From: bgrubb@dante.nmsu.edu (GRUBB)
Subject: Mac & IBM Info-Version 1.8.0
Date: 20 May 1993 16:02:12 GMT

{Send follow ups to comp.sys.mac.advocacy. Sorry about the header but the 
Pnews here does not let one easily change the headers and I gave up after a 
year of trying. This sheet is also available by FTP on sumex-aim.stanford.edu 
(36.44.0.6) in the info-mac/report as mac-ibm-compare180.txt.}
{Changes: PowerPC 601 info corrected, thank you list shortened to those with 
direct sitations and moved.}
Mac & IBM Info-Version 1.8.0
Note:  for proper reading off line this document should be in 9 point Monaco.

The reason for this general data sheet is to consolidate and condense the 
information out there, so that people in both camps can be clear and accurate 
about what they are saying about their machines.  Since computer technology 
is always changing there are always going to be points in which the sheet will
be lacking or incorrect on information.  So, please just don't say the sheet 
is incomplete or incorrect but also give me clear and concise information to 
make the needed corrections.  All prices are in US dollars.
To keep this data sheet accurate please provide, if possible, article 
citations for the information provided or corrected and keep the opinions to 
a minimum.  As this is a general data sheet, keep the info provided short and 
simple. Finally, keep the information relevant to the section corrected. Thank
you.

 Contents
CPUs
Hardware
 PowerPC rumors
 Monitor support
 Expansion
Operating system
 Mac
 IBM
 PowerPC
 OS Number Crunching
Networking & Printing

The CPUs
 Note: I am only showing Motorola & Intel CPUs used in Mac and most IBM/PC 
clone machines. For example, since Apple never used the Motorola 68008 and 
68010 in the Mac these chips are not listed. Years indicate first to last year
of discontiued CPUs.
Cache note:  a cache is "where data can be stored to avoid having to read the 
data from a slower device such as a disk" (Dictionary of Computer Terms:61-
DTC).  Both IBM and Mac use caches external to CPUs which increase the speed 
of the CPU but are not a part of it.  Since there are many different external 
caches {CPU-Mac and IBM; SCSI, video, disk and static RAM-Mac}, each having a 
different effect on CPU performance, with some built-in {present Macs}, other 
optional but installed {IBM}, and are machine, seller or expansion dependent, 
I have decided to leave them out of the list.
Note:  ALU is industry's de-facto standard for CPU bit classification.
IBM     ALU  Registers    External     CPU     Features/
CPU                     data  address cache    Notes
8088(6) 16      16     8 (16)   20    none     {1981-9} {198?-9}
80186   16      16       16     20    none     {198?-9?} segmenting
80286   16      16       16     24    none     80186 + Protected Mode
386sx   32      32       16     24    none     16 MB maximum RAM as is 286
80386   32      32       32     32    none     MMU & 32-bit Protected Mode 
486sx   32      32       32     32   one 8K    80486 - FPU
80486   32      32       32     32   one 8K    80386 & FPU
486dx2  32      32       32     32   one 8K    doubled internal clock rate*
486dx3  being demoed. 20/60 MHz, 25/75 MHz, and 33/99 MHz planned.
Pentium 32      32       64     32   8K code,  CISC chip with RISC-like  
   5                                 8K data,  features, 2-issue superscalar, 
 [P 5]                               Branch    386 Write-Back, 64-bit FPU, 
                                     target    pipelining; 66 MHz: SPECint92: 
                                               64.5; SPECfp92: 56.9 13 watts**

386sl: low power(3.3V) 386sx with built-in power management. Laptop use.
386slc: IBM 5V 386sx with a 16k on-chip cache added (John H. Kim).  As far as
 John H. Kim knows it is only used on IBM models.
486slc: Neither of two chips that have this name have a FPU.  Cyrix: basically
 486sx in 386sx socket with 1k cache and improved integer math speed.  IBM: 
 equivalent to 486sx except it has a 16k on-chip cache.
486SLC2: IBM chip equivalent to 486dx2 - FPU and with 16k on-chip cache

* ex. for 486dx2/50, chip runs 50 MHz rest of machine runs at 25 MHz.
**(PC Week 04/12/93; PC Mag 4/27/93:138; MacWeek 4/26/93; BYTE June 1993:Intel
flyer) "The latest in a line of CISC chips" (PC Mag 4/27/93:110)  Machines not
to be announced until at least May 1993 (PC Week 2/08/93) and volume shipment 
not until Oct 1993.  ~$900 a CPU; systems $5000 and up (PC Mag 4/27/93:110; 
BYTE May/93:94). 

Mac     ALU  Registers  External bus   CPU     Features/
CPU                     data  address cache*   Notes
68000   16      32       16     24     none    {1984-1993} 16 MB limit**
68020   32      32       32     32   256 code  {1987-1992} parallel processing
68030   32      32       32     32   two 256   68020 + MMU, 16K burst mode
68LC040 32      32       32     32    two 4K   68040 - FPU
68040   32      32       32     32    two 4K   MMU, FPU, pipelining, doubled 
                                               internal clock rate***
68050   development discontinued in favor of 68060
68060   32      32       32     32    Branch   68040 + a better FPU,  
                                      target   superscaler pipelining, cache 
                                               line bursts, equivalent 
                                               capabilities & speeds to 
                                               Pentium*#

Note: the now defunct NeXT machine used the 68030 and 68040.
*includes data and instruction {code} caches.  The 68030, 68LC040, & 68040 
have built-in caches for both.
**68000 Mac designs created a 4 MB limit.
***The 040 has 2 clocks, an internal processor clock [PCLK] that is 2x freq of
external bus clock [BCLK] which is the one used to rate the chips 
(Bradley Lamont; Motorola 68040 data book).  Some compilers produce programs 
sensitive to the PCLK/pipelining and act as if the 68040 was a clock doubler 
chip, but this very compiler and program dependent.  Overall the 68040's speed
is presently more in line with the 486dx then the 486dx2.
*#Motorola claims (PC Week 09/07/92; PC Week 09/14/92).

As the PowerPCs are to be in both IBM and Mac machines I have listed them 
separately to eliminate redundancy.  They are Motorola/IBM CPU RISC chips.

