Subject: Re: ROM 1 vs ROM 3???
From: Rubywand <rubywand@swbell.net>
Date: Mon, Sep 28, 1998 03Ø45Ø Ð
Message-id: <360F68BA.47E6071D@swbell.net>

Mitchell Spector wrote:
> 
> In article jgreer4350@aol.com (JGreer4350) writes...
> 
> >I don't understand the difference between the two. Is one better or more
> >compatible?
> 
>     Well to an outsider (anyone totally unfamiliar with the Apple II)
> the differences are rather insignificant and trivial. For the most
> part, it could be summed up as the same original Apple IIgs computer,
> only with more built-in RAM and ROM. That observation wouldn't be too
> far off the mark, as the Apple IIgs--as manufactured and shipped from
> Apple--remained relatively unchanged throughout its 6+ year lifespan.
> 
>     As for a detailed explaination of the differences, here they are
> in a nutshell: The first motherboard revision of the Apple IIgs had
> 256K built-in, 128K of ROM. The original firmware that plugged into
> this board was known as the "ROM 00", which was then replaced by the
> "ROM 01" firmware (which Apple offered as a free update by simply
> swapping a single ROM chip).
> 
>     The next motherboard revision was called "The Apple IIgs with
> 1 Megabyte of RAM" and as the name implied, came with just over a
> 1 MB of memory built-in (1152K to be exact--both machine had 128K
> of 'Slow RAM', but the ROM 00/01 had 128K for 'Fast RAM' while the
> ROM 3 had 1024K. So 128K+128K=256K or 128K+1024K=1152K). It also
> had double the ROM size, totaling 256K (the ROM 00 and 01 firmware
> was only 128K) and as the third revision of the firmware, Apple
> decided to call it the "ROM 3" (rather than ROM 02). The new board
> also featured a newer ADB micro (built-in keyboard mouse, sticky
> keys, updating of extended keyboard LEDs), the MB0 signal required
> by video cards available in slots 1 through 6 (rather than just
> slot 3 on the old board), hardware shadowing of text page 2, a
> removable clock battery, a set of jumper pins to lock out the
> classic text Control Panel and decreased electrical noise and
> power consumption, so it had cleaner sound and more likely to
> work with sensitive cards.
> 
>     As for the firmware changes, they added many more toolsets in
> ROM and updated existing ones (System 5 versions), gave it faster
> 3.5 drive and RAM Disk firmware when used in 8-bit mode, made it
> so you could set slot-4 to 'Your Card' without losing the mouse in
> GS/OS and made it so AppleTalk less was constricted in terms of slot
> assignment. They cleaned up the Classic text Control Panel, let you
> warm-boot to resize RAM Disks, added new System Monitor features,
> and of course, many bug fixes (and new bugs added). :)
> 
>     In summary, the ROM 3 board was slightly faster (maybe 5-10%)
> when running native software and gave you many small benefits you
> did not get with the ROM 00/01 board (being able to have 5 MB of
> DMA memory was an obvious one, not having that annoying buzzing
> and hissing from the Ensoniq chip or using a 15 MHz Zip GS were
> a couple more worth mentioning). Originally there were compatibility
> issues with older software titles, just like when the ROM 01 was
> released, but anything worthwhile has been updated or patched
> by now. It was mostly hardcoded games and demos that had problems
> with the new ROM. All this is off the top of my head, so I may
> have missed a couple of things, but that should give you a good
> idea.
> 
> Mitchell Spector
> spec@vax2.concordia.ca


     Here's a list you posted several weeks ago which may help ...

>>

     The ROM 3 Apple IIgs offers many minor enhancements vs. the ROM-01
which make the machine more functional and pleasant to use:

- You get a machine that is about 5-10% faster for GUI, floppy disk
  loading and RAM Disk operations (due to updated smartport firmware
  and System 5 tools being in ROM).

- A machine that is more flexible when working with AppleTalk and
  slots (you don't have to give up an extra slot and you can stick a
  card in slot 4 and still use the mouse in GS/OS).

- A nicer text Control Panel that lets you resize RAM Disk with a
  warm-boot and a cleaner way to size it too (no min/max size junk).
  Also a 'Mouse' menu and other existing things cleaned up and made
  better.

- A just over 1 megabyte of RAM built-in to start off with; so, you
  can have 5 MB of DMA compatible memory in total.

- The MB0 signal provided in slots 1 through 6, so you can stick
  in a Video Overlay Card _and_ Second Sight in together, and not
  worry about having to reserve slot 3.

- Hardware shadowing of text page 2 with Alternative Display Mode
 (no slowing down your system to a crawl when you see a screen full
  of 2's running 8-bit software).

- A newer ADB keyboard microcontroller with built-in sticky keys,
  keyboard mouse and compatibility with the indicator LEDs
  on extended keyboards.

- A removable Lithum battery (in a snap case. Just pop the old one
  out when your clock and Control Panel settings stop working).

- Less power consumption and electrical noise from the motherboard,

- A set of pins (location 'S1') on the motherboard to make the text
  Control Panel disappear, making your GS settings tamper proof where
  young children are around


    There are even a couple of more goodies, like the Step/Trace
commands in Monitor or the improved disassembler. Even if you are not a
programmer, they're handy for peeking at SHR graphics still in memory
(from Monitor hit 'S' and then the return key).

    Things like sticky keys and mouse keyboard come in handy too-- like
if you are eating or drinking with one hand, you can still reset the
computer using the other.

    The down side is that some old GS games and demos won't run. However
many of the more worthwhile ones have been patched.

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Rubywand