Hi all,
I suspect some folk here have done this before.... :-)
My desktop CRT (over 10 years, but not what I'd consider vintage!) has been
ailing for some time, with the picture getting darker and darker despite
having the brightness at 100%. It's still good for high-contrast stuff such as
black text on white background, but forget trying to pull details out of most
photos, for instance.
Heater voltage seems good at 6.4VDC / 350mA (it's derived from the PSU in this
monitor rather than the flyback section), but I'm considering boosting it a
little and see if it improves things, obviously shortening the life of the
tube in the process.
Question is, what's a sensible amount to over-run things by? Say I aimed for
around 10%, is that too much and going to kill the heaters in next to no time,
or so little that unlikely to really make any useful difference?
cheers
Jules
>Message: 14
>Date: Mon, 22 Nov 2010 15:41:05 -0800 (PST)
>From: Fred Cisin <cisin at xenosoft.com>
>Subject: RE: possible ic source
>
>On Mon, 22 Nov 2010, John Foust wrote:
>> Even today, Google Maps says the difference in Chicago's favor is
>> 13 hours 9 minutes versus 13 hours 32 minutes, but I bet you can drive
>> at a higher speed from El Paso than you can from Chicago.
>
>In the mid 20th century, Texans would brag, "You can ride a train all day
>and still be in Texas"
>Pennsylvania: We used to have a slow train, also.
>Alaska (1958): ?Quit bragging, or we'll cut Alaska in half, and then Texas
>will be the THIRD largest state.
>
There is a story I have heard that there was a WWII POW camp in Texas?for captured German pilots. The captured pilots were trucked from the ship in port to the camp. ?They thought that they were being driven around in circles to break them, because they could not believe that someone could drive so long and still be in the same country, let alone state.
Bob
Hallo
Do you have HP64000 5 1/4 diskettes with Assembler / Lindker 6809 and
also Emulator software 6809 ?
Do you send such dikettes ?
I there any other way to get HP64000 compatible disks ?
thanks in advance
schoch alfred
medatec austria
/
/> I ought to have pointed out that most times doing what i do wastes a
> little time, and in fact it owuld heen fine just to plug the board in and
> power up. But this is amply compensted for by the time saved when thigns
> go very wrong.
Yeah and when you've gone through all the steps, learned what all the chips
are for, plugged them in one by one and finally the whole thing does actually
work, the satisfaction is much bigger.
> Do I conclude from this that the first byte read --- in fact all bytes
> read -- are always 0?
Exactly. And I just figured that they all are framing errors. Here's my test
program that should exit when it reads a byte that has no framing error:
LDAA #%00010000 ; like in jbug (8bit, np, 2stop, no divide)
STAA $8008 ; acia control reg
READ LDAA $8008 ; acia status reg
ASRA
BCC READ ; branch unless data ready
BITA #%00001000 ; check framing error
BNE READ ; branch if framing error
SWI
It never exists no matter what audio file. The only thing that does work is
that the data ready bit stays cleared as long as there is no audio at all.
So it at least reacts to the fact that there is audio or not.
> I assume this ACIA is a 6850. What does the data input do when you play
> the audio file? Where does the Rx Clock signal come from, and is it correct?
Yes, it's a 6850. I measured with a volt meter, I don't have a scope (yet).
RxD and RxC are high when no audio and they both drop to around 2V when audio is
supplied, so I guess there's at least some signal. Also RTS is low as it should.
Something weird that I don't understand is that simply adjusting the audio volume,
the apparent voltage measured on the RxD changes more or less proportionally...
this is supposed to be digital and FM ?
Wim.
At 10:41 AM 11/22/2010, Rich Alderson wrote:
> He received a telegram from the
>home office asking him to visit a customer in Texarkana who was having trouble
>with one of their products. He telegraphed back that they should send someone
>from Chicago, since they were much closer to the customer.
Even today, Google Maps says the difference in Chicago's favor is
13 hours 9 minutes versus 13 hours 32 minutes, but I bet you can drive
at a higher speed from El Paso than you can from Chicago.
- John
A friend just called to tell me he was wandering through Tanner
Electronics' store in Texas, and had spotted some bins of ics sorted by
type, including a variety of floppy controller chips. I've added
them to my mental list of possible sources of older ics, and figured
others might be interested as well.
De
> From: Al Kossow <aek at bitsavers.org>
>
> A while back, part of an AMD 2900 development
> system showed up on eBay. My copies of the software
> surfaced today, so the .imd images are up under
> http://bitsavers.org/bits/AMD
>
> They are CP/M 1.4, as I recall.
Thank you. Might be extremely useful some time if I get around to using my similar system. On the other hand I might sell it, in which case having the image available on BitSavers has got to make the system more viable for someone. Just too busy with my 1301 in the summer and with my 1301 gate level simulator in the winter at the moment. Perhaps I should do a 2900 based computer with the 1301 architecture. Maybe an ICL 1900 and/or an Elliott 920.. The 920 ATC actually was 2900 based but I doubt the microcode has survived, though the early 920s would be simple as they only had 16 instructions - before they ballooned for CISC and then were reduced again for RISC. I suppose with a writable control store I could do anything from a Babbage Analytical engine or a Turing machine to the latest systems, though maybe not at full speed. Some of the more interesting machines (to me) like the ICT 1302 would be impossible because alas no full documentation of the instruction set survives. I have marketing information on it which amazingly actually lists some of the extra instructions but its far from complete and omits most of the actual function codes. Maybe I should ask the designer of the 1301 if he knows what his successors did.
Enough rambling, at least it was on topic.
Roger Holmes.
Technical Director, Microspot Ltd
Developers of CAD and Graphic software for the Apple Macintosh
Paxton writes:
> I really tried to search out used computer places in Vancouver BC with
> vintage equipment when I visit.
If you build a wayback machine that will take you to the 1990's, the UBC
SERF sales were way above excellent. Everything from mass spectrometers
to near-complete working -11 and -8 systems.
I'm told they don't happen anymore :-(.
Tim.
