OSDev Series Chapter 20 Updated

[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.

[Insightsoft]

Nice...
Im learning a lot...
you are my hero...

[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.

[Mike]

Hello,

Thanks for letting me know 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.

[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 );

[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:
http://pinouts.ru/Storage/InternalDisk_pinout.shtml

Hope it helps

[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.

[Jarvix]

You can do that yourself Internet has all you need

wiki.osdev.org/CMOS
wiki.osdev.org/Floppy
etc

// Jarvix