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 data is valid before the write even takes place.
Feeler: Mac Portable max-out RAM upgrade
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 full expansion, I have to pick off the DTACK line myself and decode everything myself.
I did find a discrepancy. the book I think is incorrect on the pin diagram of the expansion slot for RAM. the board itself if you look at a picture, shows a staggered 1, 2 like normal IDC pin numbering system.
Well the book shows the pin numbering as linear and is way different than what I measured with a DMM. odd....
It appears BOTH the portable and backlit portable GLU will only decode and DTACK 5MB of address space. So for full expansion, I have to pick off the DTACK line myself and decode everything myself.
I did find a discrepancy. the book I think is incorrect on the pin diagram of the expansion slot for RAM. the board itself if you look at a picture, shows a staggered 1, 2 like normal IDC pin numbering system.
Well the book shows the pin numbering as linear and is way different than what I measured with a DMM. odd....
Thank you for satisfying my curiosity. I guess the immediate DTACK makes sense. 16MHz is what? 62.5 nanoseconds. Plenty of time for the SRAM to get the data out there while the CPU 'sees' DTACK and waits for the next clock edge to access the data bus.
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 century.
Now I am just waiting on the CPLD stuff. Coming from china so thats going to take a century.
Dog gone it. Well that packing method is no good then. My apologies. Will you be able to use those?
Any suggestions, lacking spare trays or proper tubes? Individual little anti-static packets, maybe?
How bad was the pin damage?
Hmmm. I wonder if there are tubes for 48 pin TSOP chips.
I have a velcro strap rack designed for shipping TSOPs.
it has 26 I think AM29LV320 FLASH TSOPs in it.
Those TSOPs I cant use, maybe I can ship the carton to you and you can figure out what to do with those chips.
the carton can be used to truck TSOPs back and forth once I get these expansions working.
As far as these, I think I can use them. Just have to fix the pins.
it has 26 I think AM29LV320 FLASH TSOPs in it.
Those TSOPs I cant use, maybe I can ship the carton to you and you can figure out what to do with those chips.
the carton can be used to truck TSOPs back and forth once I get these expansions working.
As far as these, I think I can use them. Just have to fix the pins.
Hey TechKnight… So I've got a Kingston 4MB card for a 5126 and three.. yes that is three weird RAM upgrades that bring my 5120's and 5126's up to 7MB.. I haven't figured out how to get them to 9 but I am sure it's possible.. These are stackable RAM chips that go in the PDS slot.. I forgot the manufacturer name.. I have the original boxes for the RAM too.. It doesn't use the RAM slot like I said.. it uses the PDS slot.. I've posted about them before.. The have little dip switches on them and I have the instructions on how to set them if you add more stackable cards.. I will take some pics of them tomorrow and email them to you.. I would be very interested in more RAM upgrades for my others… I have a 2MB and already got a quote on the chips for the vacant spots that uni did on his from a bad board.. I think I found them for like 3 bucks.. or so.. I have the company that sells them's info.. They are almost exactly the same.. And this is for the 5126.. I haven't looked into the 5120 RAM board yet… I'll get you the info tomorrow...
the only way to expand it past 5MB is to use the PDS slot.
Well, I got other ideas....
Well, I got other ideas....
I am sure you do Techknight.. I am sure you do!!! 
Sign me up to purchase your product!!! I know others that will buy too.. And of course I bet a ton of people on here.. Uni probably know's a zillion as well...
Sign me up to purchase your product!!! I know others that will buy too.. And of course I bet a ton of people on here.. Uni probably know's a zillion as well...
I'd be in for two also, it sounds like it's coming along well.
my CPLD development board came in today. Cool little thing. Now just waiting on the JTAG.
better start working on the PCB layout, but I need to come up with a footprint/pin for that RAM IC in eagle.
Last thing is ordering the buffer ICs.
better start working on the PCB layout, but I need to come up with a footprint/pin for that RAM IC in eagle.
Last thing is ordering the buffer ICs.
Technight... we are all chomping at the bit!!! Can't wait!!!
Guys, I have a discrepancy here.
Designing cards and drivers for macintosh, and the original portable developer notes list the slot like this:
but...
Guide to the macintosh family hardware lists the slot like this:
The pinouts between the two are very different. (same signals though)..
any thoughts??
Designing cards and drivers for macintosh, and the original portable developer notes list the slot like this:
but...
Guide to the macintosh family hardware lists the slot like this:
The pinouts between the two are very different. (same signals though)..
any thoughts??
I started another thread in the hack section, Since its more of a project than a "Feeler" now.