Altair 8800 SN221148A received, factory assemble status confirmed

[Marty]

Hi All;

Leiy, can You do me a favor, this is for K1atn..
Can You post the following, voltages from the three Transformers ?? and Voltages from the Buss both without Boards and with Your Boards in it ??

THANK YOU Marty

 

[leiy]

Hi All;

Leiy, can You do me a favor, this is for K1atn..
Can You post the following, voltages from the three Transformers ?? and Voltages from the Buss both without Boards and with Your Boards in it ??

THANK YOU Marty

You are welcome.

Since I'm not so professional. Please indicate which point I should measure, please mark red rings on the photo so I can measure the proper voltage for you.

 

[Marty]

Hi All;
Leiy, Thank You for your response..
I do NOT know how to do the Red Ring thing..
But, on page 62 of the Altair Assembly Manual, it shows all of the connections..
Anyway on the Black connector Block, that You show in Your picture.. Set Your Voltmeter to DC to somewhere above the 50 volt range and put one probe on the Bottom screw which is Ground.. And put the other probe on each of the four screws above that last one.. One at a time and record those voltages, with All Boards in and with NO Boards in..
Next, switch Your Meter to AC and Measure the between the two "Y" connections, and record that voltage for T3, Measure between the two "G" connections, and record that voltage for T1 and Measure the voltage between one of the "W" and one of the "R" connections and record that voltage for T2.. These are on the right side of the Power Supply Board, looking from the front of the computer.. The Power Supply Board just sits below the Black Block You Measured DC from..
I hope this makes sense..
If You cannot Measure the input voltages from the Transformers, then don't worry about it and I hope that Kt1an understands and If He need those reading can ask for them..

THANK YOU Marty

 

[leiy]

Hi All;
Leiy, Thank You for your response..
I do NOT know how to do the Red Ring thing..
But, on page 62 of the Altair Assembly Manual, it shows all of the connections..
Anyway on the Black connector Block, that You show in Your picture.. Set Your Voltmeter to DC to somewhere above the 50 volt range and put one probe on the Bottom screw which is Ground.. And put the other probe on each of the four screws above that last one.. One at a time and record those voltages, with All Boards in and with NO Boards in..
Next, switch Your Meter to AC and Measure the between the two "Y" connections, and record that voltage for T3, Measure between the two "G" connections, and record that voltage for T1 and Measure the voltage between one of the "W" and one of the "R" connections and record that voltage for T2.. These are on the right side of the Power Supply Board, looking from the front of the computer.. The Power Supply Board just sits below the Black Block You Measured DC from..
I hope this makes sense..
If You cannot Measure the input voltages from the Transformers, then don't worry about it and I hope that Kt1an understands and If He need those reading can ask for them..

THANK YOU Marty

Hi, Marty

I mean "red ring" is small indicator you can mark on photo so I can measure the voltage.

I've read your instruction. I can measure the voltage in my 221876K Altair 8800, the S-100 boards in 221876K are relatively easy to detach (boards in 221148A are so tight in slot, that are very hard to plugin and pullout, and that is too risky to broke the board pillars). I will have multi-meter tomorrow and measure it in working 221876K

Cheers, Leiy.

 

[Marty]

Hi All;
Leiy, Thank You for Your response..

"" I mean "red ring" is small indicator you can mark on photo so I can measure the voltage. ""
I knew what You meant, I just don't know how to do that.. I have never done anything with photo's except copy them..

"" I've read your instruction. I will have multi-meter tomorrow and measure it in working 221876K ""
That's fine..

THANK YOU Marty

 

[leiy]

Hi All;
Leiy, Thank You for Your response..

"" I mean "red ring" is small indicator you can mark on photo so I can measure the voltage. ""
I knew what You meant, I just don't know how to do that.. I have never done anything with photo's except copy them..

"" I've read your instruction. I will have multi-meter tomorrow and measure it in working 221876K ""
That's fine..

THANK YOU Marty

Hi, Marty

Here's the result from 221876K

=================

with six boards attached and ROM monitor running (CPU board, four 16K SRAM boards and one Turnkey board.)

10.8V
17.1-17.2V
7.5-7.6V
10.5V
<Ground SCREW>


without board attached:

17.6-17.7V
20.7V
10.6V
10.6V
<Ground SCREW>



=================


The AC power lines are too underneath, I can't measure the AC line without tear-down power supply board and some transformer. It is too risky as I'm not a professional for this, Sorry.

