- Why can't an old motorola mac emulator run on a modern system mac os#
- Why can't an old motorola mac emulator run on a modern system update#
- Why can't an old motorola mac emulator run on a modern system full#
- Why can't an old motorola mac emulator run on a modern system software#
- Why can't an old motorola mac emulator run on a modern system code#
Why can't an old motorola mac emulator run on a modern system full#
Full 32bitness was reserved for the upcoming IIci and IIsi. What Apple deliberately chose NOT to do with those upgrades was give the II and SE full 32bit ROM code.
Why can't an old motorola mac emulator run on a modern system update#
Apple released a ROM update and a SWIM chip (Super Woz Integrated Machine) to replace the IWM chip (Integrated Woz Machine) which added 1.44M support and fixed the RAM capacity bug.Īpple also released a ROM and SWIM kit for the SE, which converted them into the same as an SE/FDHD.
The Mac II was initially released without support for 1.44M floppy drives and it had bugs that prevented large SIMMs from being used in Bank A. If there was an AMU then (IIRC) no virtual memory option appeared in the Memory control panel, or it was greyed out. The AMU was essentially a dummy chip and the ROM checked for it or the MMU. The cheapest version of the Macintosh II (it and the LC were the only two Apple systems to use the 68020) had an “Apple Memory Unit” plugged in place of the “Memory Management Unit”. Posted in Ask Hackaday, Hackaday Columns, Slider Tagged 68040, 68k, 68LC040, BSD, desoldering, Powerbook, Powerbook 500 Post navigation The comments are open, and the eventual answer will assuredly be very interesting. The explanation to this problem is going to be very hard to find, which is why this project is an Ask Hackaday column. There might be a handful of wizened Apple engineers who know what the problem is. Surely there’s some errata tucked away in a datasheet somewhere that will tell us what’s going on. Without an obvious solution to this problem apparent in the software, hardware, or even the ROM for this laptop, this project has turned into a mystery. If it works with an FPU-less CPU, it should work with an FPU-equipped CPU. We can also trust the PCB that has been reworked several times over the course of this project. We can probably trust the NXP support rep. This is the second new CPU in this computer, and this time the CPU probably has a floating point unit. The problem probably isn’t software.Īccording to the Motorola, Freescale, and NXP documents, the problem probably isn’t hardware. Since tested the CPU under NetBSD, there’s probably nothing weird going on in the ROM, either Mac ROMs are dedicated almost entirely to the Macintosh Toolbox and the Mac OS.
Why can't an old motorola mac emulator run on a modern system mac os#
The FPU-equipped Powerbook 550 exists and the Mac OS uses the same Gestalt ID for the entire Powerbook 500 series. The CPU reports no FPU in both Mac OS and NetBSD.
Why can't an old motorola mac emulator run on a modern system software#
The first step to diagnosing a problem is eliminating possible problems, and in this case it’s probably not a software issue. It isn’t, and there is no satisfactory explanation for why that’s the case.
Why can't an old motorola mac emulator run on a modern system code#
They’re both pin compatible with each other, object code compatible (except for FPU instructions), and timing requirements are the same. The holy scroll passed from Motorola to Freescale to NXP states just a few differences between the FPU-less 68LC040 and the FPU-equipped 68040. Thus, Ask Hackaday: why doesn’t this FPU work? This is weird, shouldn’t happen, and now is at the limits of knowledge concerning the Powerbook 500 architecture. Assured by an NXP support rep this CPU did in fact have a floating point unit, checked the Mac’s System Information. The new chip is a Freescale MC68040FE33A. He could put the Powerbook back in the parts bin, or he could source a 68040 CPU with an FPU. Still, it’s an impressive display of rework ability, and generated a factlet for the marginalia of the history of consumer electronics.įaced with a laptop that was effectively unchanged after an immense amount of very, very fine soldering, had two choices. The replacement CPU was sourced from China, and even though the number lasered onto the new CPU read 68040 and not 68 LC040, this laptop was still without a floating point unit. He pulled the CPU card from the laptop, got out some ChipQuick, and reworked a 180-pin QFP package. A few months ago, was looking for a project and decided replacing the CPU would be a valuable learning experience. The ‘ LC‘ designation inside the part name says this CPU doesn’t have a floating point unit. The CPU inside these laptops - save for the high-end Japan-only Powerbook 550c - was the 68LC040. This was one of the first laptops that looked like a modern laptop. They had built-in Ethernet, a trackpad instead of a trackball, stereo sound, and a full-size keyboard. Released in 1994, Apple’s Powerbook 500 series of laptop computers were the top of the line. This is a tale of old CPUs, intensive SMD rework, and things that should work but don’t.
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