why does ti contain op1set1, 2, 3 and 4

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puromtec
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Posts: 43
Joined: Fri 07 May, 2010 11:00 pm

why does ti contain op1set1, 2, 3 and 4

Post by puromtec »

I am really just curious, why does ti offer op1set1/2/3/4. I understand that op1set1 will help setup the exponent and real flag in floating point to make creating floating point values a little easier. But, why also have 2 3 and 4, as well as system routines? Just seems odd.
Xeda
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Posts: 42
Joined: Sun 06 Feb, 2011 7:08 am

Re: why does ti contain op1set1, 2, 3 and 4

Post by Xeda »

It's because it was easy, that's all. The code might have been something like:

Code: Select all

Op1Set0:
      xor a
      jr SetXXOP1
OP1Set1:
      ld a,1
      jr SetXXOP1
OP1Set2:
      ld a,2
      jr SetXXOP1
OP1Set3:
      ld a,3
      jr SetXXOP1
OP1Set4:
      ld a,4
SetXXOP1:
      <<code for bcall(_SetXXOP1)>>
I do that, too when I only need to add a few bytes to create something else useful. For example, in BatLib I have a call that multiplies DE by BC, so I added an ex de,hl to make another call called Mult_HL_by_BC :D

I have not checked those bcalls, but I have looked at the calls like OP1ToOP2 and that is how they work, so I imagine that is how the OP1Setx calls work.
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