Date: Wed, 19 Jan 94 01:20:24 PST From: Marc Schrier Subject: [*] Mac_Crystal_Oscillator_Speedup_History_2.1 Resent-To: macgifts@sumex-aim.stanford.edu Mac Crystal Oscillator Speedup History 2.1 Over the last year or so I have been doing a fair amount of crystal oscillator swapping/acceleration on Mac's, and gathering information from others. Several people have expressed an interest in what I've learned. I've made several posts to comp.sys.mac.hardware with the bulk of that info. As new machines come out, and new concerns surface, I will try to add them to this history of the modifications and post them on comp.sys.mac.hardware and on SUMEX-AIM.STANFORD.EDU for anonymous FTP. All computers operate at a certain frequency. Within a certain class of computers, for example ones with a 68030 processor, the higher the frequency, the higher frequency of operations processed, and the faster the computer. The seller of the computer, Apple in this case, will use components that are rated at the same frequency or faster than the final computer will be. A 68030@20MHz is the same as a 68030@25MHz, but the 25MHz version has been designed in such a way that when run at 25MHz everything will function properly. If you run the 20MHz version at 25MHz the component will be hotter than at 20MHz, and may fail. Thanks to a note of clarification from Jinfu Chen, "apparently the semiconductor vendors don't design different masks for chips running at small frequency range, say 20MHz-25MHz, although bringing up a 16MHz '030 to 50MHz '030 would certainly involve redesign. A simple answer to why a 20MHz '030 can be run at 25MHz is the design margin. When a microprocessor is spec'ed at X MHz, it simply means the manufacture will guarantee it function at that frequency and in fact it could run much faster. Some chip vendors will test parts at different frequencies and sort the chips accordingly. Others may just label the them at will and sell the chips at different price as long as they are within spec. This practice is actually cheaper to the manufacture." So the chip they label as 20MHz may function properly at 25MHz or higher under the proper conditions. All of these components in a computer are clocked by a crystal oscillator. A typical computer may have several crystal oscillators to clock different components and some crystal oscillators may run several unrelated components on the motherboard. Provided the components that are clocked by a particular crystal oscillator are capable of a speed increase, that crystal oscillator may be replaced. How much a particular machine can be sped up depends on that particular machine. With some of the newer Mac's, there are a few MHz differences in the top speeds reported. This crystal oscillator swapping was initially done on PC's, and then later on Mac's. The first Mac's were the IIsi's since their architecture was so similar to the IIci it seemed reasonable to run them at IIci speeds. A stock IIsi runs at 20MHz, and a IIci at 25MHz. Of course this will void the warranty, but many people find the 20-40% speed increase worth it. The type of crystal oscillator used in the early Mac's is a full size, 14pin package, TTL type crystal oscillator. It is a rectangular metal can, with approximate dimensions of 2.0 x 1.3cm and typically about 0.5cm 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 (CMOS, or surface mount crystal). 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. Pin 2 (or 7, depending on what numbering scheme) is to the right, Pin 3(8) right and further away, and 4(14)left, and further away. Pin 1 on all the newer Mac's with surface mount crystal oscillators is an output enable/disable pin (OE). On some of the crystal oscillators you purchase Pin 1 will be OE, yet on most it will not be used (no contact (NC)). Pin 2(7) is a ground. Pin 3(8) is the output. Pin 4(14) is the supply voltage, +5 VDC. I've checked a few of the older type Mac's, and the oscillator on Mac Plus's is not OE, while the ones on the IIsi's and Quadra 700's are OE. Printed on the crystal oscillator will be its manufacturer, part numbers, and frequency. On these early Mac's, the processor runs at half the speed of the oscillator, so a 20MHz Mac IIsi has a 40MHz crystal oscillator. For the IIsi, Quadra 700, 900, and 950 the modification procedure is all the same. This procedure would be the same for a 128, 512, Plus, SE, Classic, Classic II, Color Classic, II, IIx, IIfx, LC, LCII, LCIII, and IIvx (did I name them all), but I have not heard of anyone doing the modification on these machines yet. I have heard reports of the modification on a SE/30, IIcx, and IIci, but these people were not able to get significant speed increases and ran into timing and video problems. If you have any more info on any of these Mac's, please e- mail me. The basic procedure used is that you have to unsolder the TTL crystal oscillator 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 a socket so you can test your individual Mac, and see what the cutoff is, and you can always put the original oscillator back in the socket. 