PowerPC ALU  Registers  External bus   CPU     Features/
CPU                     data  address cache    Notes
MPC601  32    int 32     64     32     32K     66 MHz:  SPECint92: 50; 
[98601]       fp  64                 combined  SPECfp92: 80. 6.5 {50 MHz} -
                                       I/D     9 {66 MHz} watts*
MPC603: low power MPC601 for desktop & portable systems. Out by end of 1993.
 [603]
MPC604: high performance MPC601 for high end machines. Out by 1st Q 1994.
 [604]
MPC620  64      64       64     64     32K      Out by mid 1994.
 [620]                               combined    
                                       I/D      

*(PC Week 04/12/93; PC Mag 4/27/93:138) The SPECint92: 60 (MacWeek 4/26/93) 
was a typo.  Old name MC98601.  Some NuBus boards containing early samples of 
PowerPC 601 were given to Apple's "A-list" developers (PC Week 12/7/92; 
MacWeek 12/14/92), and select venders were sent sample MPC601 chips by 
Motorola (PC Week 2/08/93).  MPC601/50 MHz-$280; MPC601/66 MHz-$374 (PC Week 
4/12/93).  A MPC601/80 MHz was used in a PowerPC Mac prototype (MacWeek 
5/10/93).  Rumor-there are plans to produce MPC601/80 chips in several months 
(MacWeek 5/17/93).  Systems: see Hardware, PowerPC rumors.

CPUs Comparison List
As a general rule of thumb Motorola chips are faster than Intel chips at the 
same frequency {030/25 ~= 386/33; 040/25 ~= 486dx/50}, but Intel has chips at 
higher frequencies than Motorola, so this evens out.  The Macintosh Bible 4th 
ed. supports the comparisons between Intel and Motorola chips for the 68020 
and above.

<=80186    ~ 68000 {16-bit vs 16/24/32-bit chip.  The 4 MB limit on the 68000 
Macs brings the 68000 in them down to the 80186 and lower chips, otherwise the
68000 would compare to the 80286.}

286        ~ 68020 {hardware segmenting vs. 68020's 32-bit ALU and having no 
usable built-in MMU unlike their successors [80386, 68030].  The hardware 
segmenting's protected mode is used by OS/2 1.0 => and Windows 3.X. The use of
the hardware segmenting and their 16-bit nature put the 286 between the 60000 
and 68030 in features and the LC's 16-bit data path strenghthens the 286 ~ 
68020 comparison.}

386       ~ 68030 {Two 32-bit chips with MMUs, and protected memory.  A/UX 3.0
is at present the only Mac OS to use the 68030's protected memory feature for 
apps.  System 7.x uses this feature to protect a RAM disk created by the 
Memory control panel which is supported only on Powerbooks and Quadras.  The 
Color Classic and LCII 16-bit hardware data paths makes the 68030s in them 
comparative to 386sxs.}

486sx   ~ 68LC040 {same as 486 and 68040 without the FPU; used as a low cost 
solution for people who do not need the FPU.  Only with programs sensitive to 
PCLK & pipelining does the 68LC040 behave like a 486SLC2 - chip cache or a 
'486dx2sx'.}

486     ~ 68040 {two 32-bit microprocessors with built-in FPU, MMU, 8K 
internal cache (which is implemented as two 4K caches in the 68040 and one in 
the 486).  Only with programs sensitive to PCLK & pipelining does the 68040 
behave like a 486dx2.}

Pentium   ~ 68060 {Both are planned to be superscalar but both have heat 
problems.  These chips may flounder against the cheaper (PC Week 4/12/93; PC 
Mag 4/27/93:110), earlier released (PC Week 12/7/92; MacWeek 12/14/92; PC Week
2/08/93), less leat producing {160 degrees F for Pentium (PC Mag 
4/27/93:118)}, and partly ported to PowerPC chips.} 

PowerPC   = PowerPC {This CPU line is planned to run programs from DOS, 
Windows 3.x, OS/2 and Mac OS on top of PowerOpen-A/UX 4.0 [UNIX] and later 
Pink [Taligent OS] in a way similar to how SoftPC or OS/2 does DOS.}

Hardware 
{In an effort to remove the 'reconfiguring the system almost every time you 
add something' requirement for add-in cards, drivers, video, and operating 
systems in the IBM world; Intel, Microsoft, and 12 other hardware and software
developers are working out 'plug and play' standards (PC Week 03/08/93).}
PowerPC Rumors
IBM PowerPC: late 1993 (MacWeek 7/13/92; PC Week 3/15/93);  ~$3000-
 MicroChannel bus, XGA video, 8 MB RAM, 200 MB hard-drive (Computer Reseller
 News, 3/22/93). Will run native version AIX and Mac apps (PC Week 3/15/93)
 and support DOS; no comments on Windows app compatablity.
Apple PowerPC {Tesseract}: Jan 24, 1994; near LC line prices {~$2000, down
 from ~$3000 projection (MacUser 9/92:146)}- MPC601/50 MHz, 4/8 MB RAM, a
 2.8 MB floppy drive (MacWeek 3/22/93).  The Centris 610 and 650, Mac IIvx
 and IIvi, and Quadra 800 products are all planned to have PowerPC upgrades
 (PC Week 5/10/93; Apple Computer).

