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RAMdisk CP/M 2.2 (MDERA)


Experienced Member
Mar 21, 2014
Well, I'm at the point of putting design to keyboard and writing code. I'm going nice and slow to check things out in stages. I'm putting 'testing stubs' in the code so as not to screw things up too much. Format the RAMdisk (MDFRMT), put in the dummy directory entries, make sure they are there (MDDIR), upload the latest MDERA code, run the test, find the errors, figure out what I did wrong and fix it, rinse, repeat. I'm probably on the sixth design I've had just trying to figure out how I want the program to flow, even before starting to write the code. All part of the hobby.
Do you have a way to write the RAMdisk to a file, or read a file back into the RAMdisk so that you can restore the RAMdisk on boot or similar? Like creating an image of it?
Not really. It isn't a problem since all my current STD bus Z-80 is for is a prototype and test bed at this point. Once I get things fully functional, then I will start porting it to my S-100 based system. Similar design, but the RAMdisk will have all NVRAM. My current system may even become a 'smart terminal', or who knows; hobbies never get completed....
Well, it's been awhile and kind of got sidetracked. But I now has the erase program of the suite working for the most part. I can erase an entry that is not write-protected and only consumes one directory entry (file less than 2048 bytes). The next feature I need to add is to throw an error if I try to erase a write-protected file. The last feature is to erase a file that consumes multiple directory entries (files greater that 2048 bytes, but less than 32,768 bytes). That upper limit was just a random pick since that is 16 directory entries. Theoretically, by using a single byte to record the sequence number, I could store a file over 522K, but that will never happen. 32K should be quite adequate.