Hi Jeffrey,

If you’re the original buyer of the three Quadra 840AVs and never make any
hardware upgrade, you are able to know what computer you have reading the Apple
"sticker" in the back (or bottom) of the computer. (Quadra 800, Quadra 840 AV
and PowerMacintosh 8100 share the same box / design, the 'only' change is the
mother board [+ name in front, back])

Other idea, it could be the VRAM SIMM (Video Ram) connector.

Last idea: around 1991 / 1993, Apple have sold the introductory computer
sometimes with a ROM SIMM (YES, a ROM SIMM), and after some weeks (few days
after the computer introduction) the ROM appears as always / most of time,
soldered on the MLB. (Main Logic Board). I even saw (on prototypes) flash ROM
(Quadra 700/900 I think).

How can you know what is on your box ?

a. Check under the Apple Menu: Apple System Profiler (I think this is the name);
b. For VRAM: use the same monitor and check the possible values in the Monitor
Control Panel (# of colors)
c. Gestalt() and AppleScript (or the development tool you like) and ask for the
hardware informations (see InsideMacintosh on the Apple server).

Note: 2 MB is the amount of VRAM you need to if you want to have thousands of
colors with an Apple 21" Color Monitor.


A last one:

<http://developer.apple.com/techpubs/hardware/Developer_Notes/Macintosh_CPUs-68K_Desktop/>

You will find there a list of pdf Hardware Developer’s Notes; I usually find the
hardware information I need there.

Have a nice day,

Emile Schwarz
Mougins, France

>I have several (3) Quadra 840AVs. Today I noticed that one of them has
>a slot at J24 (I think) on the motherboard, next to the four SIMM
>slots. This slot is occupied by what appears to be a small RAM stick,
>which has printed on it "2MB SIMM APPLE COMPUTER". What is this, and
>why do the other two machines not have it? I'll add that this machine
>has a CDROM drive while the others do not, if that's significant. 

>Thanks,

>Jeffrey Ohlmann