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OSDev Series Chapter 20 Updated

Posted: Mon Jul 20, 2009 3:01 am
by Mike
Chapter 20 of the series has been updated with more content along with a demo. The demo builds on chapter 19's demo with a TUI and a new command for reading any sector from a floppy disk. Feel free to check it out in the resources section of the site. Comments and suggestions are always welcome.

Re: OSDev Series Chapter 20 Updated

Posted: Thu Jul 23, 2009 4:12 pm
by Insightsoft
Im learning a lot...
you are my hero...

Re: OSDev Series Chapter 20 Updated

Posted: Sun Aug 02, 2009 1:23 pm
by djsilence
Hey, Mike, I've got a problem with your tutorial of chapter 20. You wrote that it is a well-known bug in VPC, but I use VMWare and when I test your demo I get such values of my zero sector: 0, 0, 0, 0xFE, 0x9, 0...

Same I get if I try to read sector 1, 2, etc. And any time displayed content of sector is the same. When I try to read not 0 drive but 1 drive I get the same. One time per hundred times I get right reading of sector. Else very often I get such error as Error reading disk...

When sector is read well - I cannot repeat reading. I mean if sector is read successfully, then I try to read some sector else - I get nothing... Just displayed message reading sector...

Chears, Daniel.

Re: OSDev Series Chapter 20 Updated

Posted: Tue Aug 04, 2009 11:10 pm
by Mike

Thanks for letting me know :D I will be doing a little more testing with it, I know there is an incompatibility with VPC currently which might be related to the problem that you described in your post.

I will post back here if anything is found. :D

Re: OSDev Series Chapter 20 Updated

Posted: Fri Aug 14, 2009 7:57 pm
by ehenkes
What is the sense of this line?

Code: Select all

flpydsk_send_command( ( ( sector + 1 ) >= FLPY_SECTORS_PER_TRACK ) ? FLPY_SECTORS_PER_TRACK : sector + 1 );

Why not

Code: Select all

flpydsk_send_command( 18 );

Re: OSDev Series Chapter 20 Updated

Posted: Sat Sep 26, 2009 10:52 am
by BlastOS
Hi there,

reading the chapter 20, I saw a mistake.
It's not very important but I post here for the accuracy of the tutorial.
In the description of the floppy drive cable you write that it's 40pins but that's wrong, fdd has less pins,34 pins...

Here is a link sowing the pinouts:

Hope it helps :D

Re: OSDev Series Chapter 20 Updated

Posted: Sat Jul 17, 2010 8:03 am
by chibicitiberiu
Nice tutorial, great work. However, you should start supporting other types of floppies (3.5", 5.25", and all sorts), also having a way to detect them (most likely the CMOS, and by the way, it could be useful to implement the Real Time Clock as well).

And another note, writing, and formatting the floppies should also be implemented...
Other than that, nice work :) thanks a lot.

Re: OSDev Series Chapter 20 Updated

Posted: Sat Aug 07, 2010 11:12 am
by Jarvix
You can do that yourself ;) Internet has all you need :D

// Jarvix