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  #21  
Old 08-07-2009, 03:27 PM
marty marty is offline
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Talking memory tests

Hi Tom;
I am not good with Arithmetic and conversions, so I'll check it on my machine, and see if it flies, I have 64K on my machine...
THANKS Marty
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  #22  
Old 08-07-2009, 03:37 PM
TomL_12953 TomL_12953 is offline
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Originally Posted by marty View Post
I have 64K on my machine...
THANKS Marty
You don't have any ROM at all? I have a 64K static RAM board but I also have I have the 88-PMC EPROM board that takes the top 2K of address space. I'd really miss it if I didn't have the Multi Boot Loader up there so I don't have to key in the bootstrap every time for paper and cassette tapes! I also have VTL-2 and the DBL (since I don't have a disk system, I won't be using that for a while) as well a monitor.

Tom L
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  #23  
Old 08-07-2009, 03:39 PM
marty marty is offline
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Talking memory tests

Hi Tom;
I tried it on my machine and it does the same thing as the origional program, it seems to work ok, it loops on the final loop indicating it ran ok... I want it to jump back to start, and it doesn't so I need to look into that..... but that will be later.....
THANKS Marty
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  #24  
Old 08-07-2009, 09:05 PM
philrrtx philrrtx is offline
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Originally Posted by TomL_12953 View Post
Maybe I'm not understanding something. 16339 should be 723 037 octal (reversed bytes)

So what's the 323 037?

Tom L
It's a typo; that's what it is. You are correct. It should be 723 037.

Phil
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  #25  
Old 08-07-2009, 10:04 PM
marty marty is offline
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Red face memory test

Hi All;
You would be correct, except that you CAN'T enter 723 into the Altair or the Imsai thru the Front Panel,, You can ONLY go as high as 377, that is the Largest octal number that can be entered into the machine.... You have to use split Octal i.e. in eight bit word lengths, and for that 377 is the hightest number that you can use ....
THANK YOU Marty
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  #26  
Old 08-07-2009, 10:29 PM
philrrtx philrrtx is offline
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Originally Posted by TomL_12953 View Post
Ah! So with my 62K RAM, I'd have 62*1024 = 63488 - length of program (45 bytes) = 63443, convert to octal = 173723, reverse bytes = 723 173 mask off upper bit = 323 173

Is this right?

Thanks for your patience!

Tom L
Looks like my 323 was correct, but the second byte should have been 077 instead of 037.

In Tom's case, I get 323 367. You can't mask off the bit; you have to write octal 173723 out in binary, split it into two eight bit bytes, then translate each of those into octal (it's a heck of a lot easier to do in hex, but the spacing of the switches on the Altair makes that more difficult to enter—works nicely on the IMSAI if you have your switch paddles grouped in fours instead of threes).
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  #27  
Old 08-07-2009, 11:21 PM
marty marty is offline
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Talking memory test

Hi phil and all;
I am an octal person my self, simply because All of the Machines that I have , have the switches arranged in octal...(my Altair and my Data General Eclipse) I would say try your hex answer on a front panel or if you don't have one, on a piece of paper, and then re-read then from the front panel in octal, yes it would be harder on a piece of paper... the 173723 , I put in my Altair Front Panel I get 367/323 in split octal...
THANK YOU Marty
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  #28  
Old 08-07-2009, 11:48 PM
marty marty is offline
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Talking memory test

Hi All;
I just entered the memory test into my Altair, and it worked at 367 / 323 and for my full memory machine 377 / 323... And they both worked.... I am waiting for my Eproms from Grant. But, I am used to entering by the Front Panel
THANK YOU Marty
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  #29  
Old 08-07-2009, 11:53 PM
marty marty is offline
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Talking hex vs octal

Hi All;
A hex and Octal listing of the 8080 op codes, is in Bug Book III pages 3-36 to 3-40.... Thanks Marty
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  #30  
Old 08-08-2009, 04:10 PM
TomL_12953 TomL_12953 is offline
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Quote:
Originally Posted by philrrtx View Post
Looks like my 323 was correct, but the second byte should have been 077 instead of 037.
In Tom's case, I get 323 367. You can't mask off the bit; you have to write octal 173723 out in binary, split it into two eight bit bytes, then translate each of those into octal.
OK, so it's like this?

63443 = 11110111 11010011 b
octal = 367 323

Reverse bytes: 323 367

and those are the two bytes I'd put in the program.

Tom Lake
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