I have plans to use most of these ICs @ 12MHz SPI so i made proper shield instead of breadboard because some guy found it too noisy to work properly that way(link at bottom).
The shield is drilled a bit off axis as i did make it fast with 550W handheld drill
First tests with built in libraries reach sort of low speeds, probably due to latency growing with bus speed, getting ~20kB/s with byte transfer for both writing and reading @ 12MHz and ~50kB/s for 4MHz SPI
23LCV512-I/P 64kx8bit SRAM 20MHz SPI – TESTED WORKING up to 12MHz
IP12B256I-TU 32kx8bit SRAM 20MHz SPI
IP12B512C-TU 64kx8bit SRAM 20MHz SPI
todo: # do some more tests..speed!!!
# find fastest library or make own, this guy juiced off ~120kB/s
I was quite sure that this wont work, but we have been forced to try.. Not that much..
Normally the LAN is got over FTP and UTP cables, aka the twisted ones.. Yeah, the twisted wires.. Or even twisted pairs of twisted wires.. Cat6e has 6 twists per inch..
But using old 12 x 1.5mm² AC mains cable with no twists which is 20 to 30 meters long, is under ground and dated to late 70′s or 80′s must fail..or..?
why this could work?
1st: i used only 10Mb/s mode
2nd: we were totally lucky
update 2/2017: i will be finishing this project soon!
HOW IT BEGAN.. Some time ago neighbor brought me to look on his granddaughter’s „broken“ ACER Extensa 5630Z notebook. When i saw BIOS and booting i told him its not broken, only Windows is.. So i took it to fix the Win Vista on that machine. The problem was black screen after system boot, with the mouse cursor in the center of screen. Thats all it did, only thing working and able to set a window is 5x shift, giving a typo helper we sure wont ever need, no ctrl+alt+del, no nothing. I tried to fix it with many ways i found on the net, nothing. Internal logs are clear except for some irrelevant things, explorer and so on was set fine in registry, i was desperate on that.. The point is i had to fix it in place because nor neighbor, nor i have Vista install DVD and both of us wont ever download it.. The System Restore doesnt work as i expected, ending with errors. There is no way to make the Windows work except for reinstall..yeah