Macintosh 128K: Technical Specifications | Hacker News Reader

Macintosh 128K: Technical Specifications

support.apple.com

29 pointsshawndumas26 comments

That's sort of impressive that MacOS supported the original mac up to MacOS\System 7 (released 1997 - a full 13 years later)

Not quite: it supported System 7.0.1P, which was released in March 1992 [1]. That's 8 years; still pretty impressive.

[1]: http://en.wikipedia.org/wiki/System_7#Version_history

Oh my mistake, I read the wrong version dates from that very wikipedia page. But yes you are correct, that is still pretty impressive

Also "support discontinued in 1998", more than 14 years after introduction and nearly 13 years after the product has been discontinued.

I think the original 128k Mac stopped getting OS (then simply called "System," no "Mac OS" until System 7.5) support at version 4.0 in 1987. So, three years, not ten.

The Mac Plus (released in January 1986) did have support in System 7 up to 7.5 in 1996.

The 128k Mac was cool, but the RAM constraints in particular made upgrades to the 512k in 1985 and the Plus (upgraded ROM and 1024kb) in 1986 a no-brainer.

I have a hard time believing that even System 6 would run on the 128K... And System 7 used up a whole MB of RAM. (Memories of juggling OSes and RAM on a Mac Classic with a whopping 2 MB of the stuff).

edit: looks like the 128K system info page is wrong, you needed a Plus for System 6 http://support.apple.com/kb/TA33972?viewlocale=en_US

"Support Discontinued 9/1/98"

not bad.

One year after Jobs became CEO.

This is not unusual for products that existed before a formal support lifecycle was established. Microsoft often uses a 12/31/2001 date for such products.

So think about this...the top-of-the-line iMac display currently supports 2560x1440 (or 3686400 pixels) while the original mac supported 512x384 (or 196608 pixels).

If you spread out that increase over the course of 30 years, you are adding 10.5% more pixels each year, while cutting the price by ~60% (from Macintosh to present iMac)

It's been a crazy 30 years!

Add to that that the starting bit depth was 1 vs 24 bits today (you miss the factor of 24). The memory was expensive then.

The original Mac had a screen buffer of 24KiB, which isn't enough to even hold half of a Retina-scaled iOS icon.

The original Mac's display was 512x342, not 384.

Amazing to compare what fit into 128k back then vs how much memory it takes simply to run the Calculator app now...

You could run System 7 on a 128K Mac? That's crazy.

Only with a ROM and RAM upgrade (effectively making it a plus). It wasn't cheap, as these components were soldered to the motherboard.

I just love that it lists the BTU/hour that the machine generates.

It is however not needed as the wattage is also available.

"Last Modified: Apr 19, 2012"

What does the big 64 KiB ROM chip ?

The whole OS, including e.g. the "QuickDraw" graphics routines.

The later OldWorld-ROM Macs went so far as to have stuff like QuickTime in ROM. The Mac Classic even had a whole System 6 boot disk in ROM you could activate if your harddisk was dead!

I understand that significant parts of the OS code were burned into ROM in order to free up RAM, which was more expensive. Code for things like the window manager, etc. Later versions of the OS patched bugs in the ROM by loading the patches into RAM. A rather inventive design at the time.

Not only later versions. The original ROM already was patched: http://www.folklore.org/StoryView.py?project=Macintosh&story.... Mac OS was the only OS I know of that had a system call for replacing system calls.

AmigaOS had "library vectors" (see Exec.library SetFunction) for patching ROM libraries too.

The 128KiB of RAM was painfully insufficient even with so much shifted to ROM: text files couldn't be more than a few pages in length. And there was no backing store you could reliably swap OS components into either, because the machine had a single floppy drive and no hard disk, and the floppy disk had to come out to allow disk copying.

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