Nextor 2.1.1 beta 2: it's pull request review time!

Paragon (1198)

13-01-2022, 13:21

Hi Nextor fans. I'm preparing a new release of Nextor, this one will be 2.2.1 beta 2 as you probably have guessed.

I have created a set of open pull request in GitHub which implement the changes for this new version, it would be great if you code freaks could take a look and shout as loudly as you can if you find something amiss.

Each pull request has its own detailed description, but in a nushell, the changes are:

Fix for a bug in the mechanism introduced in Alpha 1 to improve the performance of the cluster chain allocation. When deleting a file, the updated cached cluster number was being written to a random memory location (instead of being written to the appropriate place in the unit descriptor), and as you can imagine that was no good.
This is a big one: the internal implementation of the file mounting mechanism (the one you use to mount a disk image file to a drive) has been rewritten. The original implementation kept the disk image file open and accessed it via file access functions, which in theory seems like a neat approach but in practice caused hard to track bugs (since the file access functions had to be patched to be re-entrant). The new approach is sector-based: the initial sector where the mounted file begins in the host drive is added to the sector being accessed in the mounted drive. A bit more constraining (the disk image file needs to be stored across consecutive sectors now) but way more robust.
A new environment variable KILLDSKIO is introduced. When it exists and is set to "ON" the BASIC commands DSKI$ and DSKO$ will be disabled and the 512 bytes that would have been used for a disk sector buffer for those will be gained back for BASIC programs.
And a small one as a bonus: a new CALL SYSTEM2 command. This one will boot into the DOS environment loading MSXDOS2.SYS, even if NEXTOR.SYS is available. Useful when you need to get some extra TPA memory since MSXDOS2.SYs is smaller than NEXTOR.SYS.

And that's all, happy reviewing for those who are up for the challenge!

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Par gdx

Enlighted (6214)

13-01-2022, 14:40

Hi konamiman,

It is a real pleasure to see this evolving project. Request sent.

https://github.com/Konamiman/Nextor/issues/99

I shout as loudly as I could. :)

Par pgimeno

Champion (328)

16-01-2022, 12:03

Is there any mechanism to prevent disaster in case of deletion of a file mounted as device? If not, maybe keeping the file open is not such a bad idea (assuming an open file can't be deleted, which I don't know).