[Coco] Can anyone verify an error in the NitrOS9 tech manual?

[Bill Pierce]

Dave, what you would have to do is check the nitros9 source for the fseek function and see what is actually being used.
I always use seek in C so I haave no idea which regs it's using :-)

 

 

Bill Pierce
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-----Original Message-----
From: Dave Philipsen <dave at davebiz.com>
To: CoCoList for Color Computer Enthusiasts <coco at maltedmedia.com>
Sent: Sat, May 20, 2017 7:45 am
Subject: [Coco] Can anyone verify an error in the NitrOS9 tech manual?

I think I have found what appears to be an error in the NitrOS9 Technical Manual on page 145.  This page explains the use of the F$Seek system call which repositions a file pointer.  The entry conditions of the system call in the original OS9 Level 2 Technical Reference are:A = path numberX = MS 16 bits of desired file positionU = LS 16 bits of desired file positionThe reference to using the user stack pointer in this case seems illogical since the U pointer is used for a pointer to the user memory area in an OS9 program and you normally would not want to disrupt it.  Logically, one would think that this is a typo and the 'U' should be replaced with 'Y' above.And if you read the NitrOS9 Technical manual on page 145 it appears that this 'typo' has been corrected as the entry conditions read:A = path numberX = MS 16 bits of desired file positionY = LS 16 bits of desired file positionHowever, I have found that indeed the correct usage is as described in the original OS9 reference using the user stack pointer, U.  I believe that there is no 'typo' in the original manual and that the NitrOS9 manual is wrong.  Therefore, in most cases, the programmer must save the value in "U", make the system call, then restore the value in "U".Can anyone verify this?Dave-- Coco mailing listCoco at maltedmedia.comhttps://pairlist5.pair.net/mailman/listinfo/coco