Screen memory mapping

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Screen memory mapping

Shiv
Isn't 8000 all memory address for screen or more than 8000?

I work on Fill.asm project and when i type a key, the whole screen seems to be turned black. But when i test with FillAutomatic.tst, it fails. I'm guessing 8000 might not be enough to fill the whole screen.

Could anybody help me? Thank you for looking this.
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Re: Screen memory mapping

WBahn
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I'm having to read between the lines a bit here since you don't say what the 8000 is referring to. I'm guessing that you have a loop that is writing to one RAM address and that you are executing that loop 8000 times.

If so, run your program manually and look very carefully at your screen and you will probably see that not everything is black.

Go back and examine Section 4.2.5 in the text. Here's a hint -- the KBD address is located immediately after the last address in the SCREEN area.

Your confusion stems from thinking of 8K as being 8*1000. But in computerland, the K multiplier is 2^10 and not 10^3. I couldn't find where in the text this is pointed out, so I'll point it out here.
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Re: Screen memory mapping

Shiv
Thank you for replying.

Yes, the screen wasn't turned black completely, there were few space lines remain white at the bottom.
I totally was misunderstanding about 8K as you mentioned. So, the numbers of the screen memory address should be 8*2^10 = 2^13. You cleared my confusion, thank you so much.
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Re: Screen memory mapping

WBahn
Administrator
So glad I could help. Have fun on the rest of the journey.