Subject: 4001 MAC CRYSTAL OSCILLATOR SPEEDUPMAC CRYSTAL OSCILLATOR SPEEDUPFirst some disclaimers from PowerPC News: Modifying your Macintosh inany of the ways below will certainly void your machine's warrantee. Inaddition you will be driving your machine's processor faster than Apple designed it to go, and therefore the possibility of long-term damage tothe machine does exist. PowerPC News can not recommend that you modifyyour Macintosh and we are providing this information on an as-is basisand cannot be responsible if the result is a non-functional machine, orindeed a sticky smoking blob in the middle of your desk. The followingfile is republished from the ftp site sumex.stanford.edu where it ismaintained by Marc Schrier and we are not responsible for its content.That had to be said. Nervous enough? Good - now read on.MAC CRYSTAL OSCILLATOR SPEEDUPBy Marc Schrier <schrier@garnet.berkeley.edu> Mac Crystal Oscillator Speedup History 2.3                April 1994 There has been a great deal of interest expressed over the net about these simple and inexpensive Macintosh modifications that yield 20- 40%speed increases.  Over the last year or so I have been doing a  fairamount of crystal oscillator swapping/acceleration on Mac's,  andgathering information from others.  I've made several posts to comp.sys.mac.hardware with the bulk of this info and as new  machinescome out, and new concerns surface, I will try to add them  to thishistory of the modifications, post them on  comp.sys.mac.hardware andmake them available for anonymous ftp  on sumex-aim.stanford.edu in/info-mac/info/hdwr.  Included in this  version is some of the news onthe PowerMac's and Marlin Prowell's  new C650 modification.A little background:All computers operate at a certain frequency with which operations  areperformed.  Within a certain class of computers, for example  Mac's witha 68030 processor, the higher the frequency, the higher  frequency ofoperations processed, and the faster the computer  provided there is noother speed effecting hardware like a cache or  slow data path.  Thedesigner of the computer, Apple in this case, will use components thatare rated at the same frequency or faster  than the final computer willbe.  The 68030's are made by Motorola.   All 68030's are generally alikein what they do, but they are not  alike in how fast they can do it. Motorola sells several 68030  processors rated at 16, 20, 25, 33, 40 and50MHz for Mac's,  accelerators and such.  A large frequency differencewill require a  different mask during production of the processor, butsmall changes  may not.  Motorola only needs to guarantee that the chipthey mark  as 20MHz will function properly at 20MHz under a variety of conditions.  Some chip vendors will test parts at different  frequenciesand sort the chips accordingly while others may just  label the them atwill and sell the chips at the different price as  long as they arewithin spec.  So it is possible that the 20 and 25's  actually come fromthe same batch, are separated on demand, and  tested to make sure theywill withstand that frequency.  Because of  this, it is possible that a20MHz processor will function fine at a  higher frequency, say 25MHz. Running it faster will however  generate more heat.  Many of the components in the computer need to be synchronized, so  afrequency is generated by a crystal oscillator to synchronize them.  Other parts like NuBus cards and video do not have to be the same frequency, so they may have separate crystal oscillators.  A typical computer may have several crystal oscillators to clock different  groupsof components on the motherboard.  Provided the components  that areclocked by a particular crystal oscillator are capable of a  speedincrease, that crystal oscillator may be replaced with one of a  higherfrequency.  How much a specific Mac can be sped up by this  methoddepends on how the motherboard was designed, the  components used, andwhat things the crystal oscillator that  controls the processor alsocontrols.  With some of the newer Mac's,  there are a few MHzdifferences in the top speeds reported for the  same model, so part ofthis is luck of the draw. This crystal oscillator swapping has been done for years, and some early computers even had jumpers that made it really easy to  disableone oscillator and enable another higher frequency one.  The  firstMac's to be modified were the IIsi's.  A stock IIsi's runs at  20MHz,and IIci's at 25MHz, and since the architecture of these  machines wasso similar it seemed reasonable to run a IIsi at IIci  speeds.  