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 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. I use a "desoldering iron". They melt the solder, and have a pump to suck out the solder while you swirl the pin from the oscillator around to get all the solder out. After you have done all 4, if you have done a good job, the oscillator just pops out. If you have access to one of these, I highly suggest you use it as it does a cleaner job, and there is less risk of burning the board. Next, take a 14 pin IC socket, remove all the pins but 1,7,8, and 14, and solder it into the board. Make sure you put it in so pin 1 will go into pin 1, 2-2, 3-3, 4-4. And the notch in the socket should face the same way the dot on the old oscillator was facing. I have done this to a few IIsi, and the highest frequency we could get to work with out problems was 27.5MHz. Thus a speed increase from 20 to 27.5MHz. The actual crystal is 55MHz i.e. double the frequency. TTL 55MHz crystal oscillators do exist, but are rare though. The thing most people 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 floppy drive; you cannot boot the Mac from a floppy. Recently I have heard of IIsi's running fine at 28.2MHz. 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 will be dissipated. Be careful when you put on the heat sink. Typically you'll use some heat transfer grease, but the heat sink can slide off if the mac is moved, and the heat sink might short something out. The best thing seems to be to get a heat sink with a hole in the middle, or drill one yourself, use the heat transfer grease, but also put a small drop of super glue through the hole in the heat sink onto the chip or put a drop on the side, and this should hold it in place. Fry's sells nice heat sink/fan combo's. I'm not sure what they cost, and I think they are more than you need, but it should keep the processor cooler. I happen to have a JAMECO catalog next to me, and they sell these as well. Heatsink/fan for 80486 CPU, part# 67660. These are 1.75"L X 1.88"W X 0.75"H. I'm guessing these will fit fine, but I have not tried one. And then you need a Y cable to tap into your hard drive power cable to power the fan and your hard drive (Fry's has them, and some kits may come with one). A more complete FAQ on this modification for a IIsi is available via anonymous ftp from sumex.stanford.edu (iisi-25mhz-upgrade-faq.txt). For the Quadra 700, 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. It has been reported for, but I have not yet done a Q900 or Q950, but the general idea is the same. On a crystal oscillator with pin 1 as OE, if you ground pin 1, you disable the output from pin 3(8). I'm not sure why Apple uses these type of oscillators instead of the ones where pin 1 is not used. I guess it is possible that something on the circuit board can ground pin 1 and stop the computer from working. Maybe it is part of restart? I don't know, but I'll try to find a board to look at it and see if it is even used. If anyone knows, please let me know. Since some of the crystal oscillators Apple uses have pin 1 as OE, if you short pins 1 and 2(7) it disables the output from pin 3(8). From the Mac's I've looked at recently, it does not appear that there is enough room on the back of a board to put in a socket as I suggested in the last post. Since the IIsi's and Quadra 700's use OE oscillators, you can however still take advantage of this. The most difficult and risky part of the classical procedure above is the removal of the oscillator, and this gets around that. This last weekend we performed this new procedure on a Quadra 700 by soldering a jumper on the back of the motherboard between pins 1 and 2(7), and ran wires about 8 inches long each from pins 2(7), 3(8), and 4(14) to a 14 pin socket with pins in positions 7, 8, and 14. Into this we placed a 70MHz crystal oscillator and the Mac ran fine at 35MHz and is still doing fine. This modification is nice in that it is a bit less risky as far as damage to the motherboard, but you have to be careful to use thin wire to make clean solder joints. And you could remove the wires at a later date to return to the original configuration. This will work on Quadra 700's and IIsi's, and would probably work on other Mac's with TTL oscillators, but I cannot say for sure until I put