New RAM card, prototype Mac Portable, demo System 7 | Hacker News Reader

New RAM card, prototype Mac Portable, demo System 7

oldvcr.blogspot.com

The Mac Portable was my first computer, which my dad brought back from work but never used. It was on this machine that I learned how to program, starting with Basic (I believe it was MS-Basic back then) and then moving on to Hypercard. Those were the days when knowledge was gained through magazines and the accompanying floppy disks, loaded with shareware. What a remarkable era it was, and how much progress we have made since then!

The whole system was designed for long battery life and standby time. That’s why it didn’t have the backlight LCD, had an enormous battery (reading https://support.apple.com/kb/sp140?locale=en_GB, it only delivered 5W, tops, though), and used static RAM.

I guess this expansion used dynamic RAM with on-board refresh logic, but the page isn’t clear (to me) on that.

> I guess this expansion used dynamic RAM with on-board refresh logic, but the page isn’t clear (to me) on that.

It's a little bit of both. The RAM on the expansion card is an ISSI pseudo-SRAM:

https://www.digikey.com/en/products/detail/issi-integrated-s...

In short, it's DRAM on the inside, but all of the refresh logic is internal, so it behaves as if it were static RAM.

Hey cool, my RAM card is being mentioned on hacker news!

You're right, the card uses PSRAM because non-synchronous SRAM chips basically aren't available new any more. I didn't want to have to troll the depths of (semi-questionable) new old stock parts sites and went with new chips.

This design was assisted by my good friend techknight, original designer of the 8 megabyte RAM card for the mac portable.

(author) It worked great. You deserve it! Thanks for making it.

I just bought a dozen new PDIP Alliance AS6C4008 512k x 8 asych srams from Mouser from stock. If you go surface mount, I think there are even more options.

>PSRAM because non-synchronous SRAM chips basically aren't available new any more.

AS6C6416 4Mx16. Someone even uses it raw on 5V bus with no level translation, just tiny Lattice LC4064V cpld for address decoding. https://www.amigalove.com/viewtopic.php?f=6&t=1689 https://hackaday.com/2021/01/08/the-amiga-1000-still-receivi...

Yeah, I noticed that chip and didn't give it a second look. It's more than 3x the cost of the PSRAM solution, and that would have driven up the price of the RAM card higher than planned. So sure, it exists. And that's about all I have to say about it.

Impressive that Apple keeps support documentation for such old products.

I believe there’s a place for a portable with high travel keys, built like a tank and with e-ink display.

There’s certainly a lot of nostalgia, hipsterism and fetishism in the appeal of such product (I'm guilty of all 3), but maybe it’s not all there’s to it. Maybe it could be truly useful as well.

One of my favorite laptops ever was the Toshiba T3100.

https://en.wikipedia.org/wiki/Toshiba_T3100

At the time that keyboard combined with the super-readable display was magic. LCDs were a bummer after working with this.

Oh, yeah...EL displays are awesome on the eyes. The T3100, the Grid and the Compaq portable with an EL display were so nice back in the day. Unfortunately, EL displays are extremely power hungry, so it was not to last. I actually have an EL VT-220 terminal clone in my homelab.

Whatever the appeal is, I have it too. I've been playing with the idea of fitting a e-ink and someing RPi-ish into a Toshiba T1000 formfactor (I have a dead one). Another project on the pile. I think for cranking out writing, it could be a winner.

I think lots of us have a similar idea. I thought of something like this too.

> The Macintosh Portable was the first portable (I hesitate to say "laptop") Mac,

Was it though? I recall a high school math teacher who carried his Mac SE around in a special rectangular backpack.

(author) Good point, I added "from Apple" to be explicit. There were certainly the third-party ones floating around by then.

Technically, Apple did sell the iic as an optional portable/luggable as well[0], with an add-on LCD screen, case, and a built in handle. Granted, at this point we're just getting into the weeds.

[0]https://en.wikipedia.org/wiki/Apple_IIc#Portability_enhancem...

As featured in the movie 2010 (released in 1984).

The Apple IIc was not a Mac

There was a backpack for that Mac form factor. I believe that makes it a 'luggable' though, not a portable.

The original Mac had a built-in handle for carrying it around (and Apple sold a bag with a shoulder wrap for doing that), too, but unlike this device, it wasn’t battery powered.

So, it was portable, but not “a portable”.

In the IBM compatable world, portable was definitely a category, and it didn't include batteries. From my one encouter with a compaq portable, I think it was a lot harder to carry than a Mac SE, but at least you could attach the keyboard to the front for transport, and no mouse needed. If you had the Mac shoulder bag, I guess it probably had room for a keyboard and mouse though.

"Never trust a computer you can't throw out the window."

--t. Woz

Anything is that kind of portable if you're strong enough.

I'm remembering walking three and a half miles carrying a VAXStation from the rail station to home... :)

Why are the RAM cards angled like that? I'd expect rectangles...

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