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Exploring the Macintosh ROM (2019)

macgui.com

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Re: Exploring the Macintosh ROM (2019)

#21

Post by msgilligan »

cy384 wrote: post #14

if you want to mess with Mac ROMs now, I think Ghidra is a nicer experience than most of the vintage tools, and you can use QEMU with GDB (at least for the Q800 ROM).

I used MacNosy extensively in the Mac 68k era. Though I haven’t used Ghidra, reading about it reminded me of the fun (and frustration) I had with MacNosy.

I have no doubt Ghidra has a superior overall user interface. But, as memory serves, Nosy had many features specifically for the classic MacOS and ROM that I assume Ghidra lacks.

Re: Exploring the Macintosh ROM (2019)

#22

Post by dirtyhippiefree »

0xDEADFED5 wrote: post #3
ivolimmen wrote: post #2

I do not know if I am the only one but I can not connect to the site. The DNS resolves but I get the feeling this is "their way" of dealing GDPR? That or it actively blocks me because I have Linux in my user-agent? It's fishy.

I can't connect either, probably the HN Embrace of Doom? https://web.archive.org/web/20231106024332/https://macgui.co...

Doing a Google Advanced Search for the exact phrase “HN Embrace of Doom” shows •one• link…this post…

Show HN a Googlewhack: Success

Productive use of a term Google can’t find: Thought experiment but nothing else

Re: Exploring the Macintosh ROM (2019)

#23

Post by speed_spread »

rjsw wrote: post #18
vardump wrote: post #17

Earlier quoted context omitted.

Mac OS and Atari ST had both Motorola 680x0 CPUs. So both had a flat address space.

Only one of them ran an operating system that exposed it to applications.

Motorola 68000 CPU had no MMU so OS and applications ran in the same address space so anyone could do anything and a lose pointer could crash the whole box at anytime. This is true for all early Mac, Amiga and Atari. 68020 CPU was the same. There was an MMU only from the 68030 but still many OS didn't take advantage of it upon release.

Re: Exploring the Macintosh ROM (2019)

#24

Post by rjsw »

speed_spread wrote: post #23
rjsw wrote: post #18

Earlier quoted context omitted.

Only one of them ran an operating system that exposed it to applications.

Motorola 68000 CPU had no MMU so OS and applications ran in the same address space so anyone could do anything and a lose pointer could crash the whole box at anytime. This is true for all early Mac, Amiga and Atari. 68020 CPU was the same. There was an MMU only from the 68030 but still many OS didn't take advantage of it upon release.

Mac OS put code into segments that could be moved around, Atari ST TOS didn't do this.

Re: Exploring the Macintosh ROM (2019)

#25

Post by swagempire »

dirtyhippiefree wrote: post #22
0xDEADFED5 wrote: post #3

Earlier quoted context omitted.

I can't connect either, probably the HN Embrace of Doom? https://web.archive.org/web/20231106024332/https://macgui.co...

Doing a Google Advanced Search for the exact phrase “HN Embrace of Doom” shows •one• link…this post… Show HN a Googlewhack: Success Productive use of a term Google can’t find: Thought experiment but nothing else

Please me more expansive in your mind and support starting new trends...

Re: Exploring the Macintosh ROM (2019)

#26

Post by snvzz »

speed_spread wrote: post #23
rjsw wrote: post #18

Earlier quoted context omitted.

Only one of them ran an operating system that exposed it to applications.

Motorola 68000 CPU had no MMU so OS and applications ran in the same address space so anyone could do anything and a lose pointer could crash the whole box at anytime. This is true for all early Mac, Amiga and Atari. 68020 CPU was the same. There was an MMU only from the 68030 but still many OS didn't take advantage of it upon release.

68000 had no MMU and didn't support one, due to inability to recover from bus error.

68010 supported an MMU, so did 68020.

68030 bundled a MMU (except EC variants).

Re: Exploring the Macintosh ROM (2019)

#27

Post by snvzz »

TMWNN wrote: post #19
Someone wrote: post #15

Earlier quoted context omitted.

