Brian’s Mac Monitor Summary

Brian's Mac Monitor Summary        [last revised: 1 December 2006]

This summary is concerned only with analog graphics signals, not digital.

The newest revision of this document is always available as a link from URL    Actually no, that's a 21st-century lie.

Send corrections to:
Part0:  Legal Mumbo-Jumbo

This document (c)2006 by Brian Cole ( The information
contained herein is believed to be accurate but is not guaranteed. Use
at your own risk.

Archive sites may maintain a copy of this Summary so long as they allow
free access from any site worldwide (no domain restrictions, no reverse
DNS lookup tests). Individuals may maintain a copy of this Summary for
their own personal use. This Summary may not be sold or reprinted without
explicit permission from the author, though permission will usually be
granted in exchange for one copy of the magazine/CD-ROM/newsletter/whatever,
so don't be afraid to ask.

In any case, this document must remain in its original mono-spaced ASCII
form.  No compression (.Z, .gz, .sit, .cpt, .sea), expansion (.hqx, .uu),
translaton (.rtf, .etx, .html, .pdf, .doc), or other alteration is allowed.

Part1:  Sense Codes

setting   pin04    pin07    pin10     available resolutions
--------  -------  -------  -------  -----------------------------------------
rgb12"    pin11    open     pin11     512x384
rgb14"    pin11    open     open      640x480  (aka. rgb13", mono12")
rgb16"    pin10    open     pin04     832x624
rgb19"    pin07    pin04    open     1024x768
rgb21"    pin11    pin11    pin11    1152x870

multi15"  pin11    pin10    pin07     640x480, 832x624
multi17"  pin11    anode    cathode   640x480, 832x624, 1024x768
multi20"  pin11    cathode  anode     640x480, 832x624, 1024x768, 1152x870
                                                        1280x960, 1280x1024

rgb15"    open     pin11    open      640x870  (aka. color portrait)
mono15"   open     pin11    pin11     640x870  (aka. full-page, portrait)
mono21"   open     open     pin11    1152x870  (aka. two-page monchrome)

VGA/SVGA  open     pin10    pin07     640x480, 800x600, 1024x768

NTSC mon  pin11    pin11    open      512x384-under, 640x480-over
NTSC enc  cathode  07&anod  10&anod   512x384-under, 640x480-over
PAL mon   07&cath  04&cath  anode     640x480-under, 768x576-over
PAL enc   07&10    04&10    04&07     640x480-under, 768x576-over

  notes:  * Not all Macs support all modes.
          * If more than one resolution is supported, choose among them
            via the "Monitors" control panel (but read the note above).
          * Somebody tell me how Apple's MutipleScan 14" display signals
            that it can do 640x480@67 and 800x600, but not 832x624@75.
          * "anode" and "cathode" denote a diode bridging the pins.
            The ringed end is the cathode.  (Radio Shack part 276-1122)
          * The 1280x___ resolutions have been added to the list of supported
            resolutions list for the multiscan20" sense code, but this is
            speculation on my part, though it does explain experimental data.
          * In the absence of additional conversion hardware, NTSC and
            PAL signals are black&white only.
          * I don't know what the difference between Monitor ("mon") and
            Encoder ("enc") modes is for NTSC and PAL, so please clue me in.
          * Tell me why the rgb21" and mono21" are considered different
            modes but rgb14" and mono12" are considered the same mode.
          * Some Apple video hardware supports a different sense pin
            combination for 15" portrait displays with non-Apple timings
            (If you know about this, please clue me in).

Part2:  Refresh Rates

Specs for the various resolutions supported by Apple hardware.

resolution         Vert Hz    Horiz KHz    Dot Clock MHz
----------------   -------    ---------    -------------
1280x1024 Apple     75           ?            ?    (see Part1 note)
1280x 960 Apple      ?           ?            ?    (see Part1 note)
1152x 870 Apple     75.08       68.7        100
1024x 768 Apple     74.93       60.24        80
 832x 624 Apple     74.55       49.7         57.63
 640x 870 Apple     75.08       68.9         57.2832
 640x 480 Apple     66.67       35.0         30.24
 512x 384 Apple     60.15       24.48        15.6672

 640x 870 non-Apple  ?           ?            ?    (Radius?, RasterOps?)

