I have a few boot roms in a 9312 bootstrap terminator that I can't identify.
The manual lists most boot roms, but these particular ones are not listed in
the manual I have. Anyone know?
760A9 - PR - PC05 (this one I could find in the docs)
786A9 no clue
788A9 no clue
787A9 no clue
I'm hoping one of them is an RL02 rom :\
Jay West
The 1N4742 is a 1w part which at 12 volts is well within the amperage
ratings of a 7812.
That's the way I'm going to go. Thanks.
-----Original Message-----
From: cctalk-bounces at classiccmp.org [mailto:cctalk-bounces at classiccmp.org]
On Behalf Of Allison
Sent: Friday, July 15, 2005 8:55 AM
To: cctalk at classiccmp.org
Subject: Re: Solid State Music V1B question
>
>Subject: Solid State Music V1B question
> From: "Cini, Richard" <Richard.Cini at wachovia.com>
> Date: Fri, 15 Jul 2005 08:39:42 -0400
> To: "'General Discussion: On-Topic and Off-Topic Posts'"
> <cctalk at classiccmp.org>
>
>All:
>
>
>
> I'm playing around with the SSM V1B video board in my Altair,
>and I have a question about errata and board modifications, specifically
>with regards to the +12v power supply.
>
>
>
>I have three boards. One is "condition unknown" and two are working. The
>+12v regulated supply consists of a small-value series resistor, a zener
>diode and a cap. One of the boards has a 100 ohm, 1/4w resistor which is
>charred and when operated, continues to smell. The other working board has
a
>220 ohm resistor and the same zener diode and appears to work fine with no
>smell. The manual specifies a 100 ohm resistor and a 1N4742 diode.
>
>
>
>The "condition unknown" board has a 7812 regulator soldered to the pads
>replacing the resistor and the diode. From what I can tell from the
>schematic, the +12v is used only for the character generator chip. When
>turned on, I get a display full of well-formed garbage, which is probably
>just that it's displaying the random data in buffer memory.
>
>
>
>Does anyone have a view on what the best kind of repair might be?
>
>
>
> Thanks.
>
Rich,
The best fix is the three terminal regulator. The resistor and zener
diode works well but the correct value of resistor is dependent on the
raw 12+ volt power on the S100 buss. Since I've seen that bus run from
barely 15V (marginal for three terminal regulator) to as high as 22V
the right resistor varies greatly. I'd speculate (I don't know which
character rom) on the required 12V power needs that the 100ohm is
plainly too low and maybe 220 is right. If the resistor is too low
the Zener diode will overheat and if too high the regulation is poor.
Zener diodes have power ratings like many parts and if exceeded they
fail. Using a three terminal regulator eliminates a lot of guessing.
Allison
All:
I'm playing around with the SSM V1B video board in my Altair,
and I have a question about errata and board modifications, specifically
with regards to the +12v power supply.
I have three boards. One is "condition unknown" and two are working. The
+12v regulated supply consists of a small-value series resistor, a zener
diode and a cap. One of the boards has a 100 ohm, 1/4w resistor which is
charred and when operated, continues to smell. The other working board has a
220 ohm resistor and the same zener diode and appears to work fine with no
smell. The manual specifies a 100 ohm resistor and a 1N4742 diode.
The "condition unknown" board has a 7812 regulator soldered to the pads
replacing the resistor and the diode. From what I can tell from the
schematic, the +12v is used only for the character generator chip. When
turned on, I get a display full of well-formed garbage, which is probably
just that it's displaying the random data in buffer memory.
Does anyone have a view on what the best kind of repair might be?
Thanks.
Rich
FREE for S&H, University of Michigan, 1" thick Volume 10 on BASIC, dated 1971. It documents how to program BASIC from their terminals running from a IBM 360 model 67.
,George
ICS at Core.com
Does anyone have any information about Pro-Logs "System 2" operating system
for STD-Bus machines? I've got a i286-based Pro-Log 7892-03 CPU that has a
rom labled "SYSTEM 2<cr>MODEL 60 BIOS", and a 7171B-02 system support card
with a rom labled "SYSTEM 2<cr>ROMDISK H". Google hasn't been very helpful,
other than to indicate that it existed.
Ken
Well, I have good news and I have good news... (and just a little bad news)...
