MODE32/System compatability

Markintosh

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Mar 31, 2023
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Hi gang, I am upgrading the RAM in my SE/30 to 128MB. I believe I have the factory ROM chip installed. I understand I'll need MODE32 for the Mac to recognize memory over 8MB. What Systems is MODE32 compatible with? Can System 6.0.3-.8 run with it installed, or is Sys 7.x required?

For that matter, is System 6 supported with any of the popular 3rd party ROM's?

Thanks in advance
 

Nixontheknight

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Nov 3, 2021
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Hi gang, I am upgrading the RAM in my SE/30 to 128MB. I believe I have the factory ROM chip installed. I understand I'll need MODE32 for the Mac to recognize memory over 8MB. What Systems is MODE32 compatible with? Can System 6.0.3-.8 run with it installed, or is Sys 7.x required?

For that matter, is System 6 supported with any of the popular 3rd party ROM's?

Thanks in advance
I'm pretty sure MODE32 can only be run on system 7.1 and never, as older versions don't have support for 32-bit addressing, afaik
 

retr01

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Only Apple's 32-bit enable runs on System 7.1 while Connectix's MODE32 should work with System 7 through 7.5.5. :)
 
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retr01

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Yeah, my bad. System 6 did not feature 32-bit memory addressing. Then, System 7.0 and up provided 32-bit addressing option.

Connectix did have a product called Optima that can provide 32-bit addressing for System 6.


Remember, if a program isn't written for 32-bit addressing, then update or turn off 32-bit addressing. That includes CDEVs, INITs, etc.
 
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Crutch

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I’ve never used 32 bit addressing under System 6 and certainly didn’t know it was possible. That said, this Optima product looks interesting but it says “not compatible with MultiFinder” so … it lets you run just one giant application at a time using your more-than-8MB RAM? Sounds …. not very useful.
 

retr01

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This is what I gathered from the Optima 32 v2.0 page on Macintosh Repository:
  • OPTIMA 2.0.0 can run on any Mac II class machine, regardless if it was manufactured with "32-bit clean" ROMs.
  • OPTIMA normally requires System 6.0.7, and only functions as a RAM disk under System 7. On the IIci only, it can be made to work with Systems 6.0.4-6.0.7. Foreign Systems (including Kanji) can run with 6.0.6 and 6.0.7, but 6.0.7 is recommended.
  • When operating in 32-bit mode, ALL of the INITs, cdevs, and programs that you run must be 32-bit clean. Currently, MultiFinder is not 32-bit clean, and as a result, only operation from under Finder is available. NuBus cards which contain their own INITs in ROM must also have 32-bit clean versions.
  • If your machine hangs on booting, before you can get to the Control Panel to turn OPTIMA off, •••boot while holding down the ESCape key•••, or from a different system floppy. This will present a dialog box allowing you to switch back to 24-bit mode.
  • If you are using MAXIMA with OPTIMA, you must install MAXIMA first, restart, and only then turn OPTIMA on. Before you de-install or drag MAXIMA out of your System Folder, OPTIMA must be turned off, and then the machine restarted.
  • NUMEROUS programs and INITs are NOT 32-bit clean.
  • It is suggested you start from a minimum (absolutely essential) System set, and add INITs in small numbers. There are so many revs of so many INITs, that it is often faster to test the ones you have rather than checking an exhaustive compatibility list which may already be out of date.
I agree that Optima seems not useful. Safer to do 32-bit stuff under System 7.
 
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Markintosh

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Mar 31, 2023
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Wow-thanks everyone for your input! I think I'll keep my SE w/4MB on System 6.0.x & run the SE/30 w/128MB on Sys 7.1 with one of the MODE32 flavors.

Thanks again for the info!
 
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Patrick

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I wonder if the real value add for Optima was the ability to have a massive RAM disk.
So yes, you can only run one big Application at a time. (like photoshop) but you could run it from a big RAM disk.

..

just a guess though.
 
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speakers

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A footnote to this: System 7.5.3 and 7.5.5 have MODE32 builtin. No need to install anything .. just enable 32-bit addressing in the Memory control panel and your dirty old SE/30 will happily see more than 8MB.

I use 7.5.5 on my SE/30 with 16MB (4*4MB in bank A).
 
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retr01

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just enable 32-bit addressing in the Memory control panel and your dirty old SE/30 will happily see more than 8MB.

I updated to 7.5.5 on my SE/30 but do not see 32-bit addressing in the Memory control panel. Can you clarify?

1681951832672.jpeg
 

retr01

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A footnote to this: System 7.5.3 and 7.5.5 have MODE32 builtin. No need to install anything .. just enable 32-bit addressing in the Memory control panel and your dirty old SE/30 will happily see more than 8MB.

@Nixontheknight, this is what @speakers is attesting to. I am trying to clarify. Connectix MODE32 for System 7 is normally put in the extensions folder. I wonder if 7.5.3 and 7.5.5 have that built-in?
 
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Crutch

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I think @speakers is mistaken. I don’t believe MODE32 is built into 7.5.3 or 7.5.5.

To my knowledge, all flavors of System 7 that don’t require 32-bit clean ROMs (i.e. 7.6 and higher … in which case MODE32 is useless) need MODE32.
 
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retr01

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Yeah. That was what I thought. Apple didn't build in MODE32. They only offered MODE32 as an add-on INIT for Sytstem 7.1, and then Connectix agreed with Apple to provide it.
 
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retr01

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I found a document by Connectix that "MODE32 is provided free of charge courtesy of Apple Computer through a special distribution agreement with Connectix Corporation."

Reading further in that document about MODE32, Connectix cautions:

It will enable Macintosh II, IIx, IIcx, and SE/30 computers to use standard System 7 32-bit addressing. It is not functional on other types of computers.

Some applications and INITs are not "32-bit clean". That is, they are incompatible with 32-bit mode. Such software will usually cause your system to crash immediately when run in 32-bit mode. When you need to work with any non-32-bit clean INITs or applications, we recommend using MAXIMA. MAXIMA extends the addressing of your physical memory to 14 megabytes without resorting to 32-bit addressing, so it is compatible with all applications.
Please remember that when running in 32-bit mode, all of the INITs, devs, and application software you use must be 32-bit clean.

So, the Macintosh II, IIx, IIcx, and SE/30 computers with 32-bit addressing enabled using MODE32 may crash if a 24-bit program is accessed.

Some articles from TidBits provide historical insight about customers' whole 24-bit/32-bit furor and Apple's lack of solving the problems that Connectix helped to solve. IMHO, bandaids. :)

Using modern ROM SIMMs seems to be more appropriate and manageable.
 
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retr01

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Yep, my mistake. MODE32 must be installed on 7.5.3/7.5.5.

When Apple licensed it from Connectix in 1994, they announced that a future release of MacOS would have it built-in. Never happened.

Yeah, MODE32 7.5 version should be installed for System 7.5 through 7.5.5, not the earlier version of MODE32.