=================

 

[Marty]

Hi All;
Leiy, Thank You for doing this..
I am sure that there are others that need this information and the pictures.. So, Thanks again !!

THANK YOU Marty

 

[Corey986]

Ok I'm really confused by your last picture. Maybe I missed a pic. But how are you removing the other motherboards from the chassis? Are they not jumper wired in to the first motherboard? Also could be a trick of the light, but the attached motherboard looks like a rev-1. It looks thick and dark green. I have only seen rev-1 boards like this. Actually I have seen rev-1 boards in natural and dark green. When you take the chassis off and look underneath. What does the motherboard that's attached say?

Thanks,
Corey

 

[Marty]

Hi All;

"" What does the motherboard that's attached say? ""

Ouch, Beg your Pardon, I was comfortable there..

THANK YOU Marty

 

[leiy]

Ok I'm really confused by your last picture. Maybe I missed a pic. But how are you removing the other motherboards from the chassis? Are they not jumper wired in to the first motherboard? Also could be a trick of the light, but the attached motherboard looks like a rev-1. It looks thick and dark green. I have only seen rev-1 boards like this. Actually I have seen rev-1 boards in natural and dark green. When you take the chassis off and look underneath. What does the motherboard that's attached say?

Thanks,
Corey

The 221187K rev 0 only has stock configuration, the additional s100 plate is from California computer system, I use a self made connector to connect each other.

Principally, I can also connect the 12 slots California computer plate to 23th Altair, without any damage to the original stock (But I decide never do this. I permanently place the 23th to dry glass box with humidity level <25RH)

Below is my 221876K with alot of boards populated in 12 slots plate.

 

[leiy]

Hi All;
Leiy, Thank You for doing this..
I am sure that there are others that need this information and the pictures.. So, Thanks again !!

THANK YOU Marty

You are welcome.

 

[Corey986]

Very cool idea on how to add boards without making modifications.

Just be careful how many boards you put on that stock power supply. They are undersized.

 

[Marty]

Hi All;

"" Just be careful how many boards you put on that stock power supply. They are undersized. ""
That is why I went to switchers, and that the Ripple is less.. I used the same ones that Grant used in His Replica's..

THANK YOU Marty

 

[leiy]

Very cool idea on how to add boards without making modifications.

Just be careful how many boards you put on that stock power supply. They are undersized.

Thanks for advice, I will insulate Altair Disk controller pins when I received FDC+

 

[leiy]

Finally, it fun 4K Basic happy, the computer is fully working!


Bootstrap loader before send basic to RAM.

000:    076 003 323 020 076 025 323 020
010:    041 256 017 061 032 000 333 020
020:    017 320 333 021 275 310 055 167
030:    300 351 013 000

Front penal light status when running loops.

I will test the Altair Disk, when I get hard sectored 8 inch floppy disk.

 

[leiy]

I designed a simple acrylic adapter to mount DB37 cable on backpanel DB25 holes.

The DB37 Altair Disk cable can safely connect to drive.

 

[tkc8800]

Nice work on the adapter and getting 4k Basic loaded!

 

[leiy]

Nice work on the adapter and getting 4k Basic loaded!

Thank you.

Today, I tested My Altair Disk and Altair Disk controller, run test code to enable disk successfully, it seems in working condition. I desperately need some hard sectored 8" floppy disk to do a full test.

The electric motor in Pertec drive running happily, the running sound is good!

The test code I'm used from Altair Disk manual:

After some single step, The HEAD LOAD light turns on:

The disk drive should work properly, I need some hard sectored diskette to do a final test.

 

[Marty]

Hi All;

Leiy, where are You Located, I think I asked before, I just forgot ??
I have some 8" Diskettes.. I will need to find them..
My Altair Drive Boards Quit some Years ago..

THANK YOU Marty

 

[deramp5113]

Leiy,

While you wait on hard sector floppies, your FDC+ will work with soft sector floppies and make them look like hard sector floppies. It does this by syncing to the rotational rate of the drive and generating sector pulses on the fly. You'll even see the pulses on the front panel lights as described in Note 3 in the test you just ran.

Mike