On 11/16/20 8:36 PM, Brian K. White wrote:
On 11/15/20 9:29 PM, Brian K. White wrote:
On 10/15/20 10:13 AM, Josh Malone wrote:
That sounds awesome, Brian! I'm excited to build one of these once the
PCB is ready.
The RAM version is now verified. FINALLY
The ROM version is not verified yet.
...aaand I just found my problem with the ROM card and have now
verified the ROM card too.
I've learned that parallel async rom and parallel async ram are both
read the same way on the bus, and so I've been able to read the contents
of the RAM card by just plugging it in to the ROM programming adapter
and having the programmer read it as if it were the ROM card.
The part that matters is just the pinout. The programming adapter
provides a pinout the same as the flash chip that's actually on the
card, so all I have to do is tell the programmer to read the kind of
chip whose pinout the programming adapter provides. Even though the
chip on the RAM card is really an SRAM instead of a the flash part, and
has a different pinout, the ram card translates the sram chip to the
WP-2 IC Card pinout, and the ROM card does the same thing. The WP-2 IC
Card pinout ends up being a common intermediate interface the same for
both cards. So you can use the rom programming adapter to read a ram
card not just the rom card. The programming adapter provides a pinout on
it's DIP pins that matches the flash chip on the ROM card, so to read
the ram card, you just have to tell the programmer that the chip is the
flash chip and ignore the chip id and just try to read. And since the
bus protocol for reading a parallel async eprom is the same as reading a
parallel async eeprom is the same as reading a parallel async flash is
the same as reading a parallel async sram... it works.
I was able to format the ram card in the WP-2, create a few text files
with the WP-2 and copy them to the ram card, and then read the ram card
on my pc.
I it's just a 128K binary blob of the raw contents of the chip, but I
can see my filenames and the file contents in there clearly.
So the obvious next step was to write that blob to the rom card and see
what the WP-2 makes of that...
Well the reading and writing worked, but the WP-2 just says "no files"
when I try to read the rom card.
So... it's still a mystery how to actually USE a rom card.
derp I just realized I wrote a 128K ram image to a 256K rom. I suspect
that doesn't matter but it's possible there's some kind of formatting
that isn't valid by just doing that.
--
bkw
--
bkw