Color Support/Display
 Mac: 30.24 MHz Pixel Clock standard.  All present Macs support the use of 
32-bit color through 32-bit color QuickDraw in ROM.  32-bit color QuickDraw 
allows an almost transparent capability to display and edit X-bit images in Y-
bit color and retain ALL the colors of X-bit color [Where X and Y 
independently are 1, 2, 4, 8, 16, or 32] regardless of monitor resolution 
{69 dpi [12" color] to 94 dpi [PaletteBook]} or monitor type {including 
autosynchronous VGA, MCGA and SVGA monitors with ranges including 66.7 hz 
vertically and 35 kHz horizontally and only a hardware video adaptor (MacUser 
Aug 1992: 158-176)}.  Older machines that supported color {SE/30, II, IIX, and
IIcx} had only 8-bit color in ROM and needed a software patch to use 32-bit 
color (MacUser Special 1993:28-29).  
To keep costs down and speed up most Macs have only 8 or 16 bit display 
capability built-in, but most of those can be expanded to display 24-bit 
color.  Presently QuickDraw is optimized for 72 dpi display; QuickDraw QX will
change this and is expected to support all resolutions equally.
In Macs with NuBus slots QuickDraw allows more then one monitor to be used in 
any combination, from several monitors showing the same thing to multiple 
monitors acting as one large large monitor with any degree of overlap of the 
pictures.
VRAM: Video RAM.  Standard for present non-PowerBook Mac's handling of 
 built-in video {from a 24-bit color palette}. VRAM provided runs a 8-bit
 color 640 x 480 display; all VRAM machines expand to 16-bit color or 832 x
 624 {8-bit} display.  The Quadras {except Q800} expand to 24-bit color
 {640 x 480 and 832 x 624 only} (TidBITS #173). 
Sound output:  Standard in all Macs since the 128K.  Stereo sound became 
 standard with the SE/30.

IBM:  Even though PCs have ROM BIOS definitions of how the operating system 
interacts with the video hardware (Nan Zou), the use of drivers bypassing 
BIOS, video hareware inconsitancies {see Super VGA below} and nonstanderzation
of clone BIOS have left resolution of video display hardware/OS/program 
interaction up to the OS and video hardware in question (Faisal Nameer 
Jawdat). In addition, IBM and clone makers never bothered to provide a 
standard hardware mechanism for software to determine what display mode is 
actually present (Matt Healy) nor a standardized screen-drawing toolbox {like 
Mac's QD}. As a result the OS must be very well written to detect some modes 
and/or use them consitantly, especially with some third party cards.  At 
present things are so dependent on the interaction of the program, OS, print 
driver and monitor card that editing 32-bit pictures regardless of color mode,
program, and monitor type/card combination as one can do on the Mac is near 
impossible.  DOS has the biggest problem, Windows is better, and NT-OS/2 are 
the best but this is a OS feature not hardware and so is inconsitant from OS 
to OS and even from program to program.
Later IBM machines will have integrated graphics accelerators, faster 
processors, and modular upgradeability and may have built-in sound cards, CD 
ROM, and Ethernet (PC Week 12/14/92).  
MDA: Monocrome Display Adapter
 original character-mapped video mode, no graphics, 80x25 text.
CGA: Color Graphics Array
 320x200 4 colors or 640x200 b/w, 16 color palette, bad for the eyes.
EGA:  Enhanced Graphics Array
 640x350 16 colors from 64 color palette [and some lower res]; some versions 
 could run at 256 colors, bearable on the eyes.
VGA:  Video Graphics Array*
 320x200 at 256 colors, 640x480 at 16 colors, and some others, these two are 
 the most commonly used.  All modes have 256 colors, from a 18-bit {IBM} to 
 24-bit {IBM/Mac} color palette.  25.175 MHz Pixel Clock (Mel Martinez). 
 Monitors use analog input, incompatible with TTL signals from EGA/CGA etc. 
MCGA:  Multi-Color Graphics Array*
 subset of VGA that provides all the features of MDA & CGA, but lacks some EGA
 and VGA modes, like VGA 640x480x16 (DCT).  Common on the initial PS/1
 implementation from IBM and some PS/2 Models.
SVGA:  Super VGA*
 This is not a standard in the way the others were, but instead was a 'catch 
 all' category for a group of video cards.  As such, with each manufacturer 
 using their own implementation scheme, SVGA was chaos with people debating
 as to what is SVGA and what is not.  In an effort to make SVGA more of a 
 standard VESA was established and is used in the newer units, but things
 are still a mess.  Video is either 512K [~1990] or 1 MB [today], resolution
 of 800x600 and 1024x768 at 16 and 256 colors are common, newer ones [since 
 1990] have the Sierra HiColor RAMDAC, giving 15-bit 32,768 colors at 800x600,
 some of the very newer ones [~6/92] can do 24 bits per pixel [usually 
 at 640x480].  Speedwise, too much variation, some very slow [Ex. Western
 Digital Paradise based], some very fast [Ex. S3 86C911 based], some are
 so-so [like Tseng ET4000].  Some limiting factors overcome by 40MHz VL Bus
 & 386's linear address mapping were:  8.33 MHz ISA bus, AT architecture where
 CPU looks at the card through a 64K "window", etc.
Other non-SVGA standards: 
8514/a
 IBM's own standard, interlacing graphics accelerator with graphics functions 
 like linedraw, polygon fill, etc. in hardware. Some clone implementations 
 from ATI are the fastest video available today, though some clone models do 
 not have interlacing. Max resolution: 1024x768x8b
TMS34010/34020: high end graphics co-processors, usually >$1000, some
 do 24-bit, speeds up vector-oriented graphics like CAD.
XGA:  eXtended Graphics Array {May be used in IBM PowerPC}
 newer and faster than 8514/a, only available for MCA bus-based PS/2s, clones 
 are coming out soon.  Emulates VGA, EGA, and CGA (DCT).  Max resolution: 
 1024x768x8b, also some 16 bpp modes.
XGA-2
 Accelerates graphics functions up to 20 times faster than standard VGA in
 Windows and OS/2, including line draws, bit and pixel-block transfers, area
 fills, masking and X/Y addressing. Has an intelligent way to detect and co-
 exist with other XGA-2 cards, so multiple desktops like on the Mac may not be
 far away.  Since this is an architecture, its resolution and color depth 
 isn't fixed {IBM implements only 16-bit [65,536] color, while other 
 companies can have 24-bit color through IBM technical licenses}. Refresh 
 rates up to 75 Hz, ensures flicker free, rock solid images to reduce visual 
 discomfort, and is VGA compatible. Up to 1280x1024 on OS/2.
*some monitor types usable by Mac-See Mac section above for specific details.