Anotherimportant factor was that earlier Mac's had just  one crystal oscillatorthat controlled everything, and if you replaced  it you would messthings up.  The IIsi was different as some noted  through its frequencydeviation from its 8 and 16MHz precursors  where the main frequency washalved and quartered to run the CPU,  serial ports, video...  The IIsiwas different, it had 4 crystal  oscillators, only one of whichcontrolled the processor speed. The Crystal Oscillator:The type of crystal oscillator in the early Mac's is a full size, 14 pin package, TTL type crystal oscillator.  It is a rectangular metal can, with approximate dimensions of 2.0 x 1.3cm and typically about 0.3-0.6cm high.  All crystal oscillators have 4 pins.  Some are numbered 1,2,3,4 and others 1,7,8,14.  Pin 1 is always the pin next to the pointed edge (the others are rounded), with the dot, or next to the indentation on the newer CMOS, or surface mount crystal oscillators.  With the pins facing down, put the dot, or indentation to your left, and the pin on the left, closest to you is pin 1.  Going counter clockwise, pin 2 (or 7, depending on what numbering scheme) is to  theright, Pin 3(8) right side and further away, and 4(14) left side,  andfurther away.  Pin 1 on all the newer Mac's with surface mount  crystaloscillators, and some of the older ones is an output  enable/disable pin(OE).  On some of the crystal oscillators you  purchase Pin 1 will beOE, yet on many it will not be used (no  contact (NC)).  It is notimportant which you get as you will not be  using the output enablefeature.  Pin 2(7) is a ground.  Pin 3(8) is the  output.  Pin 4(14) isthe supply voltage, +5 VDC.  I've checked a few  of the older typeMac's, and the oscillator on Mac Plus's is not OE,  while the ones onthe IIsi's and Quadra 700's are OE.  I'm not sure  why Apple uses thesetype of oscillators instead of the ones where  pin 1 is not used.  Iguess it is possible that something on the circuit  board can ground pin1 and stop or restart the computer.  If anyone  knows, please let meknow.  Printed on the crystal oscillator will be  its manufacturer, partnumbers, and frequency.  On these early Mac's,  the processor runs athalf the speed of the oscillator, so a 20MHz  Mac IIsi has a 40MHzcrystal oscillator.  There are several different modification techniques.  They will all give you the same final max speed.  Some are just easier or more elegant than others.  As with all these modifications, even though there may be no visible sign that you modified your Mac, you have voided the warranty on the Mac.  As Apple states: "This warranty does not apply if the product has been damaged by accident, abuse, misuse, or misapplication; if the product has been modified without the written permission of Apple; or if any Apple serial number has been removed or defaced."This is what I seem to be finding.  These numbers vary from Mac to  Mac,so these are just averages.  Some machines will go faster than  this. These are the oscillators that Output Enablers ships in their  kits.Modifications:Machine   Mod-1   Mod-2   Mod-3   Oscillator/speed   FinalOscillator/speedIIsi      yes     yes     no      40/20              55/27.5MHzC610      yes     no      yes     10/20              14-14.31818/28.6MHzC650      yes     no      yes     12.5/25            14.31818-14.75/29.5MHzC650-mod  yes     no      yes     12.5/25            20/40MHzC660av    yes     no      yes     12.5/25            16-17.496/35MHzQ610      yes     no      yes     12.5/25            15-15.288/30.6MHzQ650      yes     no      yes     16.6667/33.3       21-22/44MHzQ660av    yes     no      yes     12.5/25            16-17.496/35MHzQ700      yes     yes     no      50/25              70/35MHzQ800      yes     no      yes     16.6667/33.3       20-21/42MHzQ840av    yes     no      yes     20/40              23.247-24/48MHzQ900      yes     yes     no      50/25              70/35MHzQ950      yes     yes     no      66/33              ?75-80/?40MHzPM6100    yes     no      yes     30/60              40/80MHzPM7100    yes     no      yes     33/66              ?45/?90MHzPM8100    yes     no      yes     40/80              ?50/?100MHzMod-1The basic idea of Modification #1 is removing the onboard oscillator, and replacing it with a faster one.  This is the mod most people use  onthe IIsi, Q700, Q900, & Q950.The basic procedure used is that you have to unsolder the TTL  crystaloscillator from the motherboard on the Mac, and put in a new  one. Instead of putting one straight onto the board, it is nice to use  asocket so you can test your individual Mac, and see what the cutoff frequency is, and you can always put the original oscillator back in the socket.First find the crystal oscillator by referring to the previous table and description of physical characteristics.  