1280x1024 VESA      75           ?            ?
1280x 960 VESA      75           ?            ?
1024x 768 VESA      75           ?            ?
1024x 768 SVGA      72           ?            ?
1024x 768 VESA      70          56.5          ?
1024x 768 VESA      60          48.8         64
 800x 600 VESA      75           ?            ?
 800x 600 VESA      72          48.1          ?
 800x 600 VESA      60          37.9          ?
 800x 600 SVGA      55.98       35.16        36
 640x 480 VGA       59.95       31.47        25.175

NTSC                59.94       15.7         12.2727
PAL                 50.00       15.625       14.75

  notes:  * There are 4 different 640x480 modes -- Apple, VGA, NTSC, and PAL.
          * Dot clock is the rate at which pixels must be sent to the monitor.
          * NTSC and PAL are interleaved.

Part3:  Pinouts

First, here are the connectors.  These are for male connectors, the pins are
pointing towards your eyes.  Female connectors are mirror images of these.

    DA-15                                 DE-15
    ,--------------------------------.    ,-------------------------.
    \ 01  02  03  04  05  06  07  08 /    \    01  02  03  04  05   /
     \                              /      \ 06  07  08  09  10    /
      \ 09  10  11  12  13  14  15 /        \  11  12  13  14  15 /
       `--------------------------'          `-------------------'

    14-pin PowerBook                      DE-9
     /==-==-==-==-==-==-==\               ,-------------------------.
    / 01 02 03 04 05 06 07 \              \  1    2    3    4    5  /
    |                      |               \                       /
    | 08 09 10 11 12 13 14 |                \   6    7    8   9   /
    +-==-==-==-==-==-==-==-+                 `-------------------'

                           HDI-45 AudioVision
                           / ,------------------------------------. \
                           | | 35  36  37 38 39 40 41 42 43 44 45 | |
                           | `-.       28 29 30 31 32 33 34     ,-' |
                           |   |:: 19  20 21 22 23 24 25 26 27  |   |
                           | ,-'       12 13 14 15 16 17 18     `-. |
                           | | 01  02  03 04 05 06 07 08 09 10 11 | |
                           | `------------------------------------' |

     Mini-VGA (Hosiden TCX3143)    DVI [Pin C5 is the fins between C1/C2/C3/C4.]
       ,--------------------.      +--------------------------------+
      / 01 03 05 07 09 11 13 \     | C2|C1  08 07 06 05 04 03 02 01 |
     |                        |    | --+--  16 15 14 13 12 10 09 08 |
     |   02 04 06 08 10 12 14 |    \ C4|C3  24 23 22 21 20 19 18 17 /
     +------------------------+     `------------------------------'

                            ADC (Apple Display Connector) [Pin C5 is the fins.]
                             / C2|C1  10 09 08 07 06 05 04 03 02 01 \
                            (  --+--  20 19 18 17 16 15 14 13 12 11  )
                             \ C4|C3  30 29 28 27 26 25 24 23 22 21 /

  Mac    SVGA   VGA                                                                 mini-  TTL
  DA-15  DE-15  DE-9   DVI-A   ADC                                    HDI45  pb-14  VGA    DE-9
  -----  -----  -----  -----  -----                                   -----  -----  -----  -----
  shell  shell  shell  shell  shell  safety ground (note 1)           shell  shell  shell  shell
    02     01     1      C1     C4   red signal                        27     14     05      3
    01     06     6      C5     C5   red ground                        26      7     04
    05     02     2      C2     C2   green signal (note 2)             11      4     07      4
    06     07     7      C5     C5   green ground                      10     11     06
    09     03     3      C3     C1   blue signal                       45      8     09      5
    13     08     8      C5     C5   blue ground                       44      1     14
    04     11                        sense pin 0 (note 5)               8     13
    07    (12)                       sense pin 1 (notes 5, 4)           9     10
    10     04                        sense pin 2 (note 5)              18      9
    03                               composite sync signal (note 3)    34     12
    15     13     4      C4     C3   horizontal sync signal            42      2     03      8
    14     05            15     C5   horizontal sync ground (note 3)   43      3
    12     14     5      08     10   vertical sync signal              33      6     02      9
           10            15     C5   vertical sync and DDC ground      43
    11    (05)    9                  ground (note 6)                           5     01,12   1,2
           12            07     09   DDC data                          28            10
           15            06     19   DDC clock                         29            11
           09            14          +5V                               13            08
                         16          HPD or cable detect (note 7)                    13
                                     monitor ID                       31,32,41
                                     intensity                                               6
                                     monochrome signal                                       7

