Search found 34 matches

by ehenkes
Tue Jun 22, 2010 10:21 pm
Forum: Beginning OS Development
Topic: IRQ question
Replies: 7
Views: 11294

Re: IRQ question

https://prettyos.svn.sourceforge.net/sv ... nel/time.c

Code: Select all

uint8_t PackedBCD2Decimal(uint8_t PackedBCDVal)
{
    return ((PackedBCDVal >> 4) * 10 + (PackedBCDVal & 0xF));
}
by ehenkes
Tue Jun 22, 2010 6:17 pm
Forum: Beginning OS Development
Topic: Floppy disk write problem
Replies: 1
Views: 4324

Re: Floppy disk write problem

FDC_CMD_EXT_MULTITRACK <--- that makes no sense for single sectors
by ehenkes
Mon Jun 21, 2010 7:24 pm
Forum: Beginning OS Development
Topic: Floppy disk write problem
Replies: 1
Views: 4324

Floppy disk write problem

I have a problem writing sectors to the floppy: Is here something wrong? 519 if (operation == 1) // write a sector 520 { 521 flpydsk_dma_write(); 522 flpydsk_send_command(FDC_CMD_WRITE_SECT | FDC_CMD_EXT_MULTITRACK | FDC_CMD_EXT_DENSITY); 523 } 524 525 flpydsk_send_command(head << 2 | CurrentDrive->...
by ehenkes
Sun Jun 13, 2010 5:04 pm
Forum: Beginning OS Development
Topic: which operations need "motor on" at floppy disk device?
Replies: 2
Views: 5453

which operations need "motor on" at floppy disk device?

which operations need "motor on" at floppy disk device?
- calibrate
- seek
- read/write

Is that enough?
by ehenkes
Sun Jun 13, 2010 2:47 pm
Forum: Beginning OS Development
Topic: How do you really get started with OS development?
Replies: 24
Views: 29748

Re: How do you really get started with OS development?

dd for windows is efficient for binary copying from one media to another one.

There is an interesting example: how to "format" a usb mass storage device (e.g. pen stick) with the FAT12 file system? :D
http://www.c-plusplus.de/forum/viewtopi ... 1a02c.html
by ehenkes
Thu Jun 03, 2010 4:16 pm
Forum: Beginning OS Development
Topic: How do you really get started with OS development?
Replies: 24
Views: 29748

Re: How do you really get started with OS development?

If you want to start with OSDev you have to learn two things:
1) debugging
2) find and read "specs"

Otherwise you get lost and ask a lot of foolish questions. :mrgreen:
by ehenkes
Sun May 02, 2010 9:28 pm
Forum: Advanced OS Development
Topic: USB2.0 mass storage device
Replies: 0
Views: 18294

USB2.0 mass storage device

http://forum.osdev.org/viewtopic.php?f=1&t=21888

I look for people having experience in implementing USB2 with mass storage device (USB2, SCSI commands). We have first success, but need to stabilize that for all Simulations, Sticks, real PC. Please contact us.

http://www.c-plusplus.de/forum/viewforum.php?f=62
irc.euirc.net #PrettyOS
by ehenkes
Mon Feb 15, 2010 11:48 pm
Forum: Beginning OS Development
Topic: MS Virtual PC
Replies: 2
Views: 7249

Re: MS Virtual PC

I think the hub of the wheel is the autoinit bit of the DMA, which does not work reliable with real hardware and is not supported by MS Virtual PC. Hence, the best way is to avoid it and initialize just before reading/writing data between floppy and DMA:
http://wiki.osdev.org/DMA#Floppy_Disk_DMA_Programming (see my comment)
http://www.c-plusplus.de/forum/viewtopi ... is-15.html
by ehenkes
Mon Nov 09, 2009 5:03 pm
Forum: News Discussion
Topic: Chapter 21 Demo Released
Replies: 12
Views: 41002

Re: Chapter 21 Demo Released

The VPC compatibility bug

Could you please comment about this bug? (before/after)
by ehenkes
Tue Oct 27, 2009 11:01 pm
Forum: Advanced OS Development
Topic: Starting OS w/o floppy
Replies: 5
Views: 15640

Starting OS w/o floppy

What's the best way to start such an OS, if you have not got a floppy disk at your computer. How can you boot from and load from/save to USB memory stick in an easy way. Can you show me a link to an USB driver?
by ehenkes
Sat Aug 29, 2009 8:09 pm
Forum: Beginning OS Development
Topic: MS Virtual PC
Replies: 2
Views: 7249

MS Virtual PC

Is there a solution to use MS Virtual PC instead of Bochs for reading and writing data with the FDC of Demo 15 in chapter 20? Currently, it does not work. I think this was already mentioned in a thread, but I did not find it. :?
by ehenkes
Sat Aug 29, 2009 4:46 pm
Forum: Beginning OS Development
Topic: Chapter 20, Demo 15, how to write a sector to floppy disk?
Replies: 6
Views: 12664

Re: Chapter 20, Demo 15, how to write a sector to floppy disk?

With some PCs you get return values of 0 for all bits, but reads data. What can be the reason? printformat("Return Values of read_sector:\n"); int j; for(j=0; j<7; ++j) { int val = flpydsk_read_data(); // read status info: ST0 ST1 ST2 C H S Size(2: 512 Byte) printformat("%d: %d "...
by ehenkes
Thu Aug 20, 2009 7:32 pm
Forum: Beginning OS Development
Topic: What is wrong on some PC with this 1st stage BL?
Replies: 12
Views: 19333

Re: What is wrong on some PC with this 1st stage BL?

Yes, that is irritating, but at a tester partner there was the same effect. :?
by ehenkes
Thu Aug 20, 2009 4:11 pm
Forum: Beginning OS Development
Topic: What is wrong on some PC with this 1st stage BL?
Replies: 12
Views: 19333

Re: What is wrong on some PC with this 1st stage BL?

I tried to put the stack below the boot sector at linear 0x7C00, but you are right its stack segment times 0x10. Thus, I was content with this ss = 0x9000. 8)
RAM is 2 GB.