Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!csd4.milw.wisc.edu!bionet!agate!web-2a.berkeley.edu!c60a-1fy From: c60a-1fy@web-2a.berkeley.edu (Anon) Newsgroups: comp.sys.amiga Subject: Re: Lucas Accelerator Summary: SUCCESS working with Starboard!!! Message-ID: <19666@agate.BERKELEY.EDU> Date: 29 Jan 89 23:38:57 GMT References: <6731@louie.udel.EDU> <819@faui10.informatik.uni-erlangen.de> <602@boing.UUCP> <1989Jan26.210550.10129@gpu.utcs.toronto.edu> Sender: usenet@agate.BERKELEY.EDU Lines: 87 !!!!!!!! Finally, after 2 weeks of solid fiddling, I have successfully gotten my starboard/stardrive to work reliably with my Lucas board. I tried many different methods, but the only thing that worked was to build the bus terminator Brad posted, but modify it in a minor way. After first building the terminator I was able to get the workbench prompt to come up, but the machine would crash when I put in a disk or sometime in the middle of the startup-sequence. Games with long boot sequences were especially succeptible. Looking at the signals on the terminator with an oscilloscope allowed me to fix the problem. WHAT TO DO (or at least try if you're stuck) When assembling your parts, get 14, 16, 18, and 20 Mhz crystals. Some values for U9 won't work with a fast clock, others NEED one. Play around with U8, U9 and the crystal to get the best combination (get the farthest). Build the bus terminator, which, if you've been missing, consists of 4.7k pullups and 1k's with .001uF caps to ground on the data lines and 4 control lines. Don't solder your parts on the board, though, but instead use SOCKETED sips. When buying the sips, get 2.2 and 3.3k sips too. ******* This is it ****** If this works, great! If not, replace the 1k to ground on /AS with a 10k trimmer. This is what worked for me. The signal was suppressed when I saw it on the scope using a 1k resistor. My trimmer is set to about 3.7k but you might have to play around with it. Try again. You should be able to find a U9/U8/Crystal/Pot setting which works fairly well. Replacing the 4.7k pull ups with 3.3 or 2.2k values may help stabilize things. Good Luck. Here's my set-up as a starting point. I think I've mentioned all which seemed to fix the problem, but maybe something I did earlier was necessary in the final solution. LUCAS Board with 16 Mhz 020, 12 Mhz 881 Microbotics starboard with stardrive controller. 74ACT244 removed from the starboard and replaced with an LS part (cuz I needed an ACT part for the 68000 hack and couldn't find one) Beforementioned 68000 hack keeping the 68000 on the bus. Pal Upgrade kit. Ground wire from lucas board to amiga Metal springs placed between starboard and amiga to securely ground case 16Mhz Crystal 74LS74 for U8 74ALS74 for U9 CLOCK ON STARDRIVE Everything works except the Startime software. (works in 68000 mode) Apparently the software uses timing loops when accessing the clock, and even with the cache off it runs too fast (comes back immediately) to set/read the date/time correctly. FLAME HIGH I called Microbotics, and got no help at all. First, it took 20 minutes long distance for me to convince the guy that I was not having noise problems on the bus, and that my Lucas board was working fine. During our conversation, the guy repeatedly said (4-5 times), as if he were reading: "Microbotics designs its products to work with a base Amiga. We have no intention of modifying our product to work with a non-standard configuration" <--- !!!!! While I can see the position they are in, what do they call non-standard! How about we who want expansion RAM and, dare I dream, a hard disk?!!! They guy on the other end insisted that the clock not working was the lucas board's fault for being poorly designed! Well, I suppose if it were designed to provide no speedup at all, then yes, the clock probably would work, but I don't thing that's acceptable! For that matter, the Lucas board works just great on a "base" amiga too! In summary, don't call Microbotics for help. Also, before buying anything else from them, think twice and remember their "compatibility" policy--base machines need only apply. [In all fairness, I have called Microbotics on 2 previous occasions and got friendly, helpfull advice, so maybe it was only that this guy was a simple A****le.] -Vince Lee (posted by friend, so please don't mail him)