If you have been following along with my plans, you know that the IIcmxp consists of a 1MB SRAM memory upgrade, SDcard storage and a communications module (I’d like to support both a wired and/or wireless option). It’s hard to keep on track with a method for tackling this project as I find my self swinging from just working on one aspect of the project to trying of accommodate any of the 3 aspects .ie how they will coexist with one another. I think I have come to the conclusion to develop 3 separate projects and then figure out how to adapt them to live nicely together after the fact.
Which leads me to my next topic … as I stated before I think I have the SRAM down .. still needs to be tested as I have not wired up my original IIcmxp protoboard although i did make up a wiring map for it. The SDcard is on the back burner at the moment .. still not sure if I want to use a co-processor (like Alex used) or do it entirely in the CPLD .. which brings me to my 3rd aspect … communications options …
While I am still considering the option to use the approach like the SPI2CF project (again requiring that co-processor like Till used) … I also remembered that I bought the AirDrop-P from Fred Eady. I never did get that going after buying it … so I brought it out of moth balls, dug up the latest code from the Yahoo group and got it working with my 802.11 infra in the basement including 128 bit wep. Of course all the hard work was done for me but it took some tweaking to get things complied and runnings smoothly.
With that working I thought it would be a fun challenge to get the IIc to talk directly to the CF card for the purposes of i/o. While the A2 platform already has CF support from other vendors, these are (from what I know) all used in true -IDE mode and do not support cfio operations. I worked on some ABEL code that should let me talk to the cfio registers.
So how to test this ….. hmmm … I decided to take my IIc break out board that I used for /devsel testing and I added a few components to it … namely a CF socket and one of Justins XC95144XL CPLDs .. I decided to keep the XC9572XL already in use (wired) for /devsel, I will use the rest of the i/o in that cpld to do level trasnlation from 5v to 3.3v on any required remaining signals from the IIc (except D0..D7). The XC95144Xl will be used for the CFCard logic and SDCard logic when I get there.
and this of course needs to be wire wrapped .. my next work item then is a wiring map for the CF interface .. once thats done then I will start porting some of Fred’s routines via cc65 and we will see where she goes from there …