Expansion
Both Mac & IBM {and maybe PowerPC}
SCSI: only external device expansion interface common to both Mac and IBM.
 Allows the use of any device: hard drive, printer, scanner, Nubus Mac II card
 expansion {Mac Plus only}, some monitors, and CD-ROM.  Normal {asynchronous}
 SCSI is 5 Mhz; fast {synchronous} SCSI is 10 Mhz.  Difference between these
 modes is mainly in the software drivers.
 Main problem:  there are a lot of external devices which are internal 
 terminated which causes problems for more then two devises off the SCSI port 
 {A SCSI chain is supposed to be terminated ONLY at the begining and end. 
 Any other set up causes problems for either Mac or IBM}. 
SCSI-1:  8-bit; 7 devices per SCSI controller.  asynchronous {~1.5 MB/s ave}
 and synchronous {5 MB/s max} transfers.  8-bit SCSI-2 is often mistaken for
 a faster version of SCSI-1 {see SCSI-2 for details}.
SCSI-2: fully SCSI-1 compliant. SCSI-2 mode - 10 devices per SCSI controller.
 8-bit SCSI-2 is implimented as a very fast SCSI-1 since it can run almost at
 full 8-bit speed using SCSI-1 hardware and software drivers which limit it
 to 7 devices. This results in it sometimes being mistakenly consitered part
 of SCSI-1.  16-bit and 32-bit SCSI-2 require different ports, electronics,
 and SCSI software drivers from SCSI-1.  32-bit SCSI seems to run only in
 synchronous mode, hence term 'wide and fast' SCSI.  Transfer speeds are 4-6
 MB/s with 10 MB/s burst {8-bit}, 8-12 MB/s with 20 MB/s burst {16-bit}, and
 15-20 MB/s with 40 MB/s burst {32-bit}.
Mac SCSI: asynchronous SCSI-1 built-in standard since the Plus.  Even though 
 Apple developed some specifications for SCSI controlers, the OS SCSI Manager
 needs to be rewritten to take full advantage of the features of both SCSI
 interfaces.  As a result present SCSI-2 Macs use 8-bit SCSI-2 as a fast 
 asynchronous SCSI-1.  Presently Centris 650 and the Quadras are the only Macs
 with a SCSI-2 controller chip built-in (Digital Review, Oct 21, 1991 v8 n33
 p8(1)) though they lack some other parts of the hardware, like the wide
 SCSI-2 port interface.  Since other Macs require a NuBus card to use SCSI-2,
 older NuBus Macs had a bottleneck due to the speed of the NuBus and CPU. 
 Rumor-some Cyclone Macs {June} will come with a wide & fast SCSI-2 port
 standard and have a rewritten OS SCSI manager.  Since SCSI is built-in
 overall cost is lower than for IBM and PC clone machines.
IBM SCSI:  SCSI-1 is not too wide spread yet, generally not bundled with 
 systems, except as add-on {EISA and VESA Local Bus adapters avalable}.
 Like the Mac, 8-bit SCSI-2 is used as a very fast SCSI-1 by most controllers
 out there.  Unlike the Mac, IBM has no exact SCSI controller specifications
 which results in added incompatibilities for SCSI.

Mac
Memory expansion: with a few exceptions Mac has used non-parity 30-pin 8-bit
 SIMM memory expansion since the Plus.  While 32-pin 9-bit parity SIMMs
 could be used in these Macs, only special IIcis could make use of the parity 
 feature {By convension both SIMM types are called 32-pin SIMMs}.  The IIfx 
 used 64-pin parity SIMMs.  The LC III, C610/650 and Q800 all use a new 
 72-pin SIMM that is accessable by 32-bits at a time and is used in IBMs.
 The Mac does a complete memory check at startup by writing/reading every
 memory location; if something is seriously wrong with a SIMM the Mac will
 not boot and give a sound chord indicating what the problem is.
 Since Macs made before Feb 15, 1993 managed memory baced on data path, SIMMs 
 had to be installed in pairs {16-bit} or in sets of 4 {32-bit}.  The Centris 
 650 and Quadra 800 eliminate this with a new memory management setup that 
 allows memory to be upgraded one SIMM at a time.  If the SIMMs are the same 
 size are used then the memory is 'interleaved' across the two SIMMs resulting
 in a 10-15% performance boost on RAM access (MacWorld Apr 93: 108-109).
Printers, ADBs, and modems: built-in interfaces standard.
Monitor interface and sound input: built-in on most present macs. 
PDS: Available in SE & all present non-Powerbook Macs. 16-bit {SE, Portable,
 LC, LC II, Classic line} and 32-bit.  Operates at CPU's MHz. Maximum through
 put: data path in bytes*CPU's MHz {Q700/900 & C650: 4 * 25Mhz = 100 MB/s;
 Q800 & Q950: 4 * 33 Mhz = 132 MB/s.  MPC601/60 should result in 66*64 = 
 3.84 GB/s max}.  Standardized with LC and 040 bus designs.  With an adapter
 one NuBus card can be used in IIsi and C610. 
 Problem: some cards have timing dependency which slows through put down.
NuBus Mac II: 32-bit, 10 MHz bus clock, 1-to-1 transaction/bus cycle ratio,
 and contiguous, hand-shake transactions at ~10-20 MB/s; theoretical peak:
 40 MB/s.  Built-in on all Modular Macs except the LC series, C610, and 
 Performa 400.  The SE/30 could be adapted to use this and there was even a 
 Mac Plus SCSI NuBus.  Supports every possible expansion from CPU to Ethernet 
 to DMA.
NuBus 90: NuBus Mac II back compatable. 20 MHz bus clock, avg throughput:
 ~30MB/s; burst mode: 80 MB/s.  Future card designs will be 7" instead of
 the old 12" and use less energy.
QuickRing:  A peer-to-peer bus to be used in parallel with NuBus 90.  Apple's 
 local bus - "architecture is identical to that of the VL-Bus, since the
 high-speed PDS interconnect taps directly into the CPU's signal lines and
 bypasses the slower NuBus control logic." (Byte 10/92:128).
 Though put: 350 MB/s (Byte 10/92:128), Burst mode: 3.2 GB 
 (InfoWorld 5/03/93:6). In development.
CPU expansion: handled either through the PDS or the NuBus.  Unlike PDS,  
 Nubus CPU cards {example-Radius Rocket} allow use of multiple processors at 
 the same time.  This is like having two or more Macs in the same box able to 
 dual task or joinly process depending on the card or software involved {Each 
 NuBus card needs its own memory but most NuBus cards of this type come with 
 8 MB RAM SIMMs on the card standard}.

