Ok... I've spent the better part of wed night with the 610p, the logic analyser and SoftICE and VistaScan from the UMAX webpage.
This looks like this may be a tricky RE job as I haven't found the magic. Pieces of the puzzle that make everything make sense. Here's what I've learned: First in order to get valid data under VistaScan I have to have my parallel port set to _either_ SPP or ECP+EPP. Strictly EPP does _not_ work. If set to EPP the scanner performs all scan functions but the data that shows up in the preview windows is scrambled. Perhaps its using the compression feature built into the ECP? Dunno how it works in SPP mode though. Attempting to start out simple I tried to log the IO from a simple application called powersave which just turn on and off the scanner light. This app works regardless of what mode the parallel port is in. My thought was that I would set up the LA to trigger on the various transfer modes and find the one that matches. I ran into the problem though that the data I see on the logic analyser dosen't seem to match any of the timeing diagrams I have for any of the modes. At least not for any of the modes listed in Jan Axelson's Parallel Port Complete. I can't seem to figure out the exact clocking scheme that will let me grab the data on the wire. Of course it could have just been that it was 3am... So I began useing SoftICE to try and get a better understanding of what it was doing. SoftICE isn't the greatest thing for logging port IO. It (at least my version) won't let me breakpoint on a rage of IO so I have to specifically choose a port address to watch for. The powersave app though appears to have 2 subroutines that do all the IO so I was able to break on thier addresses and extract the port address and data from each transfer. But its really tedious. And I think that since I breakpoint on every IO attempt that the transfer is timeing out causing it to repeat as the code appeared to get stuck in a loop that would drop out after 10 attempts. I quit about that time. See the end of the message for the listing. So I got some data but by the time I was done it was really late and I have not had a chance to study it. Hopefully somebody can make some sense of this and give me a boost. I think my next step is to set up a windows NT machine and use portmon from sysinternals to grab the IO. Portmon's webpage claims to be able to log all parallel IO under NT. Vistascan is listed to run under NT. On w98 portmon dosen't see any parallel activity I'm guessing because the app is doing direct reads and writes rather than calling an api call. Heres the log: Key: -> means write to port. <- means input from port. side text describes what the next instructions did with the input data at least up until it jumped away. Program boots.. Then it does lots of IO's to various parallel port base IO addresses... You don't have to set the IO base in the app anywhere so this must be how it finds the scanner. My base address is 0x378. All number are in hex. 40 -> 378 06 <- 37a 3f <- 379 Mask with 78 look for 38 07 -> 37a 3f <- 379 Mask 78 look for f8 04 -> 37a ff <- 379 Mask f8 look for f8 05 -> 379 c5 <- 37a Mask 0f look for 05 04 -> 37a cf <- 379 Look for bit 5 to be 0 c4 <- 37a Mask 5f assign result to V1. V1 = 44 V1 (44) -> 37a 55 -> 37c cf <- 379 Look for bit 5 to be 0 c4 <- 37a Mask with 5f assign to V2 V2 = 44 V2 (44) -> 37a aa -> 37c c4 <- 37a OR with a0 assign to V3 V3=e4 V3 (e4) -> 37a cf <- 379 Look for bit 3 to be 0 The last test fails and it looks like it will attempt to try this 10 times before jumping ou t of the loop. Thats it for now... I'll try to get the NT logs this weekend. -- Richard A. Smith Bitworks, Inc. rsm...@bitworks.com 479.846.5777 x104 Sr. Design Engineer http://www.bitworks.com
