Coding for the 512K (possibly 128?) with Symantec

[Mu0n]

I usually go as low as using the Mac Plus as a target, using:
-Symantec C++ 6.0
-Using MacTraps and/or ANSI
-Default compiler settings, at least 384K of partition memory for the app

However, that starts to fail if I try launching those programs with a 512K emulated in Snow, Finder 4.1, using its 64k ROM file. I get a mac bomb ID=02.

I've tried:

-using the "Old MacTraps" library instead of "Mac Traps"
-lowering the partition memory used to 256K
-forcing the compiler settings to use 1-byte alignment for structs

None of those move the needle.
Do you absolutely have to use something like THINK C 3 or 4 to get there?

edit - Finder 4.1 under a Plus is able to launch my program, so it's not a Finder/System issue.

 

[Snial]

I usually go as low as using the Mac Plus as a target, using:
-Symantec C++ 6.0
-Using MacTraps and/or ANSI
-Default compiler settings, at least 384K of partition memory for the app

However, that starts to fail if I try launching those programs with a 512K emulated in Snow, Finder 4.1, using its 64k ROM file. I get a mac bomb ID=02.

I've tried:

-using the "Old MacTraps" library instead of "Mac Traps"
-lowering the partition memory used to 256K
-forcing the compiler settings to use 1-byte alignment for structs

None of those move the needle.
Do you absolutely have to use something like THINK C 3 or 4 to get there?

edit - Finder 4.1 under a Plus is able to launch my program, so it's not a Finder/System issue.

I bring you: MacBaby! A full-speed (0.7KIPs) Manchester Baby emulator (the world’s first stored program computer).

It’s written in THINK C 5 and runs on a Mac 128kB and 512kB Mac down to System 1.

At least one of the downloads should include the source code!

https://68kmla.org/bb/threads/macbaby-an-emulator-for-the-worlds-first-von-neumann-computer.49556/

 

[Mu0n]

That's a really cool project.

edit - I got THINK C going, but simply creating a THINK C 5 project with:

-MacTraps
-384K partition size
-adding the main .c source file, crossing my fingers it includes the tree of source file I made in the same directory as my Symantec C++ 6.0 project

It builds!
But it crashes under my dev environment (bus error) and crashes under Snow w/512K, still ID=02

 

[thecloud]

I also used THINK C 5 (or earlier) for my stuff that ran on early Macs. The ID=2 error is an address error, which means something is accessing a nil or odd memory address. The first thing I would look for is whether anything in your code calls a Toolbox function which is in the 128K ROM but not in the 64K ROM. That means you have to limit yourself to what's documented in Inside Macintosh I-III. Inside Macintosh IV is new 128K ROM material, while Inside Macintosh V has 256K ROM and 68020-related stuff.