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  #11  
Old 09-27-2007, 05:24 AM
marty marty is offline
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Posts: 118
Talking

Hi Grant;
I would be interested in the above listing and programs.
Thank You Marty
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  #12  
Old 09-27-2007, 12:36 PM
phe phe is offline
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Quote:
Originally Posted by Grant Stockly View Post
Do you remember the e-mail I sent you on 7/20 with the 600 DPI scan of my card! ; )
Unfortunately not until you reminded me

Quote:
Originally Posted by Grant Stockly View Post
The GD4702B chip is the chip called "4702". The 74LS259 is a LS TTL version of the 93L34.
Got it. Thanks.

Paul
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  #13  
Old 09-28-2007, 03:31 AM
phe phe is offline
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Interestingly I've searched the web for altair programs and found nothing useful. I find that pretty amazing. Well, I've written a number of programs already using the switches, so I took a crack at my own echo program. I would have guessed the program to echo characters would be:

IN 11 011 011
021 00 010 001

OUT 11 010 011
021 00 010 001

JMP 11 000 011
0 00 000 000
00 000 000

So I keyed this in via the switches and then tried every possible configuration of windows hyperterminal I could think of, all 9600 baud, with various partty, flow control, and stop bits settings. I've tried it with and without a null modem cable.

No go.

Either my program is wrong (highly likely because I used port 021 which is for data and not port 020 which is for control). But I can't find decent descriptions of how the IO ports actually work.

I wonder if the documentation was easier to come by in 1975. Or you could just attend the local computer club group.

Paul
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  #14  
Old 09-28-2007, 04:12 AM
Grant Stockly Grant Stockly is offline
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You have to reset the port and send a config byte. You also have to check if there is data waiting in the chip buffer before you try to read the serial chip.

You SHOULD check to make sure that the TRANSMIT buffer is empty before transmitting a byte, but for this test we can assume that since you first have to wait for a byte that there will be more than enough time to transmit it before a new byte has been received. Do you understand that?

Here is a sample program I just wrote. Sometime saturday night I'll get the program from my S-100 book to you.

Code:
;Serial echo program for the 8080 and 2SIO
;
.EQU CONT,0 ;CONTROL/STATUS PORT OF 2SIO CARD
.EQU DATA,1 ;DATA PORT OF 2SIO CARD
;
;
RESET:
   MVI   A, H'03   ;MASTER RESET
   OUT   CONT
   MVI   A, H'15   ;CLK/16, 8N1, RTS LOW TX/RX INTERRUPTS DISABLED
   OUT   CONT
LOADLP:
   IN    CONT      ;WAIT FOR RX BUFFER TO BE FULL
   ANI   H'01
   JZ    LOADLP
   IN    DATA      ;GET DATA
   OUT   DATA      ;SEND DATA
   JMP   LOOP
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  #15  
Old 09-28-2007, 04:14 AM
marty marty is offline
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Hi Paul;
I Don't have my notebook here with me, So I had to look it up on the net !!!
I didn't take the time to look at all there was, but this should get you started.
000 333 input
001 000 or 020 or what ever port you have
002 017
003 332
004 000
005 000
006 333
007 001 or 021 or what ever port you have
010 323
011 001 or 021 or what ever port you have or 377 if you want to use the sense switches.
012 303
013 000
014 000
(This is in octal)
Good Luck Marty
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  #16  
Old 09-28-2007, 04:38 AM
Grant Stockly Grant Stockly is offline
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H in the above program means "hex", don't treat those values as octal!

Back in the old days there were magazines and journals for programming help. Programming a computer was just the way you did things. There was basic, but in the earliest days no one even had that!

So in order to survive you just had to learn it by whatever way possible.

The most exciting thing about the kits that I build is the idea that I'm helping preserve some of the knowledge and allowing people to experience these things!
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  #17  
Old 09-28-2007, 04:41 AM
Grant Stockly Grant Stockly is offline
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Marty, you should initialize the port first. It may happen that sometimes it works but that could be just luck. You can't ever count on things being right inside the chips.
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  #18  
Old 09-28-2007, 05:01 AM
phe phe is offline
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yipee!!!! My card works. I tried your program, Grant. Here are the octal codes for it (assuming you start it at 000):

000 076
001 003
002 323
003 020
004 076
005 025
006 323
007 020

010 333
011 020
012 346
013 001
014 312
015 010
016 000
017 333

020 021
021 323
022 021
023 303
024 010
025 000


I have not tried your program yet, Marty. I'll give that a go tomorrow.

Thanks, guys!

Paul
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  #19  
Old 09-28-2007, 05:17 AM
Grant Stockly Grant Stockly is offline
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Now, even though you were basically doing what a robot could do...building the board...doesn't it just give you a great feeling of accomplishment!?

When that thing is booting basic using your several thousand solder joints all the pain and suffering will have been worth it.
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  #20  
Old 09-28-2007, 05:24 AM
Grant Stockly Grant Stockly is offline
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Paul, what kinds of other programs have you made? What resources did you used to do it? Any tips and hints for other people in your situation?
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