is it possible to rebuild old c64 hardware enhancements?

On Thu, Mar 5, 2009 at 17:03, Gene Buckle <geneb at deltasoft.com> wrote: I have been thinking about the following: It is (relatively) easy to interface to a MMC/SD/SDHC card, and they're quite cheap (<$10) for smaller sizes, small meaning around 1Gig. Interface code and circuits can easily be googled - for example, there are a few projects to read/write to them from the Arduino. ("circuit" being a 2-resistor voltage divider on the 5V TTL lines going to the SD card, and straight connection to the 5V inputs since 3.3V is sufficient for the TTL threshold to be satisfied) I don't think the I2C featuers of the ATmega are used since the Arduino does not support it in their libraries, so all IO is usually bit-banged. (I may be wrong on this!) Given this, can one hook a SD/SDHC card to the Amiga parallel port, and then write a "sdhc.device" that presents a block device that can be put into the Mountlist and be accessed by dos.library or one of the ms-dos capable libraries (messydos?) and thus present a non-bootable mass storage device for the amiga? So, you boot with a custom workbench disk, that loads the driver, mounts the SDHC card and then startup-sequence hands control over to a script on the SDHC card. ISTR this was commonly done for romless drive addons on the 500 - and I had such a setup for my 1000, where my bootup workbech disk loaded the janus drivers and then handed control over to a MFM hard disk in the Sidecar. I never did any coding on my amiga to that level, and don't know if I could pull this one off aside from building the hardware and maybe the I2C code to talk to the SD card. (Hint: old PC floppy ribbon connectors make great makeshift SD card sockets!) But would any real amiga hacker be up for that? Joe. -- Joachim Thiemann :: http://www.tsp.ece.mcgill.ca/~jthiem