IBM
Memory expansion:  parity SIMMs, non-parity SIMMs {some newer models do a Mac-
like SIMM memory check}, or a dozen or so different types of memory boards.

HD Interfaces {limited to hard drives by design or lack of development}: 
MFM:  Modified Frequency Modulation, RLL:  Run Length Limited
 Obsolete interfaces only used with old small [ 60mb] hard drives.
IDE:  Integrated Device Electronics 
 Asynchronous {~5 MB/s max} and synchronous {8.3 MB/s max} transfer.
 currently the most common standard, and is mainly used for medium sized 
 drives. Can have more than one hard drive. 
ESDI:  Enhanced Small Device Interface
 ~1.25MB/s throughput. generally considered better interface than SCSI-1 in
 many ways but not common enough for practical consideration.  Outside of
 hard drives, device choices are very limited compared to SCSI-1. 

BUS interfaces
{New 'plug and play' ISA and EISA compatable cards may have problems working 
with old cards (PC Week 03/08/93).}
ISA
 8 & 16-bit interfaces common. Has 24-bit data path limit {produces a 16 MB
 limit for which there are software workarounds} (PC Mag 4/27/93:105).
 1.5 MB/s (Byte 3/93:132).  Uses edge-triggered interrupts, can't share them,
 hence comes the IRQ conflict.  Limited busmastering capabilities, some cards
 aren't bandwidth limited {COM  ports, LPT ports, game ports, MIDI card, etc.}
 while others are {video and disk controllers}.  Dominant factor, but it's
 showing its age.  Most ISA motherboard designs are 16-bit
 (PC World Feb 1993: 144-5)}.  
MCA {Micro Channel}
 IBM's 16 and 32-bit bus; "allows use of more than one CPU in a computer" 
 (DCT) and anything can talk to anything, as fast as the two components 
 involved can handle it. Never took off because it was incompatible with ISA 
 and EISA.  Planned to be IBM PowerPC 601's bus interface (Carl Jabido).
EISA {NuBus Mac II closest Mac equivalent}
 32-bit, 8.33 MHz, burst mode: 33 MB/s.  It also has the ability to 
 self-configure cards like MCA and allows multiple bus masters, sharable 
 interrupt and DMA channels and multiple CPU use.
EISA-2
 Advantages over EISA unknown {NuBus 90 speeds suspected}.
VESA Local Bus: VLB {Sometimes mistakenly refered to as PDS}
 Local Bus standard. Runs at CPU clock rate,  Burst modes: ~130 MB/s{32-bit}
 250 MB/s{64-bit} (Byte 10/92:128).  Limited to three slots but allows bus 
 mastering and will coexist with either ISA or EISA. Consitered ideal for 
 video and disk I/O.  DELL has filled a claim that this violates one of
 their patents (Mel Martinez).
QuickRing: Apple's faster {350 MB/s burst} version of Local Bus architecture
 (Byte 10/92:132).  Might show up in some IBM and PowerPC machines
 (Byte 10/92:132-133). In development.
PCI
 Intel's version of Local Bus that is intended to totally replace 
 ISA/EISA/MCA.  In development.

OSes {assumes full installation [print drivers, fonts, Multifinder, etc.]
and multiple application use.}
Mac
512K to 1MB of OS and hardware commands have been put into ROM.  This allows 
Apple to control its machine by putting key hooks for the Mac OS {QuickDraw, 
menu commands, print, mouse, SCSI & sound drivers, etc} in ROM, which require 
clone makers to use the ROM chip or read ROM on to disks {Which requires 
access to the proper Mac due to improvements and changes in ROM chips; Plus vs
Classic for example.}  With key hooks for the OS interface in ROM, programers 
do not have to worry as much whether the disk OS has the necessary hardware 
commands or that those commands are consitant and therefore can write smaller 
programs.  This also allows Apple greater control over hardware-software 
standards, allows the disk OS to be smaller and, with some of the tookbox 
command code in ROM, lower RAM requirements then a totally disk based OS.  
Macs use 'Masked ROM' which is as fast as DRAM (Jon Wtte).
6.0.7: Single program usage base requirements: 1 MB and DD floppy, 
 cooperatively-multitasking base requirements: 2 MB and HD floppy.  
 Features a GUI, cooperative-multitasker [MultiFinder], standard program 
 interface, & standard stereo sound support [snd]. Network receiving part of 
 AppleShare software is bundled with the OS. This 24-bit OS has a 8 MB RAM
 barrier. Some third party products allow 14 MB of Virtual Memory as long as 
 real RAM is below 8 MB.
6.0.8: 6.0.7 with 7.0.0 print drivers.
6.0.8L:  System 6 for some Macs that require System 7.0.X. Rarely used.
7.0.X: Base requirements: 2 MB, 40 MB hard drive, and 68000; De-facto standard
 to run all features well: 4 MB, 80 MB hard drive, and 68030 {lowest present 
 non-portable Mac configuration}.  Using up to 10.08 MB of hard disk space
 {EVERYTHING on system disks} this 24 and 32-bit OS has 6.0.7 features plus
 program linking within and between computers [IAC], built-in server
 capabilities {Filesharing can be used by older OSes using AppleShare Client
 software and can be accessed by 10 macs max; 4-5 is more speed practical, IAC
 requires 7.X}, Virtual Memory in machines with MMU{1.6 times real RAM for
 least noticeable IIsi speed degradation}, drag and drop, QuickTime & built-in
 TrueType support.  Supports sound input [AIFF and snd formats] for most
 present machines.  Can access up to 1 GB of true RAM and 4 GB of virtual
 memory.  To use real RAM beyond 8 MB it must be in 32-bit mode; older
 machines require 'Mode 32' extension.  Apple's last 'free' OS.
7.1.0: 7.0.1 with WorldScript support, speedier, and less RAM usage than 
 7.0.X (MacWeek 9/14/92; PC Week 9/7/92). To run in 32-bit mode on older
 machines this requires the 'Mode 32' or '32-Bit Enabler' extension.
 Thread Manager extension allows preemtive multitasking for programs
 written for it.
 Marks the start of Apple selling its Mac OS instead of allowing free
 upgrades: Bundled with new machines, $49 for 7.0.X upgrades, $99 otherwise.
 [The installer has a bug that when upgrading it may keep some old system 
 fonts from the previous system inside the system file.  This can eat up any 
 RAM benefits and cause other problems.  Apple itself recommends removing all 
 fonts from the system file or doing a clean install.]
A/UX 3.0 [UNIX]: Needs 8 MB RAM {12-20 MB suggested}, 160 MB hard drive, and 
 a 68030 or 68040 equivalent to run.  This 32-bit preemptive multitasking OS 
 is large due to being UNIX and needing translators between it and the Mac 
 ROMs.  Price: $709.
Note: sound output was supported in OSes 3.2 to 6.0.5 by many formats 
including the following:  snd, WAVE, ASND, FSSD, QSSN, SMSD, SOUN, dc2d, and 
DCFL.  In 6.0.7 the sound manager was optimized for the sound standards 'snd' 
and AIFF which causes some playback problems for the other formats, though 
most still play correctly.