Be careful when you remove the oscillator.  Most people just use a normal soldering iron, and are fine; a grounded (three prong soldering iron) would be a bit safer.  They just use copper wick to soak up the solder from all four pins, and pop out the proper oscillator.  Because the boards are multilayer, be careful not to damage anything; be gentle.  There was recently one report of a guy who damaged his IIsi board doing this.  But that was the only incident I had ever heard of, and lots and lots of people have done this.  I use a "desoldering iron".  They melt the solder, and have a pump to suck out the solder while you swirl the  pinfrom the oscillator around to get all the solder out.  After you  havedone all 4, if you have done a good job, the oscillator just pops  out. If you have access to one of these desoldering irons, I highly  suggestyou use it as it does a cleaner job, and there is less risk of  burning(discoloring) the board.  Next, take a 14 pin IC socket,  remove all thepins but 1,7,8, and 14, and solder it into the board  (see Modification#3 for a Digi-key part number).  Make sure you put  it in so pin 1 willgo into pin 1, 2-2, 3-3, 4-4.  And the notch in the  socket should facethe same way the dot on the old oscillator was  facing.  Now just put ina faster oscillator.I have done this to a few IIsi, and the highest frequency we could get to work without problems was 27.5MHz.  Thus a speed increase from  20 to27.5MHz.  The actual crystal is 55MHz (double the frequency).   TTL55MHz crystal oscillators do exist, but they are rare.  The thing  mostpeople seem to do is get a CMOS oscillator, and they work just  fine. Digi-Key sells a 55MHz CMOS crystal oscillator in a 14 pin  package,part# SE1509.  At 58.9 and above, there are problems with  the floppydrive; you cannot boot the Mac from a floppy, but other  than that it isfine until just over 30MHz.  I recently had a IIsi at  28.3MHz and itwas fine.  Be warned that some cards may not work  after thismodification.  Most will work at 25MHz, but will not at  27.5MHz, sojust stick with 25MHz if that is the case. The IIsi does not come with a heatsink, so to reduce the heat in the processor, get a small heat sink to attach to the 68030 to cool it down; any heat sink will do; the more surface area the faster heat  willbe dissipated.  Be careful when you put on the heat sink.   Typicallyyou'll use some heat transfer grease, but the heat sink can  slide offif the Mac is moved, and the heat sink might short  something out.  Thebest thing seems to be to get a heat sink with a  hole in the middle, ordrill one yourself, use the heat transfer  grease, but also put a smalldrop of super glue through the hole in  the heat sink onto the chip orput a drop on the side, and this should  hold it in place.  Fry's sellsnice heat sink/fan combo's.  They run $10  and up, and I think they aremore than you need, but it should keep  the processor cooler.  I believethey come with a Y cable to tap into  your hard drive power cable topower the fan.  A more complete FAQ  on this modification for a IIsi isavailable via anonymous ftp from  sumex.stanford.edu ininfo-mac/info/hdwr (iisi-25mhz-upgrade- faq.txt).For the Quadra 700 and 900, you can get 70MHz TTL crystals from  Fry's. The 70MHz may not work, and you may have to back down to  66.6666MHz,the next most common frequency, Digi-Key part#  CTX137.  The Q700, Q900,and Q950 come with a heatsink installed.   A more complete file on thismodification for a Quadra 700 is also  available via anonymous ftp fromsumex.stanford.edu in info- mac/info/hdwr(quadra-700-clock-mod-145.txt).It has been reported for, but I have not yet done a Q950, but the general idea is the same.  If anyone has any more info on doing a  Q950,please e-mail me and I'll add it.Mod-2The basic idea of Modification #2 is to disable the onboard  oscillatorwith a jumper and feed in a new signal on the back of the  board.  Thereare very few who have performed this mod, but I feel it  is more elegantand safer since you don't have to remove the onboard  oscillator.  Thisnewer, and less evasive method has been performed  on IIsi's & Q700's bymyself, and should work fine on the Q900 &  Q950.The most difficult and risky part of "Mod-1" above is the removal of the oscillator, and this is an alternative procedure that gets around that since the crystal oscillators Apple uses have pin 1 as OE.  