> The Amiga and Atari ST were home computers not workstations, their UI had to be usable on the crappy TV sets most households would have owned back then. It didn’t have to be; it was a design choice. It seems they found colour support and price more important than having a crisp display. As examples why it is a choice: - the TRS-80 (typically) came with its own monitor, for 64-character lines and ‘superior’ image qu…

> “In the home computer market, the PET line was soon outsold by machines that supported high-resolution color graphics and sound”) PET and TRS-80's graphics are inferior to Apple II in their inability to do anything other than character-set graphics. Apple II in 1977 offered not just color, but bitmapped graphics. Had IBM's MDA in 1981 offered Hercules-style bitmap graphics, it's possible that CGA might never have s…

>Had IBM's MDA in 1981 offered Hercules-style bitmap graphics, it's possible that CGA might never have seen widespread use at all.

It'd have an associated increase in cost. You'd need to add some SRAM, even for tiled graphics.

Re: Exploring the Macintosh ROM (2019)

#28

Post by TMWNN »

snvzz wrote: post #27
TMWNN wrote: post #19

Earlier quoted context omitted.

> “In the home computer market, the PET line was soon outsold by machines that supported high-resolution color graphics and sound”) PET and TRS-80's graphics are inferior to Apple II in their inability to do anything other than character-set graphics. Apple II in 1977 offered not just color, but bitmapped graphics. Had IBM's MDA in 1981 offered Hercules-style bitmap graphics, it's possible that CGA might never have s…

>Had IBM's MDA in 1981 offered Hercules-style bitmap graphics, it's possible that CGA might never have seen widespread use at all. It'd have an associated increase in cost. You'd need to add some SRAM, even for tiled graphics.

Oh, sure. But there's nothing exotic about Hercules (thus the endless clones of it) that prevented IBM from implementing something like it in 1981 except a) cost and b) possibly some vague worry that graphics/color = games = non-serious computer.

For 40 years people have said that IBM made a mistake by only implementing the garish CGA 4-color palette on RGB monitors. But given that that was also done for a) and probably b), this discussion has made me think that perhaps non-graphics MDA might have been as big a mistake for IBM, maybe even more so if it could have been implemented for less cost than proper full-palette CGA on RGB.

Re: Exploring the Macintosh ROM (2019)

#29

Post by nxobject »

kabdib wrote: post #11

When I was at Apple (started in '87, about the time the Macintosh II shipped), many of the groups in the systems software and support orgs (development tools, networking, etc.) had a table where there were binders of ROM assembly listings, maybe 2-3 linear feet of paper bound in a metal rack. They were a big help with particularly tricky crashes, or for figuring out ROM bugs, or just learning about the system. This p…

Managing a common large body of assembler like that, in hardcopy, seems to be a lost art... it reminds me of how the same amount of assembler needed to be managed in hardcopy for the Apollo DSKY/AGC, complete with paper changelogs, line number conventions, etc. [1] But a lot of the bookkeeping there looks like was needed as well to keep track of changes to punchcard decks.

[1] https://www.youtube.com/watch?v=-y37tXoBDx0

Re: Exploring the Macintosh ROM (2019)

#30

Post by snvzz »

TMWNN wrote: post #28
snvzz wrote: post #27

Earlier quoted context omitted.

>Had IBM's MDA in 1981 offered Hercules-style bitmap graphics, it's possible that CGA might never have seen widespread use at all. It'd have an associated increase in cost. You'd need to add some SRAM, even for tiled graphics.

Oh, sure. But there's nothing exotic about Hercules (thus the endless clones of it) that prevented IBM from implementing something like it in 1981 except a) cost and b) possibly some vague worry that graphics/color = games = non-serious computer. For 40 years people have said that IBM made a mistake by only implementing the garish CGA 4-color palette on RGB monitors. But given that that was also done for a) and proba…

Interesting; I was not aware CGA was also 1981.

With that in mind, it's indeed weird that they shipped MDA the way it was.

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