IBM
 Machines have little GUI code, data, and hooks present in hardware for 
programmers to work with, so most of the coding must be provided in the OS.  
Since hard disks were slow the disk OS code is read into RAM.  In addition, 
what little ROM code there is also read into RAM {a process called Shadow ROM}
 
This results in faster implementation since RAM is faster then PROMS or 
EPROMS.  Having most of the OS code on disk has the advantage of being able to
better optimize the code given a certain piece or collection of hardware which
is harder with a ROM based system due to the 'patches' needed.  In addition it
reduces size of patches if a major revision of the hardware support is needed.
Side note:  The FTC charged that MicroSoft formed a OS trust by not providing 
all feature documentation for its OSes to developers outside MS and designing 
its Windows and DOS apps to fail under OS/2 ("Undocumented Windows") and 
"There is deliberate code in [Windows] NT Beta which causes the install to 
abort if OS/2 Boot Manager is present" (Gregory Hicks, Info-IBMPC Digest V92 
#201).  Due to a conflict of intrest by one member the vote of the FTC 
judicial council for action against Microsoft was a tie which resulted in no 
action.  Rumors-the FTC will presue the matter, likely to the point of 
choosing a new member or whole new council.  In addition the government has 
turned down Microsoft's trademark of "Windows" which would allow it to charge 
a fee for developers using the name (PC Week 03/08/93).
MicroSoft OSes
DOS 5.0: Conventional Memory mode is limited to either 640 K {DOS's own memory
 manager} or 1 MB {third party memory managers}.  XMS allows up to 16 MB but
 is usable only by certain programs.  Protected Mode Interface (DPMI)
 compliant programs running in 32-bit Protected Mode [386dx] also allow 16 MB.
 Contains the DOS 4.0 GUI shell.
DOS 6.0: DOS 5.0 with the added features of a disk defragmenter, debugger for
 the CONFIG.SYS file {the built-in file compresion was removed due to hardware
 conflicts}. It needs a $80 module for networking.  Cost: $50 through 5/93,
 after that $129.99 (Byte April 1993:44-46).
DOS 7.0: 32-bit DOS. In development (PC Week 04/05/93).
Windows 3.0: Runs on top of DOS.  Breaks 640K and 1 M barriers but still uses
 DOS file structure.  Base requirements: 1 MB, floppy and 286; to run well
 2 MB, hard drive, 386sx and fast display adapter {> 8-bit}.  Has
 Mac's QD equivalent called Windows GDI [Graphics Device Interface].
 This does not have consistent application interfaces {Like early (1984-1985)
 Mac programs} nor a very large program base {compared to DOS} and
 still tends to slow the machine down (Info-IBMPC Digest V92 #186) with speed
 more dependent on the display adapter then on the CPU (Bill Coleman).
 Window programs tend to be disk and memory hogs compared to their DOS
 counterparts (Byte April 1993:98-108).
Windows 3.1: A faster version of Window 3.0 with better memory managment. Base
 requirements 2 MB, hard drive and 286; to run well 4 MB, hard drive, 386sx. 
 Apple plans to release its print drivers for this (PC Week 12/28/92).
Windows for Workgroups:  To run well: 4 MB RAM and 386dx (PC World
 Feb/93:160). Intermediary between Win 3.1 and Windows NT.  It is basically
 Windows 3.1 with built-in peer to peer networking support.
Windows NT:  Beta requirements: ~50 MB of disk space [including the swap
 file], and 12 MB RAM {Betas are notorious for RAM usage especially when
 interacting with program compliers, hence 24 MB reports}.  Released version: 
 8 MB RAM planned, but Gates himself now recommends 16 MB (PC Week 04/15/93).
 This 32-bit OS has protected mode multitasking, multithreading, symmetric 
 multiprocessing, a recoverable file system, and 32-bit data GDI.  Has
 built-in OSF DCE compliant networking and can handle up to 4 GB RAM.
 MicroSoft moved up the final version releace date to May (PC Week 03/15/93)
 from Oct/4th quarter 93 (PC Week 09/28/92) {MS is now just saying
 'Summer'}. Windows upgrades: $295, $495 otherwise (PC Week 03/15/93).
Other OSes
PC-DOS 6.0: IBM's version of DOS 6.0.  It runs Windows much faster then DOS 
 6.0 due to faster file I/O and video handling (InfoWorld Feb 1, 1993).
DR DOS 6.0: same as DOS 5.0 with some extras {like built-in data compression} 
 and memory management enhancements. Still has 640K/1MB barrier.  A later 
 version {Novell DOS} of this may use a version of the Mac finder and Apple 
 file management system (PC Week 12/14/92; PC Week 05/03/93).
OS/2 2.1: Base requirements- 4 MB RAM, 40 MB hard drive, 386sx; to run well-
 8-16 MB RAM, 60 MB hard drive {uses 17-33 MB}, and 386dx CPU. This 32-bit
 multithreaded, multitasking OS with UNIX-like features can address up to
 4 GB RAM but on ISA systems using DMA {Direct Memory Access} ALL memory above
 16 MB RAM is used a fast swap file.  Windows programs run faster on this than
 DOS and Multimedia support built-in (BYTE June 1993: 193)  IBM plans to use
 Taligent's OOPS in future versions of this.
AIX:  IBM's UNIX system, planned to be a subset of PowerOpen and Taligent OS.
NeXTStep 3.1: Base requirements{beta}-8 MB {grayscale}/16 MB {16-bit color},
 120 MB hard drive, 486sx. Suggested-12 MB {grayscale}/24 MB {16-bit color},
 486sx.  Object-oriented Mach(UNIX)-based microkernal GUI OS with built-in
 multi-architecture binary support, preemptive multitasking, multithreading,
 virtual memory, multimedia e-mail, on-line help, Display PostScript Level 2,
 networking support {NFS 4.0, Novell, Ethernet, Token Ring}, Pixar's
 Interactive- and Photorealistic- 3D RenderMan, Pantone color support,
 and Object Links. Can read, write, and initialize Mac and IBM disks.
 Final version due May 25, 1993 (All info from 1993 NeXT, Inc. literature
 provided by Dayne Miller)
Solaris OS for x86: a SunSoft port.  A 32-bit OS with symmetric 
 multiprocessing and multithreading, built-in networking capabilities with 
 tools to allow remote configuring and adminstration features, and a
 communication package.  Client: $795,  50 users server: $1,995, 1000s users
 server: $5,995.  Developer kits-software: $495, hardware: $195.
Mac 7.1 [working name: Star Trek]:  Apple had System 7.0 running off Intel 
 chips and is looking at making a 7.1 version available for IBM 
 (MacWeek 03/22/93; PC Week 05/03/93). Will have QuickDraw emulator with
 QuickDraw GX and AppleTalk-NetWare support (MacWeek 04/26/93) 
 Presently planned to run on 86, 486, and Pentium; Mac programs will have
 to be ported (MacWeek 04/26/93).  Viewed as Novell's answer to Windows NT. 
 The complexity of PC hardware set ups is one reason for slow progress.

