morgana@canard.wrc.xerox.com (Steve Morgana) (03/12/91)
I bought a lucas board about two years ago and have finally gotten around to building it. To make a long story short, it did not work the first time, (nor the second or third...) I have played the tricks suggested with U9 and can get it to boot the Kickstart disk, but at the end of the kickstart load, it flashes the screen a bit and puts up a YELLOW screen. I believe that the board is mostly working and I am having a heck of a time trying to find out what the problem is. I have one of the original A1000's, with its original PALs. I dont think it is a PAL problem since the system runs fine with the 68000 in place and a starboard II and LIVE hanging on the expansion buss. I have been testing the LUCAS board with no expansion boards attached, a 20mhz 68020 + 68881, a 10, 16 or 20 mhz clock, and Kickstart 1.3. I have a rev 3 circuit board and the PALS were bought with the board. I belive the disk that came with the board says LUCAS 1.1 on it. Does anyone know if there was a rev to the pals or the board that I may have missed? Also, does anyone know how to set the jumpers that are on the board? None of the documentation that Brad sent with the board mentions the proper setting of the jumpers. Looking at the circuit it seems that jumpering the 68020's fc2 to the 68000 socket's fc2 seemed like a likely thing to do. However jumpered or not, the board still behaves the same way. We put a scope on it at work and saw a lot of noise on its ground, and took care of that by running wirewrap wire from a common point to each chips ground pin, and from the common point to the motherboard ground. This quieted the ground quite a bit and improved things somewhat, but it did not get us past the yellow screen. A few interesting things that I have noticed is that there is more to the boards flakeyness that the U9 thing. As a matter of fact, I have noticed that certain chips MUST be TI parts in order for the board to do anything more than flash the power LED. Also, suppose I have a chip configuration that allows kickstart to boot up to the yellow screen: If I then power the system down, and swap some equivalent parts around, the system probably will not even be able to read the kickstart disk at all!! Have other LUCAS builders had a lot of problems debugging their boards? Or am I the only lucky one? Those of you that had problems, how did you solve them? Any help will be grately appreciated, I really would like to see this board work. Thanks Stephen (please ingore the reply to path in the header and answer via E-mail to: morgana.wbst128@xerox.com )