thecloud@dhw68k.cts.com (Ken McLeod) (09/26/89)
The following information comes from the "IIci Technical Tour" stack,
and hopefully should answer at least some of the questions that have
been posted here recently. The usual disclaimers apply.
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oo Memory Upgrade Issues oo
To satisfy the timing requirements of the 25 MHz 68030, the IIci requires
a RAM speed of 80 ns or faster. To satisfy the requirements for burst
reads, the IIci requires RAM that supports fast page mode. Use of RAM
that does not satisfy both requirements will cause the IIci to crash.
The part numbers for Apple labeled SIMM upgrades and service parts that
meet these requirements are listed below:
Finished Goods RAM Upgrade Packages:
Upgrade Size Part Number
---------------------------------------------------
1MB, 80 ns, Fast Page Mode M0291LL/A
4MB, 80 ns, Fast Page Mode M0292LL/A
4MB (Parity), 80 ns, Fast Page Mode M0294LL/A
Service Goods RAM SIMM Parts:
RAM Density Part Number
---------------------------------------------------
256KB, 80 ns, Fast Page Mode 661-0519
1MB, 80 ns, Fast Page Mode 661-0520
1MB (Parity), 80 ns, Fast Page Mode 661-0546
Unknowing or curious users will undoubtedly try RAM SIMMs that are rated
slower than 80 ns. In most cases, those users will find that the slower
RAM will work for a short time. However, the IIci unit WILL eventually
crash with a serious system error. There are several reasons why a IIci
will not always crash immediately on power up when slower RAM is installed.
They include:
o Frequently, RAM speed is rated conservatively. As a result, a chip may
actually be faster than it is rated under certain circumstances.
o Many of the RAM SIMMs that are available on the market for use in the
Macintosh SE/30, II, IIcx and IIx, including some sold by Apple, are
rated for 100 ns, which puts them close to the 80 ns requirements.
o RAM speed is higher in a cooler chip than in a warmer chip with the same
rating. When the Macintosh is first turned on, the chips are cool.
After the unit is turned on, the chips will heat up, which causes them
to slow down.
The rules that must be followed when installing RAM SIMM modules in a IIci
are:
o All SIMM boards within a bank must be the same density.
o Within a bank that contains RAM, all four slots in that bank must be
filled.
NOTE: Although the following two rules apply to RAM configurations in all
other modular Macintosh models, they ARE NOT required in the IIci.
o All SIMM boards must be installed in Bank A for configurations that fill
only one bank.
o Higher density SIMM boards must be installed in Bank A for configurations
that have different densities in each bank.
Bank A and Bank B each hold 4 SIMM strips. The following Apple memory
upgrades work in the IIci:
Bank A and B: Can hold SOJ (small) or DIP (tall) SIMM strips.
Upgrade Options for each bank:
o One M0291LL/A Apple 1MB Memory Expansion Kit (1MB)
o One M0292LL/A Apple 4MB Memory Expansion Kit (4MB)
or
o One M0294LL/A Macintosh 4MB Parity Memory Expansion Kit (4MB)
1MB IIci (Starting Configuration):
End Cofig. Upgrade Needed
----------------------------
1MB *1
2MB 1-M0291LL/A
4MB 1-M0292LL/A *1, *2
5MB 1-M0291LL/A *3
8MB 1-M0292LL/A
4MB IIci (Starting Configuration):
End Cofig. Upgrade Needed
----------------------------
4MB *1
5MB 1-M0291LL/A *3
8MB 1-M0292LL/A
4MB Parity IIci (Starting Configuration):
End Cofig. Upgrade Needed
----------------------------
4MB *1
5MB *4, *3
8MB 1-M0294LL/A
*1 - To achieve this configuration, all four SIMM modules can be installed
in either Bank A or Bank B. If built-in video is to be used, all four
must be installed in Bank A. If all four are installed in bank B,
built-in video will be disabled.
*2 - To achieve this configuration, the new SIMM modules will be installed
in place of the original SIMM modules.
*3 - To maximize performance, install the 1MB SIMM modules in Band B and
the 256KB SIMM modules in Bank A. Although the opposite configuration
can be installed, the effects of cycle stealing for built-in video can
be minimized by installing the smaller of the two in Bank A.
*4 - Apple is not offering 256KB Parity SIMM modules, so this configuration
would have to be achieved with third-party 256KB SIMMs.
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--
========== ....... =============================================
Ken McLeod :. .: UUCP: ...{spsd,zardoz,felix}!dhw68k!thecloud
========== :::.. ..::: INTERNET: thecloud@dhw68k.cts.com
//// =============================================gillies@m.cs.uiuc.edu (09/28/89)
Here are some IIci questions:
If you buy a 1Mb IIci, and want to use the built-in video 8-bit video,
(a) What is the CPU slowdown (%) due to cycle-stealing?
(b) Isn't the resulting system memory (1Mb - 640*480 bytes)
pathetically small?
So doesn't that mean you must buy 2Mb of memory to use the built-in
video? I wonder if the built-in video is cost effective AT ALL on the
IIci?? Or is it just a heck of a lot faster than any Nubus video
cards on the market?
