sutherla@qtp.ufl.edu (Scott Sutherland) (09/03/90)
As an avid Amiga user for over 3 years, I, and many others, often take multi-tasking for granted. Now I am starting to see new commercials for the IBM PS/2 line of computers which "hails the age of PC multi-tasking". AAAARRRGGGGHHH! (Now I feel better) They are pushing a product (?) or something called "micro channel". Can anyone tell me what this is? How does it compare in multi-tasking to the Amiga? What hardware/software is required as a minimum configuration? Does this have any relationship to MS Windows (I thought Windows was supposed to give multi-tasking to the IBM computers)?? Just curious. I like to know what the competition is up to. Scott Sutherland sutherla@qtp.ufl.edu BTW, has anyone seen the new commercial for the IBM PS/1, which big blue calls "the computer for everyone" (or some such nonsense) with an easy user interface and built in software?? Comments?
joseph@valnet.UUCP (Joseph P. Hillenburg) (09/03/90)
Well...MicroChannel is 3 years old now. Basically, IBM (Blah!) tries to make
a bus that beats the AT style. It does, but there are better one, like
NuBus, EISA, Zorro II, and or course Zorro III (Doesn't Zorro III have
better thoroughput than the others?).
-Joseph Hillenburg (Sultan of Asm)
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Those aren't bugs! Just undesirable features!UH2@psuvm.psu.edu (Lee Sailer) (09/04/90)
Micro Channel is a bus structure that allows all the devices in a computer to
talk to one another, including disks, memory, serial and parallel ports,
and co processors for whatever you add a coprocessor to do.
The original IBM pc/xt/at had such busses, too, but they were rarely
given particular names. Recently, those oldies got new names such as
ISA and EISA. EISA is the extended version of those original busses
with some more speed and power added.
Zorro II and now III are the Amiga's equivalent standards. MCA is an
imporvement over ISA, but is incompatible with EISA and Zorro. MCA and
Zorro II have roughly equivalent capabilities.
lee
PS I guess that offers the question, how hard would a Zorro <--> MCA
converter be? Beats me. 8-)daveh@cbmvax.commodore.com (Dave Haynie) (09/07/90)
In article <BNcXo3w162w@valnet> joseph@valnet.UUCP (Joseph P. Hillenburg) writes: >Well...MicroChannel is 3 years old now. Basically, IBM (Blah!) tries to make >a bus that beats the AT style. It does, but there are better one, like >NuBus, EISA, Zorro II, and or course Zorro III (Doesn't Zorro III have >better thoroughput than the others?). In some situations, Zorro III may have a better throughput than some of the other buses. Specifically, the CPU to Zorro III interface in an A3000 runs faster than the CPU to NuBus connection in any Mac. There are two reasons for this: [1] Being an asynchronous bus, there's no need for the A3000's main CPU to "sync-up" with the Zorro III bus, and the "termination lag" at the end of a Zorro III cycle (the time between the Zorro III cycle being over and the 68030 cycle actually ending) is reasonably small. NuBus is a synchronous bus, and for a CPU to talk to it, that CPU's cycle must be synchronized to the 10MHz NuBus clock. [2] Zorro III's answer to "burst" mode, officially called "Multiple Transfer Cycles", can result from a translation of the 68030's Cache Burst mode. On any bus that supports the concept of a "burst" mode, burst transfers are faster than single transfers. NuBus supports a "burst" concept, technically called a block transfer. But you can't translate 68030 Cache Burst into NuBus burst. As for EISA and MCA, it's hard to say. Both are synchronous, EISA using an 8MHz clock, MCA using a 20MHz clock (though they use the clocks differently). Both EISA and MCA use unmultiplexed address/data buses, as opposed to the fully multiplexed A-D NuBus and partially multiplexed A-D of Zorro III. This doesn't appear as a major factor in the basic specifications for any of these buses; all four have maximum theoretical bus speeds between 20 and 40 MB/s, at least in their current implementations. MCA, at least, has several variations. The PS/2 version is limited to 20MB/s. The PS6000 implementation sports a burst mode that lets it theoretically run at 40MB/s, and IBM has announced specifications, at least, to multiplex Address and Data in a 64 bit burst more, for 80MB/s, and next to change the drivers and double the bus clock frequency, for 160 MB/s. But those two modes don't exist yet. And the actual bus speeds are often far below the theoretical ones. All four 32 bit buses are very likely adequate for anything you need to plug into a 32 bit desktop computer. And speed isn't the only issue: complexity, cost, available board space and power, patent licensing, market, etc. all enter into the formula when you're designing a board for a machine. > -Joseph Hillenburg (Sultan of Asm) -- Dave Haynie Commodore-Amiga (Amiga 3000) "The Crew That Never Rests" {uunet|pyramid|rutgers}!cbmvax!daveh PLINK: hazy BIX: hazy Get that coffee outta my face, put a Margarita in its place!
