about US$65 for 3 bare boards, delivered in U.S., in about 1 week. I don't know about international orders. Boards measure 2.5 x 3.8 inches. Also room for an 18 pin PIC micro on the board.

I have never had ANY problems dealing with ExpressPCB, ( used them many times ) and recently started using EagleCAD for other tasks. ExpressPCB recently added schematic capture, but I have no schematic CAD file for this board.

The SBC on my website also includes a simple IBM download program that will transmit a text file to the SBC, ( with BASIC-52 interpeter ) so that a program can be created and edited with a word processor, on an IBM.

Regarding the original question : If single sided boards are truly essential, why not simply make two separate boards, ( one for each side, copper side facing out ) and just 'sandwich' them together... ? This assumes the resulting board thickness is not an issue, and components can be soldered on both sides. ( sockets = ? )

EagleCAD identifies many vendors on their website that can work directly from their CAD files. It is not so easy to learn or use, but it is much more agile than ExpressPCB, and the resulting CAD files are highly portable. I have previously used it to order boards from CustomPCB in Malaysia, with good results, cheap prices and fast delivery :

http://www.custompcb.com/

regards / R. Simmons