ttam@cory.Berkeley.EDU (Tony Tam) (05/13/91)
I have an A1000 with the factory 68000 in it and was wordering if there is a 100% working hardware hack to replace it with a 68020 and 68881. What about with a 68010 (direct plug in?). What are the problems/improvements associate with replacing the 68000 with either the 68020/68881 set or the 68010? Also, is there a way to use a IBM CGA (RGB) monitor with the A1000? Thanks Alex Davis ttam@cory.berkeley.edu
drysdale@cbmvax.commodore.com (Scott Drysdale) (05/14/91)
In article <13570@pasteur.Berkeley.EDU> ttam@cory.Berkeley.EDU writes: > > I have an A1000 with the factory 68000 in it and was wordering if >there is a 100% working hardware hack to replace it with a 68020 and 68881. don't know much about this question. >What about with a 68010 (direct plug in?). What are the problems/improvements >associate with replacing the 68000 with either the 68020/68881 set or the >68010? using a 68010 (direct plug in replacement) will get you around 10% improvement overall. integer multiply/divide instructions run around 30% faster, and tight loops (memcpy, strcpy, strlen type things) run 100% faster. > Also, is there a way to use a IBM CGA (RGB) monitor with the A1000? yes, but the results can be unusable. in the amig manual, find the 23-pin video connector pinout. use the DR, DG, DB, and DI pins (and of course the HSYNC, VSYNC, and GROUND pins!). you'll only get 16 colors, and some programs will be unusable because they use foreground and background colors that map to the same RGBI color. > Alex Davis > ttam@cory.berkeley.edu --Scotty -- =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= Scott Drysdale Software Engineer Commodore Amiga Inc. UUCP {allegra|burdvax|rutgers|ihnp4}!cbmvax!drysdale PHONE - yes. "Have you hugged your hog today?" =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
davem@hp-lsd.COS.HP.COM (Dave K. Martin) (05/14/91)
Well, I can't comment on the Lucas/Francis combo (unless someone wants to make a donation to my 1000 upgrade project :-). You can pretty much plug a 68010 in with no problems. Look for MC68010 on Fred Fish 18 for a complete article on how to do so. It also includes the DeciGel software patch to trap illegal instructions. There is a much improved version of DeciGel on FF-454. I ran my A-2000 for a couple of years with a 68010 and the original DeciGel with no problems whatsoever with the exception of one game (which I never got the hang of playing anyway). Most things didn't seem to show much of an speed increase, a few math intensive routines were noticably faster though. Overall, I wouldn't recommend this as a major speedup hack. It is cheap though, about $15.00. The lust for power and speed finally overwhelmed common sense and I went and got a CSA Midgit-Racer. This would work either with my hard drive+controller or with my Microbotics 8-up board but not both. It also seemed to work ok with no expansion boards plugged in. In all cases, the net effect was about a 10-15% slowdown in all tasks. I guess the 7.14mhz 68020 was spending too much of its time pretending to be a 68000 to show any speed increases. The version I was using did not have a FPU chip installed. When I called CSA, they said the Midgit Racer was intended as a floating point accellerator rather than a general system accellerator and were being mis-represented by the sales persons. I was able to trade the Midgit Racer for a 25mhz Mega-Midit-Racer with a 68030 and provisions for 8 meg(more?) of 32 bit memory. So far, I don't have any 32 bit memory on the board but even so, it makes a noticable difference in just about everything that runs. Some things run as much as 1.5 times as fast, especially if I'm unarcing from ram to ram. I expect the speedup to be on the order of 2-2.5 times that of the stock 68000 once I get some 32 bit memory. There are a few demos and games that refuse to work with the 68030 but there are both software and hardware switches to reboot into 68000 mode (the 68000 is removed from its socket, the MMR plugs into it, then the 68000 is plugged into a socket on the MMR). The sum of all of this is that you pretty much get what you pay for. 14 mhz 68000's. Haven't tried one so I can't comment. The 68010 is cheap and the gains are slight. The 68020 I tried resulted in a net slowdown and I had to give up either 6 meg of memory or my hard disk to use it. (Other '020 boards may work just fine). The 68030 in the MMR so far has worked the best, decent speed increases, works with all of my existing software (and hardware :), and should I sell my A-2000, I can put it in my A-1000 (it will also work in an A-500). If you can afford it, go for the Mega-Midgit-Racer. It will work in any 68000 based Amiga. Hope this has been: (A) Helpful, (B) Informative, (C) Interesting, or (D) None of the above. You will be tested at the end of this notes session!
jmt@legend.cma.fr (Jean-Marc Tanzi) (05/14/91)
In article <21528@cbmvax.commodore.com>, drysdale@cbmvax.commodore.com (Scott Drysdale) writes: > using a 68010 (direct plug in replacement) will get you around 10% improvement > overall. integer multiply/divide instructions run around 30% faster, and > tight loops (memcpy, strcpy, strlen type things) run 100% faster. But, correct me if I'm wrong, some programs may hang. The way the 68000 and the 68010 differ is hard to notice, except for the "MOVE FROM SR" instruction, which is protected on the 68010. -- ============================================================================= Jean-Marc Tanzi | Millions of years to make oil and forests, jmt@cma.cma.fr | a century to burn them. Mankind versus Nature: 100000 to 1. | Will Mankind find a tougher planetary opponent?