PowerPC OSes
PowerOpen [A/UX 4.0]: Planned base requirements:  68030, 8 MB RAM, 80 MB hard
 drive (MacWeek 4/19/93).  This 32-bit preemptive multitasking OS is planned
 to run on PowerPCs and 68030/40 Macs (MacWeek 7/13/92).  The Mac toolbox is
 planned to be a part of this OS architecture (PC Week 03/08/93).  Intel
 compatibility uncertain (See Mac 7.1 and AIX above).   Rumor-ahead of
 schedule; COULD be out by mid 1993 and be IBM PowerPC 601's OS.
Pink [Taligent OS]: Expecting delivery in 1994 (Wall Street Journal 1/12/93). 
 May have some parts shipping inside OS/2 and AIX in 1993; PowerOpen and
 later Mac OS will also contain parts of this OS (MacWeek 01/25/93).
Solaris OS:  Sun Microsystems Inc UNIX OS version for Power PCs in 1994
 (MacWeek 04/05/93).  One of the few OSes to directly state that it will run
 Windows/DOS programs.  See IBM OS section for details
System 7.x; suppossed to be the first OS for the PowerPC Mac.
NeXTStep: possible port see IBM OS section for details.
Windows NT: Possible port (MacWeek 04/05/93).  See IBM OS section for details.
WorkPlace OS: OS/2 for the PowerPC with Pink features. Beta due out in May.

OS Number Crunching (Mel Park)
Mac
 Arithmetic is done in a consistent numerical environment {SANE or Standard 
Apple Numerics Environment}. Floating point numbers are 96 bits long when an 
FPU is present and 80 bits otherwise. Exceptions, such as dividing by zero or 
taking the square root of a negative number, do not cause an abort but are 
handled in a logically consistent manner. 1/0 produces the internal 
representation for infinity (INF).  1/(1/0) produces zero. The above treatment
of 1/(1/0) occurs in an FPU-equipped machine even when SANE is bypassed and 
the FPU programmed directly.

IBM
 Floating point numbers are 80-bits with a hardware FPU, 64-bits when 
emulated.  The way they are handled is dependent on the coding of whatever 
compiler or assembler was used for a program. On older DOS complilers 
exceptions could cause program aborts; 1/0 and 1/(1/0) would abort to the DOS 
prompt at the point where they occured.  Most present compilers handle this 
better.  Result: there is little consistent handling of numbers between DOS, 
Windows and OS/2 programs nor between programs for just one OS.

Networking [Includes printing]
WYSIWYG printing can be a problem with either Mac of IBM machines especially 
if one sends TrueType fonts to a older style PostScript printer.
Mac
Hardware: Built-in LocalTalk network port and a built-in printer port.  
LocalTalk has moderate speeds (230.4 Kb/s) requires special connectors for 
each machine ($15 and up) and can be run off of either the printer port {to 
include very old macs} or the network port {standard today}.  Built-in 
Ethernet is becoming common but many older Macs require a PDS or Nubus card at
about $150-$300 for each machine.  These cards provide three connectors and 
transceivers {thick, thin, and 10BaseT} for Ethernet.
The Macintosh Quadra family and some Centris models include Ethernet interface
on motherboard, with transceivers available. TokenRing has been a network 
option since 1989.
Software: AppleTalk {the suite of protocols} standard with Mac OS, which can 
use variety of media types.  AppleShare client software included with the OS 
as well and can connect to file servers such as Novell Netware, 3Com 3+Open, 
Banyan Vines, DEC Pathworks, Apple's AppleShare servers, System 7 File Sharing
machines, and AFP servers running on variety of UNIX hosts.  MacTCP allows 
typical TCP/IP communications (telnet, ftp, NFS, rlogin).  A later version 
will have Unix X/Open Transport Interface (XTI) built-in by the end of 1993 
(MacWeek 04/12/93).  Third-party software to connect to NFS servers.  DEC 
Pathworks provides DECnet support.  Peer-to-peer file sharing software 
built-in to System 7.1 (See OS section).  Full server software is extra. 
Printing requires connection of the printer and the printer being selected in 
the chooser.  Changing printers is by selecting a different name in the 
chooser.  The same is true of connecting to servers.
Printing bugs:  Monaco TrueType font is different then the screen bitmap font.
 {QuickDraw QX is suppossed to fix this and similar problems.}