Don Gillies, Dept. of Computer Science, University of Illinois
1304 W. Springfield, Urbana, Ill 61801
ARPA: gillies@cs.uiuc.edu UUCP: {uunet,harvard}!uiucdcs!gilliesxdaa374@ut-emx.UUCP (William T. Douglass) (09/28/89)
In article <8400168@m.cs.uiuc.edu> gillies@m.cs.uiuc.edu writes: >If you buy a 1Mb IIci, and want to use the built-in video 8-bit video, > >(a) What is the CPU slowdown (%) due to cycle-stealing? The explanation from a local Apple rep was that the built-in video is actually faster in 1-bit mode than using a NuBus video adaptor. The two are about equivelant in 4-clolr mode, and the NuBus card wins in 8-bit mode. Of course, 32-bit color requires an external adaptor. >(b) Isn't the resulting system memory (1Mb - 640*480 bytes) >pathetically small? >So doesn't that mean you must buy 2Mb of memory to use the built-in >video? This one is strange. What are you refering to? The system memory in the IIci is not limited to 1 meg - the system I saw was 4MB & going strong. It can be expanded to greater RAM amounts, of course. As an aside, the ROM is 32-bit clean (says Apple.) -- Bill Douglass, TCADA "I dreamed I was to take a test, in a Dairy Queen, on another planet." L. Anderson
rcfische@polyslo.CalPoly.EDU (Raymond C. Fischer) (09/28/89)
In article <8400168@m.cs.uiuc.edu> gillies@m.cs.uiuc.edu writes: > >Here are some IIci questions: > >If you buy a 1Mb IIci, and want to use the built-in video 8-bit video, > >(a) What is the CPU slowdown (%) due to cycle-stealing? About 5-15% in 8bit mode. Depends on the usual dozen or so variables. >(b) Isn't the resulting system memory (1Mb - 640*480 bytes) >pathetically small? Yup. The default screen depth on 1 1MB machine is 1 bit. Only when you have at least 2MB does it default to more. Of course, the defaults can be changed. >So doesn't that mean you must buy 2Mb of memory to use the built-in >video? I wonder if the built-in video is cost effective AT ALL on the >IIci?? Or is it just a heck of a lot faster than any Nubus video >cards on the market? I couldn't get by with just 1MB on my SE/30! And it doesn't use ANY of the RAM for video. Fortunately, RAM is getting cheap. 4MB of RAM is probably about the same price as an 8bit video card, and you still have all that extra RAM to play in. Faster? Yes and no. Yes in 1bit to 4bit modes. No in 8bit. This info is condensed from the article in the Oct. Byte. Interesting article too, the writer nearly gushes over the new machines (the portable and the IIci). Rather in the tone of MacUser or MacWorld. Ray Fischer rcfische@polyslo.calpoly.edu
hallett@positron.uucp (Jeff Hallett x5163 ) (09/28/89)
In article <8400168@m.cs.uiuc.edu> gillies@m.cs.uiuc.edu writes: > >Here are some IIci questions: > >If you buy a 1Mb IIci, and want to use the built-in video 8-bit video, > >(a) What is the CPU slowdown (%) due to cycle-stealing? There really isn't much CPU slowdown according to Apple. It's the memory problems that kill you (see below). Apple people are claiming that the IIci using builtin video is still much faster than a IIcx using a video card. >(b) Isn't the resulting system memory (1Mb - 640*480 bytes) >pathetically small? > Not too bad, ~690K. However, you won't be able to run much (although it will run FAST). Apple recommends at least 4Mb RAM when using the builtin video. Besides, you'll need 2Mb anyway to make good use of System 7.0. >So doesn't that mean you must buy 2Mb of memory to use the built-in >video? I wonder if the built-in video is cost effective AT ALL on the >IIci?? Or is it just a heck of a lot faster than any Nubus video >cards on the market? > Well, for some off-the-cuff figures: IIci with 8 bit color = $IICX_COST + 1500 + 400 + $MONITOR_COST IIcx with 8 bit color = $IICX_COST + 1000 + $MONITOR_COST (400 = 4Mb RAM, 1500 = base difference in retail cost, 1000 = cost of RasterOps video board) There isn't much of a difference and you still have 3 slots free and somewhere around 40% speedup. If you get some kind of discounts, the difference drops slightly. Even more, considering the cost of RAM these days, most people will be getting additional RAM in their machines anyway, lowering the difference further. My questions pertain to functionality more than cost. I was wondering how locked in you are to using Apple's monitors with the builtin video. Theoretically, the NEC ColorSync has the same density and refresh rate as the Apple 13" RGB HiRes monitor (according to RasterOps). Therefore, will the NEC monitor work on the builting video? Any Apple-types out there know? -- Jeffrey A. Hallett, PET Software Engineering GE Medical Systems, W641, PO Box 414, Milwaukee, WI 53201 (414) 548-5163 : EMAIL - hallett@gemed.ge.com "Your logic was impeccable Captain. We are in grave danger."
t-jlee@microsoft.UUCP (Johnny Lee) (09/29/89)
In article <18891@ut-emx.UUCP> xdaa374@emx.UUCP (Bill Douglass) writes: >In article <8400168@m.cs.uiuc.edu> gillies@m.cs.uiuc.edu writes: [Stuff Deleted] > >>(b) Isn't the resulting system memory (1Mb - 640*480 bytes) >>pathetically small? >>So doesn't that mean you must buy 2Mb of memory to use the built-in >>video? >This one is strange. What are you refering to? The system memory in the >IIci is not limited to 1 meg - the system I saw was 4MB & going strong. >It can be expanded to greater RAM amounts, of course. I think he is referring to the fact that the memory for the screen is located in main memory (i.e. along with the system and app heaps). So with an 8-bit deep screen, plus a normal System (~400K) one is not going to be able to run many mainstream business-type apps or graphics programs( especially under Multifinder). > >As an aside, the ROM is 32-bit clean (says Apple.) > How did the guys at Apple do this? From what I remember, in the August MacTutor, there was an article mentioning the fact that the main problem in getting a 32-bit clean ROM were CDEFs which use the highest bit passed to the CDEF to signal something. How about wait states in the IIci? Are there any? (obviously there are if a cache card is going to help performance,right?) Johnny Lee t-jlee@microsoft.UUCP ...!uw-beaver!microsoft!t-jlee