I have now erased a bajangle of eproms, I have quite a few Basics burned
and lots of spare blank carts, so they'll hit the mail soon. I have
tomorrow off, so I'll prolly pack/address/ship then. If not, definitely
over the weekend. Tuesday nite was going to be my "Pack'em up nite" but the
wifeypoo got a line on a good job, so it was transformed into "Rewrite the
Resume nite."[1] Wednesdays are a PITA for me (to work at 7:30am, get out
at 8:30 pm or later) so I rarely feel like doing anything after work. Of
course, my LCD monitor "went blank" Tuesday nite, so I had to figure out
the cause of that last nite... I was a grumpy dude by 11:00 pm. ;-) Turns
out the LCD monitor died... :-( I grabbed my wife's monitor and am using
that temporarily until I can get a new one in.
I did test a basic cart in my HHC, and it seems to work fine, *except* I
think my RAM's a bit wonky, as once I create a program, then exit BASIC, it
thinks I have 2 bytes of free memory left. Weird. It might also be a
limitation as to *which slot* the chip goes into - I didn't diddle with
that. Or... I don't believe that the internal batteries are functioning, so
it might be a power problem causing the wonkeyness... Anyway, the Basic
itself comes up and it takes immediate commands just fine, and I've entered
in 2-3 line programs that run fine until you exit basic, then it thinks
there's no free memory left. Like I said, weird.
Anyway, I'll send out individual emails tomorrow with the status of each
order, but I wanted to let everyone know I didn't forget 'em!
;-)
Laterz,
Roger "Merch" Merchberger
[1] After a 10-year hiatus from the workforce, it was quite a job!
--
Roger "Merch" Merchberger | Anarchy doesn't scale well. -- Me
zmerch at 30below.com. |
SysAdmin, Iceberg Computers
Hi Richard
You most likely won't have any troubles but it is
recommended to have a 1uF to 10uF cap at the input lead.
These things can oscillate in the 100KHz to 1MHz range.
I remember trouble shooting a burn-in board that
was running about 20 amperes and going on and off
at about 900 KHz. I was surprised that they'd not
gotten a visit from the FCC. I guess the antenna was
not that effective. I didn't have a radio handy to
try but I suspect it would have been noticeable
at close range. ( the voltage was 15Volts with about
100 regulators )
Dwight
>From: "Cini, Richard" <Richard.Cini at wachovia.com>
>
>Dwight:
>
> Thanks. I will add the back-biased diode. Should I also add a small
>filter at the inout of the regulator or is that not needed since the
>distance between the source point (buss connector) is fairly close to the
>regulator?
>
>Rich
>
>-----Original Message-----
>From: cctalk-bounces at classiccmp.org [mailto:cctalk-bounces at classiccmp.org]
>On Behalf Of Dwight K. Elvey
>Sent: Friday, July 15, 2005 1:07 PM
>To: cctalk at classiccmp.org
>Subject: Re: Solid State Music V1B question
>
>Hi
> The typical rail voltage is around 18 volts some place. This
>should be on the order of 1/3 watt someplace for the resistor.
>The 1/4W resistor is way too small. I'd tend to think that
>you might be better with the 220 ohm resistor. The diode of
>1W is a maximum of 83 ma. I'd suspect that you only need about
>1/10 that much to get reasonable regulation. Even at 15V
>input, a 1.8K would be enough. One would need to figure
>how much current the video chip needed, before selecting the
>right value resistor.
> Since you have one board with a three terminal regulator,
>you might add a 10 ohm resistor to the input lead of the
>regulator to work as a temporary current sensor. The regulator
>draws some current but it is usually small. Add about 50%
>to this value and then add 8ma for the diode. From this
>you should be able to calculate a reasonable dropping
>resistor. Figure a minimum supply of about 15 volts and then
>figure the wattage with the 22 volt level.
> Or, as was suggested, go to a 3 terminal regulator for all.
>I've seen a number of negative regulators fail, when used
>under minimum load. I suspect this is actually caused
>by back current when the supply is turned off. Any filtering
>capacitors after the regulator may hold longer than the
>input filter capacitors. This causes significant back current.
>When using a 3 terminal regulators under a minimum load, as
>you'll be doing, I suggest that you add a 1N4001, back biased,
>from the input to the output lead ( for a positive regulator,
>band on the input lead ).
> When working for a company doing embedded machines, we saw
>this problem and we had no more returns after adding the
>diode.
