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Unix System Administration. Computer Hardware. ISA Jar Jar Binks, ISA Annoying. Industry Standard Architecture Original PC Bus 8-bit ISA (1980) 8.3MHz bus speed 7.0 Mbytes per second 16-bit ISA 8.3MHz bus speed 15.9 Mbytes per second. Microchannel? Narrow Urethra?.
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Unix System Administration Computer Hardware
ISA Jar Jar Binks, ISA Annoying • Industry Standard Architecture • Original PC Bus • 8-bit ISA (1980) • 8.3MHz bus speed • 7.0 Mbytes per second • 16-bit ISA • 8.3MHz bus speed • 15.9 Mbytes per second
Microchannel? Narrow Urethra? • “IBM proprietary” bus meant to extend the ISA bus • Primarily used in PS/2 and RS/6000 computers • 8, 16, 32-bit transfers • Introduced concept of “bus mastering” and “plug and play” • Not widely implemented and was rivaled by the EISA bus architecture
EISA, Wanna Buy a Vowel? • Originated in 1988 & 1989 by the “Gang of Nine” - AST, Compaq, Epson, HP, NEC, Olivetti, Tandy, Wyse & Zenith • Designed as alternative to microchannel • EISA connectors are a superset of ISA, so both EISA and ISA card will work in the same slot • Bus mastering, shared interrupts • 32-bits, 8.3MHz, 31.8 Mbytes/sec
Take the SBUS Downtown • Developed by Sun for its new SPARCstation systems in 1989 • Existing ISA and EISA weren’t powerful enough • Today, Sun is moving to the PCI Bus • However, SBUS I/O throughput is often 30-50% faster than PCI implementations • Over 3 million SBUS slots are in use today • SBUS is an IEEE standard
VLB - Very Large Band-aid? • VESA Local Bus • Created to help solve the need for large video transfers created by emerging graphical applications (e.g. Windows) • Separate faster bus to augment the ISA bus. • VL bus put on processors faster memory bus, or “local” to the processor. • VL slots accept both VL & ISA cards • 32-bit, 33MHz, 127.2 Mbytes/sec
PCI - Backwards, I C P • Successor to VLB, EISA, Microchannel and SBUS • Tends to co-exist with ISA still today • Supports, bus mastering, shared interrupts, plug-n-play • PCI - 32-bits, 33MHz, 127.2 Mbytes/sec • PCI 2.1-64-bits, 66MHz, 508.6 Mbytes/sec • New 100MHz bus support too!
Plug ‘n Pray • Plug-n-Play was designed to make it easier for to install PC cards • Macs and Suns had a type of play-n-play from their inception • Eliminated the need to set dip switches or jumpers on the expansion card • ISA cards were retrofitted with a type of plug-n-play
Let’s Get Graphic! • AGP - Accelerated Graphics Port • 32-bits wide (same as PCI) • Runs at full bus speed of 66MHz (PCI runs at 1/2 bus speed). • Minimum of 254.3 Mbytes/sec • 2X and 4X mode for faster data transfer • 4X = 1,017MB/sec, but theoretical 100MHz bus limit is 763MB/sec.
That’s UPA, not UPE • UPA - Ultra Port Architecture • Peak rate of 1.3GBytes/sec • Packet switching instead of a bus • Unlimited number of buses per system • Can tie together other, commodity buses such as PCI • Example: Sun Ultra Enterprise 450 has 6 PCI buses managed by a UPA
1+1 Does Not Always Equal 2 • Calculating bandwidth • ( bit-width/8 ) * ( bus-speed ) * (1,000,000/1,048,576 ) = MBytes/second • ( 32 bits / 8) * (33.3MHz) * (1,000,000/1,048,576) = 127.2 Mbytes/second • “M” in MHz = 1,000,000 (10^6) • “M” in Mbytes = 1,048,576 (2^20)
What Was I Talking About? Oh Yeah, Memory. • DRAM - centipede memory chips • SIMM - • 30 pin, 72 pin • ECC, EDO, FPM • DIMM • 168 pin • SDRAM, PC100 • RDRAM • 184 pin RIMM • 600-800MHz
Can You Factor the Form • AT, Baby-AT • ATX, mini-ATX • LPX, mini-LPX, NLX
Have you hard the one about… • Hard drive technology • MFM - Modified FM • RLL - Run Length Limited • ESDI - Enhanced Small Device Interface • SCSI - Small Computer • IDE - Integrated Drive Electronics
Muth Freakin Monster • Modified Frequency Modulation • Early drive type - more “compact” encoding scheme than FM (reduced redundant cycles by considering previous bit encoding) • Appx 2X capacity of FM • Used on floppies - “double density” • Drives had no processing electronics onboard
Requires Lotsa Luck • Run Length Limited • Modified encoding scheme again, associating flux patterns with bit sequences - appx 30% increase over MFM • Family of techniques: • PRML - permits weaker field strengths for higher areal density [track-to-track and linear] - flux reversals harder to detect - use DSP (30-40% increase in density) • EPRML - even higher densies (linerarly) using enhanced DSP - 20 to 70% increase (THIS IS USED TODAY)
Extra Stupid Development Initiative? • Enhanced Small Device Interface • Attempt to improve MFM/RLL interfaces • Short-lived due to SCSI/IDE release
Itsa Device Explosion!! • Integrated Drive Electronics - drive unit contains all interface electronics required. Attaches directly to system bus • Two devices per channel, two channels per system, device communication monopolizes the channel, length limits on cable • High system resource requirements due to direct interaction with system bus
Who you callin SCSI? • Small Computer System Interface • Supports higher device counts and longer cable lengths • Performance high for large numbers of devices • Permits command queuing and reordering • Separate bus and controller, offloads management and transfer functions from CPU • High cost • All devices can be targets or initiators (yes, even the PC)
You Are Elle’s • Hardware Specs • http://www.techfest.com/hardware/http://www.pcguide.com/ • Sun UPA Spec • http://www.sun.com/microelectronics/whitepapers/wp95-023.html
Wake Up! • What does PCI stand for? • What cards other than graphics cards fit in the AGP slot? • Why would Sun switch to PCI bus if SBUS can attain 30-50% better I/O throughput?