> What is the best way to get a copy of the manual and/or schematics from CHM?
I'll talk to the powers that be. From memory, they have a complete CDC 6600 print
set (about 4 feet of 8x11 binders) so I suspect the console will be in there.
On 21 Jan 2004 15:55:40 +0000, Gordon JC Pearce <gordonjcp(a)gjcp.net>
keyed in:
> On Wed, 2004-01-21 at 15:43, William Donzelli wrote:
>>> The problem with NOS is that the glass is slightly porous and the
>>> valves
>>> will have gone a bit soft by now.
>>
>> This is basically false.
>
> Well, I call it as I see it. I have literally dozens of new old stock
> valves, in their original cardboard sleeves. Some are useable, some
> are
> absolutely shagged. It's not all just cheap brands, too.
Space heaters generally decay due to the escape of gasses into the
envelope. This can be caused by two mechanisms: outgassing and leakage.
When the tube is manufactured care is generally taken in choosing the
metals/glasses to ensure that they have a low gas content. Initially
the envelope is evacuated under fairly high vacuum and baked to allow
any adsorbed gasses to outgas. The longer the baking, the better the
vacuum. Consequently, the cheapies will use cheap metals/glasses and
shortcut the bake-out time. Finally, the tube is sealed and the getter
is fired (i.e. evaporated). The getter is an active metal that you find
plated around the base of the tube. The getter generates a high vacuum
in the tube by combining with active gas species and trapping the inert
ones. Since getter is expensive, cheap tubes go short on this item with
the subsequent outgassing of the guts causing the decrease in
conduction.
The second mod of failure is by leakage of helium. Although this gas
exists at about 5 ppm in air it abhors a vacuum and will over time leak
into the tube. Glass is permeable to helium. (HeNe lasers fail due to
the leakage of He. You can take a dead HeNe and resurrect it by placing
it in pure helium for several weeks...). The inclusion of gas into a
tube is evident by the blue glow one sees in a tube that is going over
the hill. Moral: don't own tube equipment if you're in the balloon
business.
As an aside, during the '60s is saw a control computer being developed
for the military that consisted of several hundred tubes integrated
into a volume of approximately 20x20x20 cm. The "tubes" were fabricated
by forming cavities in ceramic layers with beta emitters for cathodes
and plates and interconnection evaporated onto the ceramic. These
layers were then stacked to form the controller. The average tube was
on the order of a 1/2 cm^2 or less. This baby didn't glow, but I would
like to have the bucks that went into its manufacture...
Claude Ceccon
Fred N. van Kempen <waltje(a)pdp11.nl> wrote:
> > Noone wants the boards ???
> Nope.
I do! Though I won't be able to do much with a VAX 7000 because of how DEC
mucked up its architecture unfortunately (using an Alpha bus in a VAX etc.), I
would be interested in any and all XMI and/or VAXBI boards.
MS
>On Jan 20, 14:23, Joe Abbott wrote:
>> Does anyone have images of Rom 0 and Rom 1 for
>>Cromemco SCC S100 single board Z80 computer?
after which, Pete wrote:
>I'm very disappointed to find my SCC's single EPROM
appears to be
>something the previous owner made for his own
purposes -- it only has
>36 bytes of code in it. Sorry, Joe. I guess this
one was bought
>without the monitor/BASIC ROMs, which were optional.
Just my luck! Thanks anyway, Pete. Hopefully someone
out there will be able to help.
I'd bet yours contains the code to disable the onboard
roms and jump to the floppy boot rom. My System Zero
manual mentions this and lists the asm code as well as
a hardware mod. Might be why there doesn't seem to be
many of these roms around.
Joe
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I found this in a pile of scrap boards the other day.
<http://www.classiccmp.org/hp/misc/hitachi.jpg>. It looks like it might be
some kind of evaluation board. Does anyone know exactly what it is? It has
the Hitachi logo on it along with the number H40LCEV00/133. The ZIF socket
contained the IC at the bottom. It's a Hitachi HD44857E. I haven't been
able to find out what it is either.
Joe
>
I don't have a reference for exactly "DT uL909759"
--
I'm in the process of scanning the 1969 f data book and have finished the
logic part. The scan will be up at www.bitsavers.org/pdf/fairchild/_dataBooks
later today.
Found this today. It's about 6 1/2" x 7" and has 8 30 pin SIMM sockets
and a 60 pin ribbon cable header on it. It's marked 701-2214-001. Does
anyone know which Data I/O machine it's for?
Joe
I have a SGI Indigo and Indigo II along with a pile of Sun stuff. I'm
wondering if I can replace all the funky monitors with one modern multisync
SVGA monitor. Anybody know of any reason that this won't work, or have any
recommendations about what kind of video adapter I need or where to get
one? (13W3 to SVGA).
Joe
Does anyone have a manual for an M7891 (128kx18 MOS memory)?
What at the switch settings? or more specifically, what do the 9 pos &
4 pos switches do? (address, no doubt)
I have one which shows a red light when I try to read/write from the
console odt. I just want to make sure the switches aren't set
incorrectly before I declare it broken.
And are their any prints on the net? (I couldn't find any)
thanks!
-brad
