jac@paul.rutgers.edu (Jonathan A. Chandross) (01/23/89)
Bob Church CS656@OUACCVMB writes: >I just got a Rocket Chip. I had expected a small increase in speed over the >ZIP-CHIP but actually got much more. I don't know the how or why but The RocketChip runs about 25% faster than the Zip Chip. However, it also has a larger cache than the Zip Chip, so it spends less of it's time filling the cache after misses. The RocketChip also caches expansion ROMS, so the 80 column card accesses will be speeded up. > It doesn't quite fit in my //c with zram. The chips a little too high. > Here's my solution, if I can find the part. I would like an "extension > socket". I need a mail 40 pin connector to fit into the 65c02 socket ^-- male > with about six inches of cable and a female socket to plug the rocket > chip into. This is a bad idea. You should never extend chips in this way for several reasons. (1) The first issue is one of the supply of power to the chip. The itty bitty wires in the ribbon cable can cause a voltage drop. This means that the chip can function erratically. This is why the 5 1/4" disk drives have power running over three or four wires. (2) The second, and more important, problem is one of noise isolation. When you see cables being run to disk drives and other peripherals a number of the wires are devoted to being grounds. This tends to cut down on the noise induced on the wires since there is a quick path to ground. With your processor extender, you don't run extra grounds, and the wires will pick up noise, leading to erratic chip function. This is likely to be a big problem because of the amount of stray RF inside the Apple. I don't know what the solution is, but I do not reccomend extension cables. Jonathan A. Chandross ARPA: jac@paul.rutgers.edu UUCP: rutgers!jac@paul.rutgers.edu
DO@cup.portal.com (JEFF SCOTT MARCUS) (01/25/89)
Does anyone know if Rocket or Zip will come out with a 65802 version? I have a 65802 in my IIe, and even with the inticement of so much speed without use of a slot, I would hate to give up my 16 bits and the extra addressing modes. Thanks Jeff Marcus do@cup.portal.com sun!portal!cup.portal.com!do sun.com!cup.portal.com!do