daveh@cbmvax.commodore.com (Dave Haynie) (09/07/90)
In article <90246.143530UH2@psuvm.psu.edu> UH2@psuvm.psu.edu (Lee Sailer) writes: >Zorro II and now III are the Amiga's equivalent standards. MCA is an >imporvement over ISA, but is incompatible with EISA and Zorro. MCA and >Zorro II have roughly equivalent capabilities. Not exactly. MCA is a full 32 bit bus that runs at 20MHz, while Zorro II is a 16/24 bit bus that runs at 7.09-7.16MHz. So MCA will greatly outperform Zorro II. Feature-wise, most of the basic features lacking in ISA, which drove IBM to adopt MCA, are in Zorro II. These features include software configuration (ISA requires jumpers, versus Zorro II's AUTOCONFIG or MCA's POS), shared interrupts (on ISA, only one card could use any particular interrupt line), and multiple bus masters. > lee >PS I guess that offers the question, how hard would a Zorro <--> MCA > converter be? Beats me. 8-) It's certainly possible, but it could get a little ugly. Zorro II, Zorro III, and MCA handle certain fundamentals in very different ways. The only reason that Zorro III and Zorro II can coexist is that we were able to design a reasonably complicated bus controller to inscribe Zorro II cycles within Zorro III cycles, in a sense. And of course, I did design Zorro III to coexist with properly designed Zorro II devices, but the way it's done is a bit complicated. At the least, you would lose a considerable amount of performance going through an MCA bus converter. -- Dave Haynie Commodore-Amiga (Amiga 3000) "The Crew That Never Rests" {uunet|pyramid|rutgers}!cbmvax!daveh PLINK: hazy BIX: hazy Get that coffee outta my face, put a Margarita in its place!
sokay@richard.mitre.org (Steve Okay) (09/08/90)
In article <1132@orange9.qtp.ufl.edu> sutherla@qtp.ufl.edu (Scott Sutherland) writes: > > As an avid Amiga user for over 3 years, I, and many others, often >take multi-tasking for granted. Now I am starting to see new commercials >for the IBM PS/2 line of computers which "hails the age of PC multi-tasking". >AAAARRRGGGGHHH! (Now I feel better) They are pushing a product (?) or >something called "micro channel". Can anyone tell me what this is? How does >it compare in multi-tasking to the Amiga? What hardware/software is required >as a minimum configuration? Does this have any relationship to MS Windows >(I thought Windows was supposed to give multi-tasking to the IBM computers)?? > >Just curious. I like to know what the competition is up to. > >Scott Sutherland >sutherla@qtp.ufl.edu > > >BTW, has anyone seen the new commercial for the IBM PS/1, which big blue calls >"the computer for everyone" (or some such nonsense) with an easy user interface >and built in software?? Comments? In article <1132@orange9.qtp.ufl.edu> sutherla@qtp.ufl.edu (Scott Sutherland) writes [comments about PS/2s and MCA deleted] >BTW, has anyone seen the new commercial for the IBM PS/1, which big blue calls >"the computer for everyone" (or some such nonsense) with an easy user interface >and built in software?? Comments? I heard a commercial for them on the radio the other night, and there was a brief blurb about how it was "so simple, it even tells you what to do and how to do it", or some similar twaddle.The whole commercial was a little condescending to even the "naive user"'s level of techno-literacy.It kind reminded me of the Ziggy cartoon with a PC glaring at him saying "Look bozo, thats 3rd time in a row you've hit the wrong key. Go play PacMan and let me handle this!". I also saw one at Fed Micro '90 in D.C. yesterday. It's this little tiny box with a non-AT type keyboard, with one disk drive and slots that look like expansion ports but are really just ventilation slats(!???). It was running an "Intro to your PS/1" -type demo in blocky, CGA type graphics with these pitiful little piezo bleeps coming from it. First time I've ever felt sorry for a computer. ---Steve ------------------ Stephen Okay Technical Aide, The MITRE Corporation OKAY@TAFS.MITRE.ORG Disclaimer: I get *MYSELF* in enough trouble with my opinions, why inflict them on MITRE?