That was fast... RAM is already here. Looks like most suffered pin damage though, so well see.  Now I am just waiting on the CPLD stuff. Coming from china so thats going to take a…

techknight said: Well the backlit has a timing requirement of 0-wait states. Meaning the DTACK has to be handled almost instantly upon a chip select or address strobe. Cli…

I didn't have any luck finding them on his page either... I went to an locally owned Ace Hardware here in Boise to get some keys cut for work and found some brown 3M replacements …

I found the designing cards and drivers for macintosh family online.  It appears BOTH the portable and backlit portable GLU will only decode and DTACK 5MB of address space. So for…

the UDS/LDS data strobes go low after valid data is on the bus to be written. So when these lines get toggled, and address strobe gets toggled for a write, I know then that the dat…

Well the backlit has a timing requirement of 0-wait states. Meaning the DTACK has to be handled almost instantly upon a chip select or address strobe. When I am outside of the 5MB …

Just checking to see if I understand this. On one Portable type (non-backlit) there's an ASIC which does house-keeping for RAM accesses.   When the RAM address space is accessed, …

I am. There was a video card I think . Hap has one

I am not aware of anything ever using the PDS slot on a portable. 

So a full upgrade plus empty PDS slot? Was there good PDS upgrade board or something useful?  If so, this RAM upgrade would be quite popular!

Really? Hap has a rom card. For one of his portables.

And this is the reason why. So they can decode the entire address space and use up all 9MB.  But I wont need to do that. all the address/data lines are broken out at the RAM conne…

Some portable ram upgrades are in the Pds slot and not the ram slot

I got the CPLD development breakout board on the way along with the JTAG. Once I get the RAM from trag, ill mount those up on a TSOP to DIP Adapter then I can make a simple wire-wr…

5 Meg total.  That explains the logic ICs near the 8 PRAM ICs on the backlit portable, that logic circuitry decodes the 1 Meg of onboard memory, plus it handles the DTACK and 0-wa…

is that 5 meg plus the one onboard or 5meg total? great progress .

ok, I answered my own questions. I found this note:  http://cdn.preterhuman.net/texts/computing/apple_hardware_devnotes/Portable%20(BackLit).pdf this basically explains the diffe…

The question is.. why cant you interchange? The bus is the same... The max ram also should not matter. The core chips are the same. Gttmfh only discussed one slot. And they dont …

I know my backlit ram did not work in my non backlit then was reminded that they were different so I did not interchange at all after that. Also the max ram on each is different. …

Can't imagine someone wanting a card that isn't maxed out. That would just be kinda nuts

I do want to make the card hold at least 8 Megs. But you dont have to populate all 8 megs. if you want just 1 meg, thats fine. put 1 chip on there, etc etc... 

Thats just it, I dont know. Which is why I am debating whether its worth the effort of designing a card or not.  I know I want 2 of them for myself. But the rest, is up to demand.…

trag said: That makes good sense. That's the dream. Run out of chips. Clean out a tiny portion of my attic. They are cool chips. A tiny piece of me squeals, "No, hang on to …

techknight said: The Toshiba has a weird little setup which is A-1, and its shared with I/O16. It appears I/O16 becomes A-1 in byte mode. But A-1 is not A1. And it doesnt rea…

techknight said: The portable and backlit portable both use 100ns ram. This is my first time making a ram expansion so if I have the logic wrong its a simple matter of moddi…