  notes:  * I'm unsure how gender terms apply to the flat 14-pin PowerBook
            connector. Pictured is the connector that would be inserted
            into the back of a PowerBook. Also unsure of mini-VGA (TCX3143).
          * Mac pin 08 is not used (reserved for a fourth sense pin??), and
            neither were SVGA pins 09/15 before DDC was introduced in ~2004.
          * Some pinouts for the rare 9-pin VGA connector (the 15-pin one
            is typically used instead) reverse the roles of pins 4 and 5.
            I've seen DE-9 VGA monitors both ways.
          * DVI supports both analog and digital signals, but only pins for
            analog signals are listed here. DVI-D lacks some of these pins.
            ADC similarly supports analog, digital, USB, and 100W power.
            The 45-pin "AudioVision" connector supports analog graphics, ADB,
            audio out (analog stereo), audio in (analog stereo), and S-video.
          * TTL signals (EGA/CGA) are not compatible with the analog signals
            used by Mac/SVGA/VGA.  Don't blindly try to convert between them.
          * EGA has "secondary" r/g/b lines on pins 2/6/7. What are they?
        (1) also signal ground for NTSC and PAL
        (2) also monochrome signal (VGA/NTSC/PAL); also sync-on-green
        (3) mac-to-vga adapter sync signals:
              mac14-vga10, mac12-vga14, mac15-vga13 (or sometimes mac03-vga13)
        (4) Prior to DDC: Ground sense0 for monochrome. Ground sense1 for
            color. Ground sense2 for resolutions of 1024x768 or higher.
        (5) See part1 for Mac sense codes.
        (6) the ground for sense pins and signals without specified grounds
        (7) Connect mini-VGA pin 13 to ground for the cable to be recognized.
            DVI displays put various voltages on the HPD (Hot Plug Detect) pin.
            DVI-to-SVGA adapters sometimes ground it, sometimes wire it to +5V.


Brian’s Mac Serial Port Summary

Brian's Mac Serial Port Summary    [last revised: 1 September 1998]

The newest revision of this document is always available as a link from URL    Actually no, that's a 21st-century lie.

Send corrections to:
Part0:  Legal Mumbo-Jumbo

This document (c)1998 by Brian Cole ( The information
contained herein is believed to be accurate but is not guaranteed. Use
at your own risk.

Archive sites may maintain a copy of this Summary so long as they allow
free access from any site worldwide (no domain restrictions, no reverse
DNS lookup tests). Individuals may maintain a copy of this Summary for
their own personal use. This Summary may not be sold or reprinted without
explicit permission from the author, though permission will usually be
granted in exchange for one copy of the magazine/CD-ROM/newsletter/whatever,
so don't be afraid to ask.

In any case, this document must remain in its original mono-spaced ASCII
form.  No compression (.Z, .gz, .sit, .cpt, .sea), expansion (.hqx, .uu),
translaton (.rtf, .etx, .html, .pdf, .doc), or other alteration is allowed.

Part 1:  Connector Pinouts

First, here are the pinouts.  These are for male connectors, the pins are
pointing towards your eyes.  Female connectors are mirror images of these.

  miniDIN-8           DB-25
    ,----v----.       ,----------------------------------------------------.
   /           \      \ 01  02  03  04  05  06  07  08  09  10  11  12  13 /
  |  6   7   8  |      \  14  15  16  17  18  19  20  21  22  23  24  25  /
  |             |       `------------------------------------------------'
  | 3   4     5 |
  |             |     DE-9
  |_   1   2   _|     ,---------------------.
    |         |       \  1   2   3   4   5  /
    `--.___,--'        \   6   7   8   9   /