IBM  
Hardware: LocalTalk [not widely used], Ethernet,  and TokenRing.
Software: Novell Netware, Banyan Vines, DECNet, Windows/Work Groups, AppleTalk
protocols, and AppleShare {subset of AppleTalk}.
Each of the MS-DOS networking schemes are, in general, totally incompatible 
with the others. Once you have chosen one, you are pretty much locked-in to 
that product line from then on.  Windows/Work Groups is a little more 
forgiving and removes some of this problem.  Novell Netware is the biggest, 
{~80 percent of the corporate market.} and in general is more powerful and 
offers better control/management/security than AppleShare, but it's also more 
complex to set up and manage.  This will change due to the use of the Mac 
finder and file management system by Novell (PC Week 12/14/92; PC Week 
12/28/92; MacWeek 3/22/93).
Printing {Very OS dependent}
DOS: If it's a single user, then you plug the printer into the parallel port, 
 and don't worry about it {Tweeking may be needed with poorly written 
 software}.  Network Printing is not controlled by the system, but is mostly 
 implemented by the actual program, therefore performance varies from one 
 software program to the next.
Windows 3.x: supports standard drivers and can do a good job of showing "jobs"
 in the print queue, but it always lists printers as "active"... even if they 
 are not.  This becomes a problem if there are several incompatible printers 
 on the same net, because there's no way for software to reliably determine 
 which printer is active right now.  Windows for Workgroups is more Mac-like 
 and intelligent about this.
OS/2: Mac-like; the os deals with printers, with apps making calls to the OS.
Printing bugs: due to poor programing some programs for all the above OSes do 
not have WYSIWYG printing.  This is the fault of the programs in question and 
not that of the OS involved.

Price issue: This is very dynamic with Mac providing more build-in features 
than IBM and IBM being more 'get only what you need' then Mac and price wars 
by both worlds.
The IBM machines' modualar nature prevents any kind of true hardware 
standarization, which in turn requires OSes and programs to be very complex to
handle ALL the variation in hardware.  When one adds all the standard Mac 
hardware features to an IBM {built-in input/output sound support, SCSI, PDS,  
built-in monitor support, built-in networking, standard mouse interface, and 
NuBus 90 in higher machines} the Mac tends to be cheaper then an equivalent 
equipted IBM machine {Especially since some IBM monitors can be used with Macs
which cuts some more of the Mac's cost (MacUser Aug 1992:158-176)}.
 Some Mac prices, using some of the info in this sheet and MacUser April 1993:
All Macs below come with a PDS slot, VRAM, and SCSI-1 built-in.  Except where 
noted, monitor is extra and a built-in monitor interface is provided {no card 
needed except for 24-bit color display}.
Color Classic:  $1,389 - 030/16 MHz with 16-bit data bus {~386sx/20 MHz 
equivalent}, 4/80, FPU socket, and built-in monitor.
LCIII: $1,499 - 030/25 MHz {~386dx/33MHz equivalent}, and 4/160.
Centris 610: $2,899 - 68LC040/20 MHz {Depending on the program ~486sx/40 or 
~'486dx2sx'/20[40] MHz equivalent}, 8/230, built-in ethernet, 300i CD-ROM, a 
PDS/NuBus 90 slot and VRAM for 16-bit color.
Centris 650: 040/25MHz {Depending on the program ~486dx/50 MHz or 486dx2/50 
MHz equivalent} with a PDS and 3 NuBus 90 slots. $3,189 {ethernet, 8/80}; 
$3,559 {ethernet, 8/230}; $3,999 {ethernet, 8/230, CD-ROM, VRAM for 16-bit 
color}

These are the facts as they were known to me on 5/20/93 and may be changed by 
new developments, announcements, or corrections.  Corrections to the 
information are welcome.
Please email corrections to 
CompuServe ID: 72130,3557
AOL: BruceG6069
Internet:  bgrubb@dante.nmsu.edu

Bibliography notes
'Info-IBMPC Digest' back issues are available from wsmr-simtel20.army.mil in 
directory PD2:<ARCHIVES.IBMPC>
'Dictionary of Computer Terms 3rd ed.' (ISBM 0-8120-4824-5)
bcoleman@hayes.com (Bill Coleman)
matt@wardsgi.med.yale.edu (Matt Healy)
cj00+@andrew.cmu.edu (Carl B Jabido)
fj05+@andrew.cmu.edu (Faisal Nameer Jawdat)
jokim@jarthur.claremont.edu (John H. Kim)
lamont@catfish16.rtsg.mot.com (Bradley Lamont)
mem@jhufos.pha.jhu.edu (Mel Martinez)
dayne@u.washington.edu (Dayne Miller)
mpark@utmem1.utmem.edu (Mel Park)
d88-jwa@nada.kth.se (Jon Wtte)
nan@matt.ksu.ksu.edu (Nan Zou)

Final note: Since there is NO comp.sys.ibm.pc.advocacy group this has been 
posted to the closest relevent groups {comp.os.ms-windows.advocacy, 
comp.os.os2.advocacy, and comp.sys.ibm.pc.misc}.  Also since some Mac vs IBM 
articles have been showing up in comp.sys.mac.hardware I have included that 
newsgroup in the posting. {Don't site the comp.sys.mac.* FAQ as a reason not 
to post to comp.sys.mac.hardware, since the FAQ itself does not follow 
internet guidelines, especially the de-facto "[all] the FAQs for a newgroup 
hierarchy should be posted to ALL newsgroups in the hierarchy" standard.}

"Eliminate the impossible and what ever remains, no matter how improbable,
is the truth" -- Sir Arthur Conan Doyle through Sherlock Holmes in The 
Adventure of the Beryl Coronet, The Adventure of the Blanched Soldier, Sign of
Four and The Adventure of the Bruce-Partington Plans.

"The Computer is your friend"--Parinoia RPG
