Compass on a 4GB FAT16 partition

By SuchAGoonie

Expert (108)

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09-01-2016, 21:37

My Compass freezes when I use CTRL+D (disk menu) and then choose DIR. Caps lock still works, but nothing else does. Does Compass simply not handle large partitions well or is there an easy fix for this (preferably besides creating smaller partitions)?

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By AxelF

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09-01-2016, 23:19

What version of Compass do you use ?

By SuchAGoonie

Expert (108)

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09-01-2016, 23:21

Version 1.2.09. That's the last one, right? I bought it a few years ago.

By SuchAGoonie

Expert (108)

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10-01-2016, 20:58

Axel, did you get my email? I couldn't find a contact option on your profile, so I replied to the email that msx.org sent me.

By AxelF

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10-01-2016, 23:10

Mail received, and replied... Wink

By turbor

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19-01-2016, 23:44

Hello, I had a mail conversation with Jon (the current Compass programmer/maintainer) about this.
He is rather occupied lately with family,kids, work and life in general so I post his findings here.

He did some experimenting with a smaller FAT16 partition and found out the following...
There is a difference depending on the order of the installation of the FAT16 patch and Compass.

First case:
FAT16 allocates 1 segment of memory using DOS2 (to serve as cache?)
Compass allocates all the remaining memory using the DOS2 routines.
In this situation al seems to function normally.

Second case:
Compass starts first and reserves all memory.
Now the FAT16 patch can no longer reserve 1 segment of memory. This will not produce an error, but the cache is no longer available. In this case using DOS2 itself (or using the diskmenu in Compass) to perform a DIR it takes a huge amount of time to calculate the free diskspace. Depending upon the size of the partition up to several minutes.

I hope this info is useful in diagnosing your problem.

By SuchAGoonie

Expert (108)

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20-01-2016, 03:03

Thanks for taking the trouble to look into the problem! I've let it run for maybe two or three minutes, but not longer. The FAT16 patch is something from MSX-DOS 2, right? I'm using Nextor, but I'm guessing that Nextor also tries to allocate the memory segment.

I've made an extra 32MB FAT12 partition, and Compass can read from that without any delay or problems.