                                 ibm       apple(early macs and LaserWriters)
   pin#     DIN-8     DB-25      DE-9      DE-9
  ------    ------    ------    ------    ------
  shield     gnd       gnd       gnd       gnd
      1      HSKo      gnd       DCD       gnd
      2     *HSKi      TD        RD        +5v
      3      TxD-      RD        TD        SG
      4      SG        RTS       DTR       TxD+
      5      RxD-      CTS       SG        TxD-
      6      TxD+      DSR       DSR       +12v(HSKo)
      7      GPi       SG        RTS      *HSKi(DSR)
      8     *RxD+      DCD       CTS      *RxD+
      9                +dcv      RI        RxD-
     10                -dcv (DC test voltage) [DCE->DTE]
     11                QM
     12                (S)DCD
     13                (S)CTS
     14                (S)TD, NS, [fault on IW1]
     15                TC [DCE->DTE]
     16                (S)RD, DCT
     17                RC
     18                DCR
     19                (S)RTS
     20                DTR
     21                SQ
     22                RI
     23                data rate selector
     24                (TC) [DTE->DCE]
     25                busy
      G  +5v (between pins 4 and 5; GeoPort only)

  *HSKi can also be used for External Clock
  *ground RxD+ to SG to emulate RS232 (leave TxD+ floating)

Part 2:  Useful Cables

RTS/CTS control flow cable  (DCE device must be set to ignore drops in DTR.)

             Din-8           DB-25 (DCE)
  -----------------          ------------------
  HSKo       1        ---->  4, 20     RTS, DTR
  HSKi       2       <----   5         CTS
  TxD-       3        ---->  2         TD
  SG, RxD+   4, 8     ----   7         SG
  RxD-       5       <----   3         RD
  GPi        7       <----   8         DCD
  gnd        shield   ----   shield    gnd

Null modem cable
  [note:  some DTE devices may need RTS and DTR swapped on the DB-25 side.]

             Din-8           DB-25 (DTE)
  -----------------          ------------------
  HSKo       1        ---->   5        CTS
  HSKi       2       <----    4        RTS
  TxD-       3        ---->   3        RD
  SG, RxD+   4, 8     ----    7        SG
  RxD-       5       <----    2        TD
  GPi        7       <---[   20, 8, 6  DTR, DCD, DSR (DTR holds DCD&DSR high)
  gnd        shield   ----   shield    gnd

The classic "Mac to ImageWriter I" cable

             Din-8           DB-25 (DTE)
  -----------------          ------------------
  HSKo       1        ---->   8, 6     DCD, DSR
  HSKi       2       <----   20        DTR
  TxD-       3        ---->   3        RD
  SG, RxD+   4, 8     ----    7        SG
  RxD-       5       <----    2        TD
  GPi        7       <----   14        (paper out or other fault)
  gnd        shield   ----   shield    gnd

Part 3:  Signals

What do these things stand for?

  SG      signal ground
  gnd     safety ground

  HSKo    handshake out
  HSKi    handshake in
  TxD     transmit data
  RxD     receive data
  GPi     general purpose input

  TD      transmit data
  RD      receive data
  RTS     request to send
  CTS     clear to send
  DSR     data set ready
  DCD     data carrier detect
  DTR     data terminal ready
  RI      ring indicator
  SQ      signal quality detect
  (S)TD   sec. transmit data
  (S)RD   sec. receive data
  (S)DCD  sec. data carrier detect
  (S)CTS  sec. clear to send
  (S)RTS  sec. request to send
  RC      receiver clock
  TC      transmitter clock
  (TC)    ext. transmitter clock

  NS      new sync                    (Bell 208A)
  DCT     divided clock, transmitter  (Bell 208A)
  QM      equalizer mode              (Bell 208A)
  DCR     divided clock, receiver     (Bell 208A)

Part 4:  Unuseful Cables

Note:  This is for my own reference.  Nobody but me should care about these.

Beige cable with "BusinessLand" in red letters.
  RxD+ is not tied to SG but is left floating, so the signals may be
  weak for CS-232.  Also, while HSKi is tied to CTS, RTS is left floating,
  so this cable is "download only".

             Din-8           DB-25 (DCE)
  -----------------          ------------------
  HSKo       1        ---->  20        DTR
  HSKi       2       <----    5        CTS
  TxD-       3        ---->   2        TD
  SG         4        ----    7        SG
  RxD-       5       <----    3        RD
  gnd        shield   ----   shield    gnd

Grey cable, unmarked, with round (not squared) DIN-8 connector.
  The signal ground is tied to the safety ground--odd, but probably ok
  in practice.  HSKi is tied to both CTS and DCD--it seems to me that
  the mac won't be able to see either CTS or DCD drop because the other
  will still be high.

