It's two days past the deadline, but I found an extra moment to work on my SD card interface today and I have it working!
I switched the clock output to the SD card from SH_CLK to /SH_CLK to move the rising edge of the clock to a point where …
During Retro Challenge I needed a way to run machine code on my rc2014, as BASIC was incapable of the performance needed to initialise the SD card in bitbang mode.
I didn't (and still don't) have an EEPROM burner when I first got my rc2014, and although the version of …
I'm at my deadline for RetroChallenge 2016/10 and unfortunately I'm tantalisingly close to having something that works, but not quite there.
I have the bitbang/slow mode working and generating pulses that match the output I get from my Bus Pirate when using it to talk to the SD …
As it stands my RetroChallenge entry is close to working, but not quite there.
The fast mode appears to work and I was able to decode the SPI packets sent to the SD card with OpenLogicSniffer's SPI analyser module.
The picture above shows the signals and the decoded data for …
To avoid the work done designing my SD interface being wasted I decided to verify the concept before going any further.
I used my Bus Pirate to verify that the SD card I have would respond to the commands I expected using the protocol I expected.
The Bus Pirate supports …
I've been struggling for free time this month for poking around with breadboards and other fun things. To work around this, and still (hopefully) get my RetroChallenge entry done, I decided to use a simulator so I could work on it with my laptop whenever and wherever there was time …
In my previous post I promised to show the previous implementation of my Z80 SD interface, and to run through the problems which I intend to fix this month.
The 74138 (U1) in the top left of the schematic is used to detect and decode IO reads and writes from …
I decided to join in with ` <http://www.wickensonline.co.uk/retrochallenge-2012sc/>`__Retrochallenge 2016/10 this October. I'm also hoping this will provide some incentive to write more posts and updates about other projects once I'm back into the swing of things!
My goal for this Retrochallenge is to finish …