Friday, January 25, 2019

25 Years Ago: RAM Doubler Debuts

Adam Engst:

First up—check out this piece I wrote from the 1994 Macworld Expo San Francisco: “RAM Doubler” (10 January 1994). Developed by Connectix, RAM Doubler was one of the most magical utilities of the early days of the Macintosh. As its name suggested, RAM Doubler promised to double the amount of usable RAM in your Mac, and amazingly, it generally delivered.

That was a big deal back in 1994 because RAM was shockingly expensive—$300 for an 8 MB SIMM at a time when I had 20 MB in my Centris 660AV. For $50, RAM Doubler would double whatever you had: 8 MB to 16 MB, or 20 MB to 40 MB. It was astonishing.

One of the best Mac apps ever. In reading my review of RAM Doubler 2, I was amused to remember that a key feature of RAM Doubler was saving scarce hard drive space. Apple’s virtual memory required space equal to the amount of RAM, even to enable file mapping, whereas RAM Doubler could do that without needing any space. And its swap file only had to be the size of the spill, rather than the total amount of virtual memory.

Update (2019-01-28): Shawn King:

It was freaking magic.

John Gruber:

The most amazing thing, in hindsight, isn’t that compression and clever virtual memory techniques could double your memory — it’s that Mac OS was so open that something as low-level as RAM Doubler was even possible. Effectively, a Mac running RAM Doubler was running a fork of the OS — not just a subtle fork but a fork where the entire memory manager was written by a third party.

In hindsight, the lack of protected memory and disk permissions in classic Mac OS are generally only looked back upon as severe deficiencies. And there certainly were deep problems with that architecture — one app or extension crashing often resulted in the entire machine going down. But that anything goes openness also resulted in tremendous opportunities for third-party software.

4 Comments RSS · Twitter

Indeed, it was really amazing how well it worked!

Ingenious application - almost all the photographers I knew back then used Ram Doubler to help run Photoshop
25 years! Hard to believe.

I had RAM Doubler!!!! I want to say my dad bought it for my first Mac. An LC II perhaps? Pretty sure it has the required MMU supported CPU, 68030; anyway, with only 10MB RAM, fixed mind you a clever virtual memory framework sure came in handy.

This was the thing that made my Performa 450 (aka LCIII) with a grand total of 4MB of memory a usable machine.

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