one of those crystals on a scope, or actually try the modification. If anyone has removed a crystal from another Mac and still has it, I'd be glad to check it out and send it back to you. The really neat thing about this came into play in February 1992 when Apple released the Centris 610, 650, and Quadra 800. In these machines and since, Apple used surface mount crystal oscillators. Now that Apple was using surface mount crystal oscillators, there was plenty of area on the metal tabs of the oscillator accessible for easy soldering, you don't have to flip 1 and 14 and 2 and 3 around, and it will be on the top of the motherboard where there is more room to work, In June '93 Guy Kuo reported the first crystal swap of sorts on a Centris 610 to the net. He soldered pins 3, 5, 10, and 12 of a 14 pin socket directly onto the surface mount crystal oscillator. Because the pins on a TTL type crystal oscillator are at positions 1, 7, 8, and 14, he made jumpers between pins 5-7, 8-10, and 12-14. He disabled the on-board surface mount crystal oscillator with a jumper between 3-5. Then put the new crystal in the socket. This FAQ is also available on SUMEX (centris- 610-clock-mod-11). I 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 the 3M surface mount test clip arrived, and the test clip worked perfectly. I was running my Quadra 800 at 40MHz, with no problems, and 48MHz without the serial ports. A few days later I got several crystals, and found the highest frequency on my Quadra 800 to be 42MHz. I've tried it at 42.106MHz, and the serial ports did not work, so the cutoff for my 800 was at 42MHz. If you do not need your serial ports, 48MHz worked fine for me, and at 50MHz my Mac was not happy. And thus the removable test clip approach was born. So with this new approach, you can use a new crystal on a 475, 605, 610's, 650's, 660AV, 800, and 840AV. You do not have to do any soldering on the motherboard itself, just on the part you clip onto the surface mount crystal oscillator. Thus the clip can be removed at a later date. As with all the modifications, even though there is no sign that you have voided the warranty on the Mac, you have. 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." So you will need a 3M surface mount test clip. Make sure you get a surface mount test clip; I have not tried the regular IC test clips. I used an 8-pin one in my first clip, and later tried 12,14, and 16 pin clips. I'd say go with a 12 or 14; a 10 would be perfect. Digi-Key does not have the 12's, but they have the 14 and 16's. 14 pin, part# 923655-14-ND $7.31 16 pin, part# 923655-16-ND $7.74 These are the part numbers for the ones with gold leads; you only need 4 of the 14 or 16 leads, so if you plan to make several, buy some of the alloy ones, and put the extra gold pins in there. 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 in the socket. You can do the same here with gold and tin, and use the extra gold ones. Gold pins, part# ED3314 $0.73 Tin pins, part# ED3114 $0.57 You will also need an oscillator (more on this later), a little wire, soldering iron, and heat sink depending on the machine. For C610's I've used a heat sink. HS143-ND is the 0.600 inch one, and is plenty ($5.16). The C650's and Q800's already have a large heat sink, and do not get too hot at 28MHz and 42MHz respectively. I had an extra fan with my 800, but removed it, and it has been fine. The heat sinks come with the clips needed to attach them to the chip. These are a bit of a pain, you just have to work at it for a while. There may be several 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. Some people have been using the heat sink/fan combo's. I have not, but they seem to work fine as well. The new Quadra 650 has a heat sink which to me looks cheaper, and less efficient. Apparently these new computers are based on a new mask of the 68040 that runs at 25MHz without a heatsink (There is an "H" after the '040 and before the "RC"). This is the same mask as the 660av uses. If you do the modification on any of these, it would be best to add/replace the heat sink with one for a 68040 like the HS143-ND. How to put it all together. My last numbering scheme confused people, so maybe this will be a bit better. 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 with the test clip, leave pins in positions A2, A6, B2, and B6. Next solder a little jumper wire between pins A2 and A6. Now get the 14 pin IC socket, and remove all the pins but 7, 8, and 14. Solder a jumper wire from pin 7 on the IC socket to the jumpered pins on the clip, either A2 or A6. Also solder a jumper wire from pin 8 to pin B6, and pin 14 to pin B2. I used to clip off a little from the spring in the surface mount test clip, but now I buy a new spring with a lot less tension; they are like $0.30 at hardware stores, and I 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. The surface mount crystal oscillator on the mother board will have a frequency on it half that of your computer, so a C610 has a 10MHz, and a Q800 has a 16.6666MHz xtal. 