             Din-8           DB-25 [DCE]
  -----------------          ------------------
  HSKo       1        ---->  20        DTR
  HSKi       2       <----    5, 8     CTS, DCD
  TxD-       3        ---->   2        TD
  SG, RxD+   4, 8     ----    1, 7     gnd, SG
  RxD-       5       <----    3        RD
  gnd        shield   ----   shield    gnd

From the American bargain bin
  HSKo is not connected.  The signal ground is tied to the safety ground.

             Din-8           DB-25 [DTE]
  -----------------          ------------------
  HSKo       1        ---->            nc
  HSKi       2       <----   20        DTR
  TxD-       3        ---->   3        RD
  SG, RxD+   4, 8     ----    1, 7     gnd, SG
  RxD-       5       <----    2        TD
  gnd        shield   ----   shield    gnd


more third-party mini-DisplayPort adapters

miniDP-to-DP cable from Circuit Assembly Corp.Monoprice started selling mini-DisplayPort adapters a few months ago, but now another vendor has joined the game. Circuit Assembly Corp. sells not only the three types of adapters that Monoprice does (albeit at slightly higher prices) but also two it doesn’t.

  • The miniDP(female)-to-DP cable allows owners of laptops/desktops with full-size DisplayPort ports to connect to those crazy miniDP-only displays Apple (and others) sell.

Kudos to Circuit Assembly Corp. for finally providing interoperability between DisplayPort and mini-DisplayPort that had long been expected.

Apple finally updates Mac Mini

back of 2009 MacMiniFor those who have been waiting for a less antiquated MacMini (as I have been for well over a year now) the wait is now over. Apple released new Mini models this morning. The processors are about the same as before—no complaints there—but other components have moved from four-year-old technology to parity with the modern MacBook.

  • Nvidia GeForce 9400M graphics (from Intel GMA 950)
  • mini-DVI and mini-DisplayPort with dual-display support (from one full-size DVI port)
  • 4GB RAM ceiling, or perhaps higher when larger-capacity DDR3 DIMMs appear
  • draft 802.11n wireless networking (from 802.11g)
  • FireWire 800 (from FireWire 400) — adapters are available
  • five USB 2.0 ports (from four)
  • the US$600 model can write DVDs (from the US$800 model only) — now SATA
  • Bluetooth 2.1 (from 2.0) — a very minor change
  • 1066 MHz front-side bus (from 667 MHz)
  • the Apple Remote is still supported but no longer included

A miniDVI-to-DVI adapter is included in the box. To connect to an older VGA monitor will require either a miniDVI-to-VGA adapter or a miniDP-to-VGA adapter. (Theoretically Apple could have supported chaining a DVI-to-VGA adapter on the end of the included miniDVI-to-DVI adapter on the Mini, but I presume not. It doesn’t work on other miniDVI-equipped macs.)

All in all it looks pretty good. If you’re in the market for a nice, simple, silent, desktop Mac I recommend you buy one.

As before, the Mini comes with neither keyboard nor mouse. If you plan to buy a keyboard, Apple introduced a smaller wired keyboard today. It’s sort of a combination of the existing slimline wired keyboard (which has a numeric keypad) and the existing Bluetooth wireless one (which doesn’t). All three are new since I last discussed keyboards for Mac Mini two years ago.

In addition to the Mini, Apple updated the iMac, the MacPro, Airport Extreme, and Time Capsule today as well. I am surprised there aren’t new external displays also.

Whither Mac Mini?

Apple has been manufacturing the Intel-powered MacMini for three years now. All this time it has been using the Intel GMA 950 integrated graphics processor. The GMA 950 was considered underpowered even in 2006*, but by today’s standards it is seriously lacking. Compare to the MacBook’s graphic chip, which has been upgraded twice:

  • May 2006 MacBook: Intel GMA 950
  • November 2007 MacBook: Intel GMA X3100
  • October 2008 MacBook: Nvidia GeForce 9400M

In many ways the MacMini is an ideal machine. It’s inexpensive (for a mac) and blissfully quiet. I used to enthusiastically recommend them to fiends and family. I can’t recommend them now. Why pay $800 (or $600 without a DVD writer) for a MacMini with four-year-old integrated graphics when $1000 buys a white MacBook and $1200 buys a 20″ iMac?

