Wednesday, June 6, 2012
CFFA1 and BASIC Integration
I've been working on integrating the CFFA1 flash card with my ports of Enhanced BASIC and MS BASIC for the Replica 1 so that SAVE and LOAD commands will support BASIC programs.
Using the CFFA1 APIs to save and load memory to and from files is quite straightforward. To simplify the process of getting the filename from the user, I simply prompt for it.
I had problems getting loading of programs to work reliably on either version of BASIC. It was not clear what range of memory needed to be saved and restored. It's further complicated by the fact that the CFFA1 firmware uses a lot of locations in page zero that are also used by EhBASIC so they need to be correctly saved and restored.
After a few evenings without success it was becoming frustrating and I was ready to set it aside for a while. However, I made a posting to the EhBASIC section of the forums at 6502.org and a couple of helpful forum users gave me some more details I needed to get it working. It now seems to be working well with Enhanced BASIC. I haven't yet resolved all the issues with MS BASIC.
I've been watching an original Apple 1 that is up for sale on ebay. The auction will end tonight and is currently bidding at $35,100.
Another Apple 1 is going up for auction at Sotheby's in a week. They estimate it may sell for $120,00 to $180,000. One last year sold for over $200,000.
I also added a new command to JMON to allow writing data to memory, similar to Woz Mon's ":" command. This was the only feature that it was really lacking. I also have a few more features and enhancements planned.