On a crystal oscillator with pin 1 as OE, if you ground pin 1, you disable the output from pin 3(8), and you can feed a new signal into pin 3(8) without removing the original crystal oscillator. Several months ago Iperformed this modification on a Quadra 700 by  tacking (soldering) ajumper on the back of the motherboard between  pins 1 and 2(7) of the50MHz oscillator, and ran wires about 8 inches  long each from pins2(7), 3(8), and 4(14) to a 14 pin socket attached  to the inside of theQ700 with pins in positions 7, 8, and 14.  Into  this we placed a 70MHzcrystal oscillator and the Mac ran fine at  35MHz and is still doingfine.  This modification is nice in that it is  a bit less risky as faras damage to the motherboard, but you have to  be careful to use thinwires in order to make clean solder joints.   With this modification youcould remove the wires at a later date to  return to the originalconfiguration more cleanly.  I cannot say for  sure if this will work ona Q900 or Q950 until I put one of those  crystals on a scope, oractually try the modification, but am pretty  sure it will.  If anyonehas removed a crystal from a Q900 or Q950  and still has it, I'd be gladto check it out and send it back to you. Mod-3The basic idea of modification #3 is building a clip that disables the onboard oscillator, and feeds in a new, faster signal.  The beauty of this modification over the others is that you do not have to do any soldering on the motherboard itself, just on the part you clip onto  thesurface mount crystal oscillator in your Mac.  This is the  modificationmost people use on the C610, C650, C660av, Q610,  Q650, Q660av, Q800,Q840av, PM6100, PM7100, PM8100. The really neat thing about this came into play in February 1992  whenApple released the Centris 610, 650, and Quadra 800.  In these  machinesand since, Apple has been using surface mount crystal  oscillators.  Nowthat Apple was using surface mount crystal  oscillators, there wasplenty of accessible area on the metal tabs of  the oscillator.  In June'93 Guy Kuo reported the first crystal swap  of sorts on a Centris 610to the net.  He soldered pins 3, 5, 10, and  12 of a 14 pin socketdirectly onto the surface mount crystal  oscillator.  Because the pinson a TTL type crystal oscillator are at  positions 1, 7, 8, and 14, hemade jumpers between pins 5-7, 8-10,  and 12-14.  He disabled theon-board surface mount crystal  oscillator with a jumper between 3-5. Then put the new crystal in  the socket.  This file is also available onSUMEX in info- mac/info/hdwr (centris-610-clock-mod-11).I was a little hesitant about soldering onto my new Quadra 800, so wrote to him a few days later about using a surface mount test clip, and asked his thoughts.  He suspected I could not find a reasonable test clip, but otherwise believed it would work.  A few days later  the3M surface mount test clip arrived, and the test clip worked  perfectly. I was running my Quadra 800 at 40MHz, with no problems,  and best of allthe modification was all contained in a simple little  clip that couldbe removed without trace at will.  And thus the  removable test clipapproach was born.  My Q800 even worked at  48MHz as long as I did notaccess the serial ports.  A few days later  I got several crystals, andfound the highest frequency on my Quadra  800 to be 42.0MHz.  Since thenI've tried it at 42.106MHz, and the  serial ports did not work, so thecutoff for my Q800 was at 42.0MHz.   If you never use your serial ports,48MHz worked fine for me, while  at 50MHz my Mac was not happy and wouldnot boot.   So if you are still interested, you will need a surface mount test clip; 3M and Pomona make them, and I prefer the 3M ones.  Make sure  youget a surface mount test clip.  The I.C. test clips also work, but I prefer the surface mount SOIC (small outline integrated circuit)  ones. A 10, 12, 14, 16, or 18 pin clip will be fine.  I'd say go with a  14 or16 narrow or wide.14 pin, part# 923650-14-ND  $6.5816 pin, part# 923650-16-ND  $6.96These are the part numbers for the ones with alloy leads; I used to recommend the gold coated ones, but the resistance/corrosion effect  isminimal.You will also need a 14 pin IC socket, there are plenty of types.  The machined pin ones are nice because you can pop out the pins that are not needed to get them out of the way since you only need three pins  inthe socket. 14 pin IC socket w/tin pins, part# ED3114  $0.57 You will also need an oscillator (more on this later), a little wire, soldering iron, solder, and possibly heat sink depending on the machine.  