The MacBook has much more capable graphics than the Mini. Also a keyboard, pointing device, integrated display, and battery are included. Even for those that plan to use their own keyboard, mouse, and display it probably makes sense to buy a white MacBook (and just leave the lid closed) than to buy a MacMini for $200 less.

The next version of OSX (Mac OS X.6 “Snow Leopard”) is due this spring. There are indications that Apple considers GeForce 9400M graphics to be essentially the minimum requirement to run Snow Leopard properly. These are unsubstantiated, but Snow Leopard includes OpenCL technology which is designed to make the power trapped in the machine’s graphics cores available for non-graphical tasks. It remains to be seen how heavily OpenCL will be utilized in Snow Leoard, but the Mini is now the only Mac sold with anything less than GeForce 9400M graphics.

Because the Mini has such antiquated graphics, there have been many upgrade rumors. None of them have panned out so far. The most recent one is from December: an OSX kernal extension file refers to a new MacMini with an Nvidia MCP79 chipset, which would indicate GeForce 9400M graphics. So some Apple watchers are predicting new MacMinis any week now, but they don’t know for sure. I guess we’ll see.

*Way back in May 2005 ExtremeTech wrote:

We can state flatly that if you buy a system using Intel’s GMA950 integrated graphics and want to play 3D games, invest at least $60 in an add-on card. If what you want is simply a system that can run standard office software, plus maybe play some DVD movies, then Intel’s new graphics core is probably suitable.

You might wonder what the point is of putting all the engineering effort into the 3D core, if it sucks so badly at games?

third-party mini-DisplayPort adapters available next week

miniDP-to-DVI and miniDP-to-VGA adapters from MonopriceRespected discount cable house Monoprice has added miniDisplayPort-to-DVI and miniDisplayPort-to-VGA adapters to its catalog with an ETA of January 16, 2009.

Third-party adapters were expected after Apple licensed the mini-DisplayPort spec, but it’s nice to see them actually arrive. Monoprice’s prices are about half of Apple’s, which is also welcome.

I was also expecting to see miniDisplayPort-to-DisplayPort and miniDisplayPort-to-HDMI adapters, and also actual miniDP cables (as opposed to short adapters), but none have appeared yet. Perhaps they are on their way.

[update: The catalog now also lists a miniDisplayPort-to-HDMI adapter.]

Mini-DisplayPort, a month later

Molex Mini-DisplayPortIt’s been more than a month since Apple introduced the Mini-DisplayPort connector on its new line of laptops. Here are some thoughts.

  1. I had presumed that Mini-DisplayPort was signal compatible with standard DisplayPort, with the same 20 pins (but in a different order), but there was no corroboration. Well, my unnamed source (how mysterious!) confirms that this is the case.

    [update: Shortly after I published this entry, further validation came in the form of a mini-DisplayPort licensing page on Apple’s web site. It supplies a PDF download for mini-DisplayPort connector dimensions and pinouts.]

  2. I mentioned that Apple was continuing to sell its 23″ Cinema Display (with DVI) an addition to its new mini-DisplayPort-only 24″ Cinema Display. However Apple has since discontinued the 23″ model, leaving it without a mid-range display that can be connected to any existing Apple desktop machine. This indicates to me that Apple soon plans to release new versions of the MacPro, iMac, and MacMini that will have Mini-DisplayPort ports. (It still sells 20″ and 30″ displays that support DVI, but for how much longer?)

  3. I thought we’d see third-party miniDisplayPort-to-DisplayPort adapters by now, but I have yet to find one. My unamed source says that Apple has contributed the mini-DisplayPort connector specification to VESA for possible inclusion in version 1.2 of the DisplayPort standard. If so, cheap third-party mini-DP adapters should be around the corner. (Component manufacturing giant Molex has apparently been working on making the connectors available.) This would allow Macs with mini-DisplayPort to drive standard DisplayPort monitors, and laptops and video cards with standard DisplayPort to drive Apple’s LED-backlit Cinema Displays.