>Dwight
>
>
>>From: "Cini, Richard" <Richard.Cini at wachovia.com>
>>
>>All:
>>
>>
>>
>> I'm playing around with the SSM V1B video board in my Altair,
>>and I have a question about errata and board modifications, specifically
>>with regards to the +12v power supply.
>>
>>
>>
>>I have three boards. One is "condition unknown" and two are working. The
>>+12v regulated supply consists of a small-value series resistor, a zener
>>diode and a cap. One of the boards has a 100 ohm, 1/4w resistor which is
>>charred and when operated, continues to smell. The other working board has
>a
>>220 ohm resistor and the same zener diode and appears to work fine with no
>>smell. The manual specifies a 100 ohm resistor and a 1N4742 diode.
>>
>>
>>
>>The "condition unknown" board has a 7812 regulator soldered to the pads
>>replacing the resistor and the diode. From what I can tell from the
>>schematic, the +12v is used only for the character generator chip. When
>>turned on, I get a display full of well-formed garbage, which is probably
>>just that it's displaying the random data in buffer memory.
>>
>>
>>
>>Does anyone have a view on what the best kind of repair might be?
>>
>>
>>
>> Thanks.
>>
>>
>>
>>Rich
>>
>>
>>
>>
>
>
Dwight:
Thanks. I will add the back-biased diode. Should I also add a small
filter at the inout of the regulator or is that not needed since the
distance between the source point (buss connector) is fairly close to the
regulator?
Rich
-----Original Message-----
From: cctalk-bounces at classiccmp.org [mailto:cctalk-bounces at classiccmp.org]
On Behalf Of Dwight K. Elvey
Sent: Friday, July 15, 2005 1:07 PM
To: cctalk at classiccmp.org
Subject: Re: Solid State Music V1B question
Hi
The typical rail voltage is around 18 volts some place. This
should be on the order of 1/3 watt someplace for the resistor.
The 1/4W resistor is way too small. I'd tend to think that
you might be better with the 220 ohm resistor. The diode of
1W is a maximum of 83 ma. I'd suspect that you only need about
1/10 that much to get reasonable regulation. Even at 15V
input, a 1.8K would be enough. One would need to figure
how much current the video chip needed, before selecting the
right value resistor.
Since you have one board with a three terminal regulator,
you might add a 10 ohm resistor to the input lead of the
regulator to work as a temporary current sensor. The regulator
draws some current but it is usually small. Add about 50%
to this value and then add 8ma for the diode. From this
you should be able to calculate a reasonable dropping
resistor. Figure a minimum supply of about 15 volts and then
figure the wattage with the 22 volt level.
Or, as was suggested, go to a 3 terminal regulator for all.
I've seen a number of negative regulators fail, when used
under minimum load. I suspect this is actually caused
by back current when the supply is turned off. Any filtering
capacitors after the regulator may hold longer than the
input filter capacitors. This causes significant back current.
When using a 3 terminal regulators under a minimum load, as
you'll be doing, I suggest that you add a 1N4001, back biased,
>from the input to the output lead ( for a positive regulator,
band on the input lead ).
When working for a company doing embedded machines, we saw
this problem and we had no more returns after adding the
diode.
Dwight
>From: "Cini, Richard" <Richard.Cini at wachovia.com>
>
>All:
>
>
>
> I'm playing around with the SSM V1B video board in my Altair,
>and I have a question about errata and board modifications, specifically
>with regards to the +12v power supply.
>
>
>
>I have three boards. One is "condition unknown" and two are working. The
>+12v regulated supply consists of a small-value series resistor, a zener
>diode and a cap. One of the boards has a 100 ohm, 1/4w resistor which is
>charred and when operated, continues to smell. The other working board has
a
>220 ohm resistor and the same zener diode and appears to work fine with no
>smell. The manual specifies a 100 ohm resistor and a 1N4742 diode.
>
>
>
>The "condition unknown" board has a 7812 regulator soldered to the pads
>replacing the resistor and the diode. From what I can tell from the
>schematic, the +12v is used only for the character generator chip. When
>turned on, I get a display full of well-formed garbage, which is probably
>just that it's displaying the random data in buffer memory.
>
>
>
>Does anyone have a view on what the best kind of repair might be?
>
>
>
> Thanks.
>
>
>
>Rich
>
>
>
>
