How Apple's developers reflashed Mac ROMs in the '90s

I was working on an 8-bit system back in this same time period. We couldn&#x27;t afford flash devices and the kit required to reprogram them. But we did a similar trick with an extra write pin located near the ROM socket, then used a special daughterboard filled with SRAM that replaced the ROM and also touched the write line. Now we could just use our cheap debugger and blow an image into the address space the ROM used.<p>Only downside was that you lost the image on power down, so I can see why EEPROM was more important to Apple in developing their systems.

&gt; I would love to see an example of what these PDS cards looked like, if anyone out there has some inside knowledge they would be willing to share!<p>The only thing that came to mind were these Newton development boards from about that era. I believe they were more or less Newtons shoved into one of the slots of a Quadra-like machine (perhaps the PDS slot?).<p>My memory of that era is fuzzy though.

What blows my mind is how active the collector community is about these machines. These machines are over 30 years old—they’re so old they’re not even regularly on eBay anymore.<p>I still have and cherish my 8600, the very first Bad Motherfucker computer I ever managed to obtain. :)

Adjacent: does anyone have a good article describing how Macs used to boot from ROM? Not just some sort of BIOS but the full MacOS System. It seemed like a really neat feature, but IIRC quickly became useless because there was no way to update the ROM so you&#x27;d end up loading the OS from disk to get the latest version.

From the color scheme, I assume the author of the utility really liked Squeak.

The Performa 630CD was my first Mac and it warmed my heart to see its picture. That feeling went away quickly as I saw it being used as guinea pig for ROM shenanigans. Save that Performa!

&gt; By the way, I actually succeeded today at hacking the code of Flasher to erase and program modern flash chips. It required a lot of 68k assembly work, but luckily I had a good reference to start from in my USB SIMM programmer.<p>And then, jealousy intensified, I close the tab and go back to debugging my MVC webapp.

I know there&#x27;s a rule against posting titles like &quot;How To Do X&quot; in <a href="https:&#x2F;&#x2F;news.ycombinator.com&#x2F;newsguidelines.html">https:&#x2F;&#x2F;news.ycombinator.com&#x2F;newsguidelines.html</a>, but in this case the title doesn&#x27;t make sense without the &quot;how&quot; - of course Apple&#x27;s developers reflashed Mac ROMs in the 90s, they had to do it as part of their job, the article is about <i>how</i> they did it.

&gt; <i>”See that thing that suspiciously looks like a CD-ROM drive on the left? It’s not. It’s a blank cover … I pressed the button thinking the CD tray would come out. If you push the button hard enough, it gets stuck back in there.”</i><p>Pretty weird and un-Apple-like to have a physical eject button at all. The mid-90s were such a weird time to be alive.

is this the actors carl hewitt (rip)?