For a C610, C660av, Q610, and Q660av you should add a  heatsink, HS160-ND is the 0.600 inch one, and is plenty ($3.98). The others already have heat sinks, and do not get too hot.  I had an extra fan with my Q800, but removed it, and it has been fine.  The  heatsinks come with the clips needed to attach them to the chip.   These area bit of a pain, you just have to work at it for a while.   There may beseveral ways to do it, but I just slide the clips on from  the side. Sometimes they fall off half way there, but eventually it  works.  Somepeople have been using the heat sink/fan combo's.  I  have not, but theyseem to work fine as well.  The new Q610 and  Q660av computers are basedon a new mask of the 68040 that comes  at 25MHz without a heatsink(There is an "H" after the '040 and  before the "RC").  This is the samemask as the C660av and Q840av  uses.  If you do the modification on themit would be best to add a  heat sink.How to put it all together:Stand the clip so it's jaws are facing down, and the rows of pins go >From left to right, and call the closer row A and the further row B.  Number the pins from left to right 1 through 7 (for the 14 pin clip).  Next place the IC socket with the pins down, and the notch to the  left,and number the pins as 1, 2, 3, 4, 5, 6, 7 in the row closest to  you,going left to right.  The other row is numbered 8, 9, 10, 11, 12,  13,14 as you go right to left (back towards the notch). Now starting withthe test clip, leave pins in positions A2, A6, B2,  and B6.  Next soldera little jumper wire between pins A2 and A6.   Now get the 14 pin ICsocket, and remove all the pins but 7, 8, and  14.  Solder a jumper wirefrom pin 7 on the IC socket to the  jumpered pins on the clip, either A2or A6.  Also solder a jumper  wire from pin 8 to pin B6, and pin 14 topin B2. If you get the narrow clip, you may want to replace the springwith  one with less tension; they are like $0.30 at hardware stores, andI  cut them into two springs.  This way you don't have to push so hard, and it is easier to position on the motherboard.  Now put the crystal in the socket with pin 1 in 1, 2 in 2, 3 in 3 and 4 in 4. There are several surface mount oscillators used on the  motherboards. The proper surface mount crystal oscillator on the  mother board willhave a frequency on it half that of your computer  and can be determinedfrom the above list.That is it, now you just clamp it onto the surface mount crystal oscillator with the notch on the socket facing the same way as the surface mount crystal oscillator.  And watch to make sure the little pins clamp onto the surface mount chip.  You may want to use a flashlight for this.  These clips hang on very, very well, I've never had mine move in the last 9 months, nor any of the other ones I've done.Centris 610 Ethernet Problems:Those Centris 610's that have ethernet capability share the 10MHz oscillator with the CPU.  If you replace that oscillator with a different one, your ethernet will no longer work.  In January, Eckart Hasselbrink (Hasselbrink@fhi-berlin.mpg.de) posted a fairly simple hardware modification to fix this to comp.sys.mac.hardware.  So if  youplan to use you ethernet on your Centris 650 and speed it up, you  willneed to perform Eckart's modification first. PowerMac's:I have only done PM6100's, and it works fine at 80MHz.  At 86MHz it overheats quite rapidly.  With a cool hairdryer cooling the heatsink  onthe 601, it worked fine, but was a bit noisy :-).  See the table to  seewhich oscillator you will need to clip onto.  This mod should  work justfine on the 7100 and 8100 computers as well.  On the  8100 the powersupply may be in the way of the clip.  If anyone in  the Bay Area has aPM7100 or PM8100 and wants to try it, drop me a  line and we can give ita spin.  Or if anyone tries it, please let me  know how it goes so I canadd it to this file and pass it on to others  who ask.  The guesses onthe chart about what oscillator to use for  the PM7100 and PM8100 arejust that, guesses.On most of these newer machines, the problem is with the serial  ports,but the speed of the memory is also important, so if you plan  to boostyour Mac very far, you may need faster SIMM's. To test out the modification, the best thing to do is just use it a while.  You can run Speedometer 3.23 (available at SUMEX in info-mac/cfg) to see the changes.  I use Snooper with the serial port loopback plugs to check the serial ports to find their limits; Snooper also tells you what frequency you are running at in round numbers.  Snooper was made by Maxa, and I am told Snooper is currently owned  byCentral Point Software.  