  4. It may be possible to create an unwieldy miniDP-to-DP adapter today:

    The idea is to convey the native DisplayPort signals (not DVI signals) through the conductors of the DVI cable. This presumes that the two adapters have compatible pinouts and that they have enough conductors. (The pinout of that DisplayPort-to-DVI adapter shows 17 conductors, omitting only pins 13/14/16. DisplayPort cables are supposed to leave out 13 and 14, but not 16. It might be ok to leave out 16, though, since it would only be used by the auxiliary channel.) A bigger presumption is that the F/F DisplayPort coupler doesn’t cross conductors 1-12, which unfortunately it would have to do if it’s intended to allow two coupled standard DisplayPort cables to behave like a longer standard cable. My guess is that this crazy adapter wouldn’t work, but if anyone actually tries it please let me know the result.

  5. Apple’s $100 Mini DisplayPort to Dual-Link DVI Adapter has been delayed until late December. I guess they are having trouble with it.

  6. Many have run into DRM problems viewing media through the mini-DisplayPort connector—even standard-definition stuff that shouldn’t be affected by HDCP. This is yet another case of Digital Rights Management causing problems for legitimate users. It’s getting old. Supposedly, a QuickTime 7.5.7 update addresses the issue.

More on Apple’s new laptops, LED Cinema Dispay, mini-DisplayPort

mini-DispayPort (unplugged) and USB (plugged)I saw Apple’s new laptops in person today. I was able to take some pictures of the new mini-DisplayPort connector with my cell phone’s lousy camera. They are blurry, but I think you can get a sense for the size of the connector.

Unlike full-size DisplayPort connectors, they do not latch. In this regard, it seems that mini-DisplayPort is no better than mini-DVI and micro-DVI, which is too bad.

I also got to see the new 24″ LED Cinema Display. (In this case LED refers to the backlighting. It’s still an LCD panel, not something exotic like OLED.) It connects to the laptop via a cable with three connectors: mini-DisplayPort for graphics, USB for the iSight camera and the integrated three-port USB hub, and  MagSafe power connector. The power connector is to provide power to the laptop, not to provide power to the display. Power to the display comes from a separate cable that plugs into a standard outlet, though it is confusingly omitted from almost all of Apple’s product imagespower, ethernet, USB, mini-DisplayPort.

I wonder what it would take to connect the 24″ LED Cinema Display to a PC laptop or video card with DisplayPort. A DisplayPort-to-miniDisplayPort adapter would be needed, of course, though none exist yet. Except for that, I would hope that it would work fine with the MagSafe and USB connectors left unconnected. (I have an Apple DVI 15″ LCD Studio Display connected to a standard PC and it actually requires the USB connection, so it wouldn’t be too surprising if the LED Cinema Display did also. The 1999-era Studio Display doesn’t send any data over USB, but it seems to use USB to detect computer power-on and power-off.)

Many have asked how to connect a new LED Cinema Display to an older Mac. The answer, at least for now, is that it can’t be done. There are adapters to connect newer Mac laptops to older displays, but not the other way around. Apple says all their laptops and desktops will eventually support mini-DisplayPort but, until then, the only machines that can drive LED Cinema Displays are the new Mac laptops announced last week. That’s why Apple continues to sell the existing 23″ Cinema Display with DVI. Some day someone like Gefen may sell a DVI-to-DisplayPort converter, but it will be a niche product and it will not be cheap. (On the other hand, I expect both DisplayPort-to-miniDisplayPort and miniDisplayPort-to-DisplayPort adapters will soon become commonplace.)

As for the laptops themselves, I gave the new buttonless trackpads a test-drive and I think I could get used to them. Depressing the entire trackpad to click felt a bit unnatural, but just a bit. Three-finger swipes left and right across the trackpad in Safari for page-back and page-forward did feel natural.

Much has been made about dropping FireWire (IEEE 1394) from the MacBook. The MacBookAir never had FireWire, presumably for size reasons. The new MacBookPro no longer has a FireWire400 port but does have FireWire800, so FireWire400 devices can still be used after buying a new cable or a small adapter.  The new MacBook, though, has neither FireWire400 nor FireWire800 and I wonder why. Is it because the new NVIDIA chipset doesn’t support FireWire as competently as the previous version’s Intel chipset? Could it be to further differentiate the MacBookPro from the MacBook now that the MacBook has more of the Pro’s features (for example, the backlit keyboard on the high-end model)?

