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Old 08-19-2009, 07:15 PM
TomL_12953 TomL_12953 is offline
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Default Front Panel LEDs and Other Issues

I'm not sure if these are problems or not but here goes:

When I'm running a BASIC program, the front panel lights hardly change at all unlike Rich Cini's Altair32 emulator which flashes all kinds of lights. Rich assures me his emulator is correct so I'm wondering about my replica. When I enter data from the front panel, the lights do show the proper responses so I know it is connected to the bus. I'm using a CompuPro RAM 17 64K static memory board if that has anything to do with it. There's a switch on it for using it with computers that have a front panel although the manual says not to run it that way. Any ideas? Also, when I first turn on my system, all the data lights are lit and I can't do anything at all until I hold Stop and Reset. I know it's recommended to do that but nowhere does it say it's mandatory. Is there some kind of power-on reset that's supposed to happen? If so, It isn't happening with my system.
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Old 08-19-2009, 07:59 PM
Geoff Harrison Geoff Harrison is offline
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Originally Posted by TomL_12953 View Post
When I'm running a BASIC program, the front panel lights hardly change at all
The blinkenlights can be pretty subtle on an 8800, and different memory boards can modify the effect. For example, MITS' 4k board tends to hold all the data lights on when a program is running. It's fairly simple to modify the board to cause the data lights to flicker, but again, it's just a subtle twinkling rather than a distinct flashing.

Quote:
Originally Posted by TomL_12953 View Post
Also, when I first turn on my system, all the data lights are lit and I can't do anything at all until I hold Stop and Reset. I know it's recommended to do that but nowhere does it say it's mandatory. Is there some kind of power-on reset that's supposed to happen? If so, It isn't happening with my system.
There was a post in the altaircomputerclub list recently about this (http://groups.yahoo.com/group/altair.../message/1771). Bottom line: no one ever clearly stated in a manual that you must hit stop/reset, but yes, you should. There is no power on reset that puts the entire machine in a known state.

Geoff.
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Old 08-19-2009, 09:30 PM
TomL_12953 TomL_12953 is offline
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Quote:
Originally Posted by Geoff Harrison View Post
There was a post in the altaircomputerclub list recently about this (http://groups.yahoo.com/group/altair.../message/1771). Bottom line: no one ever clearly stated in a manual that you must hit stop/reset, but yes, you should. There is no power on reset that puts the entire machine in a known state.

Geoff.
Thanks for the quick reply! That's my problem. You say "you should" but my system doesn't work at all (no entry possible from front panel, no switches work at all) until I hit Stop and Reset. I was just wondering if this was normal behavior.
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Old 08-20-2009, 12:50 AM
Geoff Harrison Geoff Harrison is offline
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Originally Posted by TomL_12953 View Post
Thanks for the quick reply! That's my problem. You say "you should" but my system doesn't work at all (no entry possible from front panel, no switches work at all) until I hit Stop and Reset. I was just wondering if this was normal behavior.
Yep, mine is the same. Although, since it starts up in an unknown state, once in about 20 or so restarts it comes up looking like it's ready to go, but I just automatically hit stop/reset to be sure.

Some third party CPUs (CCS 2810, for example) had an option to jump to a specific address on power on to run a boot loader or system monitor. Does anyone know if they worked correctly in the 8800? I thought the stop/reset salute was necessary to bring the front panel into a working state, not just the CPU board.

Geoff.
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  #5  
Old 08-20-2009, 01:43 AM
marty marty is offline
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Talking Front Panel

Hi all;
Yes, the reset puts all sorts of things in a known state on the Front Panel and on the CPU Board, and I think That the 'Stop' puts the 'RUN/STOP Flip-flop' in a known state, like 'stop' , instead of in the 'RUN' mode....
THANK YOU Marty
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