The current version of MacCheck is 1.0.5 (available on bric-a-brac.apple.com), and it now properly reports the computer frequency.If your Mac does not give the standard chime at startup it means  yourclip is only half on.  It is disabling the surface mount  oscillator,but not replacing it.  Just remove the clip, reposition, and  try again.Special C650 Mod:Using the above clips, the max frequency for a Centris 650 is about 30MHz before you encounter serial port problems.  Marlin Prowell (mbp@janus.com) following up on a hunch by James McPhail (jmacphai@cue.bc.ca) looked into the differences between the C650  andQ800 motherboards in hopes that a simple modification might  enable theserial ports to function properly at 33MHz (Q800 normal  frequency) orhigher.  On the bottom of the motherboard, under the  IOSB chip, Marlinfound two differences.  R151 is installed on the  C650's, and is missingon the Q800's.  R152 is missing on the C650's,  and is installed on theQ800.  R151 is a 300 ohms resistor and R152  is a 1.2k ohm resistor. Looking at the bottom of the board, with the  back away from you, R151is 3 3/4" from the right, and 3" down.  The  tabs for R152 are 4" fromthe right, and 3" down.  R151 is black, and  says 301 on it.Marlin felt that R151 was glued to the board, and just using solder braid he was unable to remove the resistor for fear that prying it off may damage the traces that run under it.  Heating the resistor with a soldering iron Marlin was eventually able to soften the glue and  removethe resistor.  Or you can use James McPhail's two soldering  ironWestern technique with a soldering iron in each hand to heat  each sidesimultaneously and flip the resistor off the board.  Now  just add theR152.  Marlin suggests holding the surface mount  resistor in place witha small screwdriver while soldering it to the  exposed pads on theboard.Marlin has since used both the serial and modem ports error free  whilerunning his C650 at 40MHz, and MacCheck reports no problems.   He hasalso checked to make sure the ethernet works, and it does.   SinceMarlin's initial modification, it has been confirmed by at least  threepeople.  On some of these Mac's the CPU overheats after a  while, soMarlin suggests you add a fan to dissipate the heat faster  >From theheatsink.  You can also just run a bit slower, say 38MHz.   You canpurchase these 1.2k resistors from Digi-Key, but the  minimum order is200 of them.  If you e-mail your address to Output  Enablers atoe@well.sf.ca.us, they will send you a free resistor left  over fromMarlin's extra 199.****This modification makes your Mac think it has become a Quadra  650,and the Quadra 650 did not exist when most of you purchased  yourCentris 650.  The System Enabler 040 that came with your  Centris 650,version 1.0, will not work after this modification, and  your Mac willnot start up unless you have already updated the  System Enabler 040 toversion 1.1, the current version.  The System  Enabler 040 version 1.1is available from your local Apple Dealer, or  you can ftp it frombric-a-brac.apple.com.  Marlin suggests you also  put the new enabler onall your recovery utility disks as well so you  will be prepared nexttime something goes wrong.**** Recently a few companies have been started that replace the crystal oscillator in powerbooks to speed them up, and add a 68882.  I have some ideas on how to do this, and the precautions to make.  Has  anyonedone it themselves?  I have some info from Virgil Mehalek (vm@christa.unh.edu) who noted the differences between the 140 and  170. I'm not going to add that info until it has been attempted, but  ifanyone is interested in a copy of that info I can forward it to you.  One important addition thanks to Virgil, worth noting now is that Active Electronics (800) 228-4836 sells the 33MHz MC68882-FN33A  for$76.95 plus S&H.Address' for some other parts suppliers:Fry's Electronics340 Portage AvePalo Alto, CA(415) 496-6000Digi-Key(800) 344-4539Output Enablers1678 Shattuck Ave.  Suite # 247Berkeley, CA 94709oe@well.sf.ca.usThere are currently two companies that sell already made clip-on  kitsfor the Mac's with surface mount crystal oscillators. KS Labs6326 E. Livingston Ave, Suite 131Reynoldsburg, OH 43068$165/kitOutput Enablers1678 Shattuck Ave.  Suite # 247Berkeley, CA 94709oe@well.sf.ca.us$50/kitIf you have gotten any of these new machines to work, please let me know.  Or if you have any questions or comments that should be  added tothis, feel free to e-mail me as well.                                           Marc Schrier                                           schrier@garnet.berkeley.edu