At 23:30 +1000 09/29/2002, Peter wrote: >Unfortunately, I cannot find any tech specs about the original Umax >secondary processor card. I only know that the jumper settings on the >secondary card differ from the primary card and it seems a small flatcable >is bridging the primary and secondary card. I can only guess what the >purpose of this cable is. >That's all I know so far. > >I am also aware of the fact that I will have to sacrifice a bit in regards >to the cpu/bus ratio because of the difference in clock speed between both >processor cards (i.e. 200 and 233MHz) > >Is there anyone out there who owns an S900DP with a secondary CPU installed? >What I would like two know is the jumper settings of this card.how the flat >cable is connected (if any) and how the narrow space for a heat sink has >been solved.
I don't think there are jumper settings on the secondary card, because it is always used with the cable attached. That isn't really a jumper bank. It's a ribbon cable connector. The heat sink space was solved by Umax building the card with the CPU on the opposite side from normal so that the heat sink would face outwards. The primary and secondary CPUs use different interrupt and bus arbitration pins. These pins are both present in the primary and secondary CPU slots. However, if you install two primary cards, they'll both be trying to use the primary interrupt and arbitration lines and neither CPU will be on the secondary interrupt and arbitration lines. This, obviously, won't work. Now my memory may be faulty, so here are the things I'm in doubt about. I'm not 100% certain that both CPU slots are wired just the same. That's what I remember, but it's not a certainty. If, for example, Umax wired the secondary interrupt and arbitration wires to the pins ordinarily used for the primary interrupt and arbitration lines in their secondary CPU slot, then this could conceivably work. You could check this with a continuity meter. Here's the primary CPU slot pinout. You can figure most anything else out using this and a continuity meter. Keep in mind there may be errors. I certainly didn't get this from Apple: 1 5V 2 5V 3 5V 4 5V 5 5V 6 5V 7 12V 8 DBWO 9 CLK 10 CLK 11 CLK 12 CLK 13 CLK 14 CLK 15 CLKID[0] 16 CLKID[1] 17 CLKID[2] 18 HRESET 19 PBR 20 PDBG 21 PBG 22 ARTRY 23:54 A[31:0] 55 SINT 56 SBR 57 SDBG 58 SBG 59 DBDIS 60 TBST 61 TSIZ[0] 62 TSIZ[1] 63 TSIZ[2] 64 TT[0] 65 TT[1] 66 TT[2] 67 TT[3] 68 TC[0] 69 AACK 70 TS 71 TA 72 CI 73 TEA 74 5V 75 5V 76 5V 77 5V 78 5V 79 5V 80 DRTRY 81 PINT 82 NC 83:146 D[0:63] OR DL[0:31], DH[0:31] Where you see a set of pins that are present both as Px and Sx that indicates primary x and secondary x. For example DB, DBG and BR are the arbitration lines. They are present as PDB, PDBG and PBR and the corresponding 'S' prefixed pins. The Mac CPU slot was designed from the outset to support two processors in a single slot, such as the Daystar and Apple dual CPU cards. Umax was a little weird for splitting them into separate slots. I hope that helps. Jeff Walther P.S. Oh, and many CPU cards have tiny numbers at the ends of their edge connectors. That should let you figure out which pin is which. Seventy-three pins to a side. -- SuperMacs is sponsored by <http://lowendmac.com/> and... Small Dog Electronics http://www.smalldog.com | Refurbished Drives | Service & Replacement Parts [EMAIL PROTECTED] | & CDRWs on Sale! | Support Low End Mac <http://lowendmac.com/lists/support.html> SuperMacs list info: <http://lowendmac.com/supermacs/list.shtml> --> AOL users, remove "mailto:"; Send list messages to: <mailto:[EMAIL PROTECTED]> To unsubscribe, email: <mailto:[EMAIL PROTECTED]> For digest mode, email: <mailto:[EMAIL PROTECTED]> Subscription questions: <mailto:[EMAIL PROTECTED]> Archive: <http://www.mail-archive.com/supermacs%40mail.maclaunch.com/> Using a Mac? Free email & more at Applelinks! http://www.applelinks.com