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 7 months, nor any of the other ones I've done. In the C610 and C650's it is vertical, and in the Q800's it's horizontal, but it hangs on fine. Your computer may work with a faster crystal oscillator, but you may have problems with the serial ports, floppy controller, or memory. I would suggest that if you plan to purchase memory for your Mac that you purchase SIMMs that are say 10ns faster if possible. On most of these newer machines, the problem is with the serial ports. There is a modification to halve the frequency used by the serial ports, but it is quite expensive, requires a far more extensive modification at this time. To test it out, the best thing to do is just use it a while. You can run Speedometer (available at SUMEX) 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 by Central Point Software. I am told by a MacEKG technician that MacEKG does an extensive serial chip diagnostic, so I recently borrowed a copy of MacEKG from a friend, and on my Quadra 800@42MHz, it was fine as it should be. On my Quadra 800@45MHz, it was also fine, so apparently MacEKG does not detect the serial port problem. The current version of MacCheck is 1.0.5, and it now properly reports the computer frequency. If your Mac does not give the standard chime at startup it means your clip is only half on. It is disabling the surface mount oscillator, but not replacing it. Just remove the clip, and try again. Apparently there is some software and instructions to make a special cable on the recent Apple Developer's CD-ROM's that monitors the serial ports through the adb port and may be able to detect serial port problems. I'm not an Apple Developer, so I don't have access to this software. If someone has a copy, and it is legal to send me a copy I'd really appreciate it. Apple, do you want to sign me up as a developer? I'll take a PPC while you're at it... This is what I seem to be finding. The max is a max with serial ports functioning properly, and the next number is the next crystal tried where at least one of the serial ports did not work, or the computer did not work altogether. IIsi max at 27.5MHz 29.45MHz Q700 max at 35MHz C610 max at 28MHz 28.63636MHz C650 max at 28MHz 28.63636MHz Q800 max at 42MHz 42.106MHz Q650 max at 44.0640MHz 45MHz C660av max at 32MHz 35MHz Q840av max at 50MHz 64MHz 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 anyone done it themselves? The crystals I have found are: 10.0 12.0 $3.44 @ Digi-Key $3.75 @ Fry's 14.0 $2.99 @ Fry's 14.31818 $3.44 @ Digi-Key 15.0 $2.79 @ Halted Specialties Co. 16.0 $3.44 @ Digi-Key $4.46 @ Newark 18.0 Inductive 18.432 $3.44 @ Digi-Key $2.99 @ Fry's 19.6608 $3.44 @ Digi-Key $2.99 @ Fry's 20.0 $3.44 @ Digi-Key $4.46 @ Newark 21.0 21.053 21.22848 21.3333 21.384 $3.50 @ Electronics Etc. 22.0 22.0320 22.5 23.892 24.0 $3.44 @ Digi-Key $4.46 @ Newark 25.0 $3.44 @ Digi-Key $4.46 @ Newark 25.1750 $3.44 @ Digi-Key $2.99 @ Fry's 28.322 $3.44 @ Digi-Key $2.19 @ Fry's 36.0 40.0 $3.44 @ Digi-Key $4.46 @ Newark 48.0 50.0 $3.44 @ Digi-Key $4.46 @ Newark 55.0 (CMOS) $3.60 @ Digi-Key 55.0 $4.00 @ Electronics Etc. 58.90 66.6666 $4.70 @ Digi-Key $4.46 @ Newark 70.0 $6.49 @ Fry's Address' for parts suppliers: Fry's Electronics 340 Portage Ave Palo Alto, CA (415) 496-6000 Electronics Etc. 2738 10th Berkeley CA (510) 845-0169 Digi-Key (800) 344-4539 Newark 15 Crow Canyon Court San Ramon, CA 94583 (510) 743-0250 JAMECO Electronic Components 1355 Shoreway Road Belmont, CA 94002-4100 (800) 831-4242 Halted Specialties Co. 3500 Ryder St. Santa Clara, CA 95051 (408) 732-1573 (415) 969-1448 You can have crystals custom made, but it takes a while, and would be best to do in large quantities The best thing is to shop around, I have not had any of these custom made. If there is enough interest in a particular frequency, I'd be glad to place a large order and distribute the crystal oscillators at cost. If you have gotten any of these machines to go any faster **and** the serial ports still work, please let me know. Or if you have any questions or comments that should be added to this please e-mail me as well. I'm also interested in the names of any places that have a good selection of crystal oscillators. I'd like to have a more complete set so I can report cutoff's more accurately. Marc Schrier schrier@garnet.berkeley.edu