I’m not in the market for a new laptop but if I were I would have to weigh the lack of FireWire before buying a MacBook, which is otherwise a very nice machine. I have only a couple of FireWire peripherals (the only one that gets much use is an ancient 3rd-generation iPod) but no FireWire also means no Target Disk Mode and one way fewer to recover data when things go wrong.

What I’m really hoping for is a MacMini updated with most of the new MacBook’s internals. I’d buy one even if it lacked FireWire. The current MacMini is appealing and whisper-quiet, but it’s a generation behind even the older MacBook. It could really use the increased graphics power and higher RAM ceiling (and presumably also mini-DisplayPort) that would come with an update.

Apple’s new laptops employ Mini-DisplayPort

standard USB port next to Mini-DisplayPort

Until today, Apple’s three laptop lines used different display connectors. The MacBook used mini-DVI, the MacBook Air used micro-DVI, and the MacBook Pro used vanilla DVI. I thought Apple might standardize on a single display connector, perhaps micro-DVI.

I was partially correct. Today’s updated versions of the MacBook, MacBook Air, and MacBook Pro do all use the same display connector, but it’s mini-DisplayPort, not micro-DVI.

Apple needed another laptop display connector like a moose needs a hat rack, but mini-DisplayPort does have some advantages. For one, the connector is small—about 60% the size of a standard USB-A connector. (See comparison image, above.) It has a 1 Mbps bi-directional (half-duplex) auxiliary channel that could be used to handle webcam or other peripheral data. It can also drive resolutions above 1920×1200, which dual-link DVI can handle but single-link DVI variants can not. Perhaps the connector will mate with the socket more securely than mini-DVI does, but this is yet to be determined. (Latching is a feature of standard DisplayPort connectors, but so far as I can tell Apple created mini-DisplayPort on its own. It is unclear if mini-DisplayPort connectors latch. [update: They don’t.])

The downside? Mini-DisplayPort is presumably signal-compatible with standard DisplayPort, which “is the future” but hasn’t really caught on yet. This will likely be a win in the long term, but it’s not signal-compatible with DVI or HMDI (nor VGA, for that matter). DisplayPort implementations are permitted to pass DVI-compatible signals through the connector, and presumably this is what Apple has done, at least for single-link DVI.

Apple’s $29 Mini DisplayPort to DVI Adapter supports single-link DVI. To exceed 1920×1200 requires the Mini DisplayPort to Dual-Link DVI Adapter, priced at a whopping $99. Presumably the dual-link adapter has circuitry that actually converts the DisplayPort signals, which is why it requires USB power. (There is also a $29 Mini DisplayPort to VGA Adapter.)

ANSI vs. ISO keyboards

ISO (top) and ANSI (bottom) keyboardsNorth America mostly uses ANSI keyboards. Europe mostly uses ISO keyboards. The layouts are similar, but ISO has a few extra keys. An ANSI keyboard usually has two keys between L and Return, while ISO usually has three. Also, ANSI places Z adjacent to the left Shift key, but ISO has an intervening key. To allow for this, ANSI has a wider left Shift key than ISO.

I own a couple of ISO keyboards. I bought them on eBay in early 2006 because they were the cheapest USB keyboards I could find at the time. I can’t really type on them, though, because my left pinky consistently hits the intervening key when it is hunting for the Shift key. (My right pinky also has some trouble with Return, but not to the same extent.)

The image to the right shows an ISO keyboard on top and an ANSI keyboard on the bottom. The ISO model is a Silicon Graphics SK-2502U. The ANSI model is an Inland “Windows 107-Key USB Keyboard” (which, at $4.99, just may be the cheapest keyboard for Mac Mini). Note the width of the left Shift keys and the relative location of the Z keys.

Now take a look at the European Dell Vostro 1310 keyboard shown below. Dell has inadvertently created a hybrid ANSI/ISO layout. This is no good because they have shifted all the letters on the bottom row one slot rightward from where a touch-typist would expect them to be!

Dell Vostro 1310 keyboardThe Z should be below A and S (in both ANSI and ISO) but on this laptop the Z is below S and D. Oops.

Dell admits its blunder and will provide replacement keyboards.

The Vostro keyboard error has received a lot of press on the web, but to my knowledge noone has mentioned the ANSI vs. ISO issue. It would seem to explain how this astounding error could have been made when the North American Vostro keyboard was adapted for European release.