Hey everyone, I ma repairing a Sun 100U computer, and am having some
issues I would love some help with. I am using a bwtwo video card with
the Sun 100U CRT (its a 17" HD B&W phillips CRT). I am getting an image
showing a successful boot, but I am getting a split double image (like
split screen but the same image on both sides). Any ideas what is
causing this, a frequency issue? Any jumpers/settings on the video card
which may inadvertently cause this? Could it be a CRT issue?
I just need some moral support, as my unit currently doesn't work. Probably an easy fix. I do have the whole deck out though, floppy cabinet, expansion cabinet. Monitor.
> Date: Wed, 8 Aug 2012 23:22:20 +0200
> From: "Rik Bos" <hp-fix at xs4all.nl>
> To: "General Discussion: On-Topic and Off-Topic Posts"
> <cctalk at classiccmp.org>
> Subject: HP 98xx series cassette EOT-sensor fix : war story
> Message-ID: <001001cd75ab$e8416670$b8c43350$(a)xs4all.nl>
> Content-Type: text/plain; charset="us-ascii"
>
> Lately I acquired some HP 9865 cassette units and a HP 9821A three cassette
> drives suffered from 'slow running'
>
> I found out the LDR's used in the EOT sensor are causing this behavior, the
> used LDR's are from the NSL314 type which is practically unobtainable.
>
> The NSL314 is a IR-sensitive CDSe type LDR, replacing it with a standard low
> resistance LDR doesn't do the trick, the LDR needs to have a resistance
> lower then ~5k at low light.
>
> The most of the cassette drives also suffer from bad sensor bulb, replacing
> the bulb by a white LED doesn't give enough light to do the trick.
>
> The combination white LED and new LDR isn't working because the LDR
> resistance isn't getting low enough.
>
> The sensor amplifier circuit needs to be modified to work correct, I did
> this by creating Wheatstone's bridge by adding a grounding resistor to the
> LDR input.
>
> Adding a series resistor of 10k to LDR input and changing the feedback
> resistor from 18k2 to 100k made the amplifier work correct with the
> combination white LED and 'normal' CDS type LDR.
>
Why wouldn't you use an IR LED?
Jon
[Forwarded by lawrence at ljw.me.uk with links obfuscated]
From: Tothwolf <tothwolf at concentric.net>
To: General Discussion: On-Topic and Off-Topic Posts
<cctalk at classiccmp.org>
Subject: SGI IRIS 1400 mkboot and Ideal III tape images
Date: Wed, 8 Aug 2012 17:39:24 -0500 (CDT)
[2nd attempt to send this to the list.]
I just found these tape images again while sorting out files and thought I'd
post links here so these can be mirrored. I dumped both tapes about 10 years
ago when I got them with the SGI IRIS 1400. These will probably only be of use
to someone with one of these machines, but no one else I spoke with back when I
got the machine had this software.
I'm not sure if the mkboot tape is usable or not but I don't remember having
any trouble reading either of the tapes. The tape.0 and tape.2 files both read
as valid cpio archives, but tape.1 doesn't. These three tape.x files were
separate partitions on the QIC tape.
http://strudel (dot) ignorelist (dot) com/~tothwolf/classiccmp/SGI-IRIS-1400/MKBOOT-IRIS-1400.tar.gz
MKBOOT TAPE INCLUDING /USR
PARTITION FOR THE IRIS 1400
DATE 4/1/88
TAPE NO. 063/SG/005
http://strudel (dot) ignorelist (dot) com/~tothwolf/classiccmp/SGI-IRIS-1400/IDEAL-III.tar.gz
IMAGE VISUAL SYSTEM
SINGER Link-Miles
27 NOV 1987
IDEAL III
CUSTOMER RELEASE TAPE
FOR IRIS 1400 64 COLOR
INCLUDING:- RUN FILES, MENUS, HELD FILES,
KERMIT UTILITY FILES AND COMSEG D/BASES
TAPE NO. 063/SG/004
A number of years ago now, I ran across a bit of a find at a computer recycler's. It's an old Motorola evaluation kit for the 6800. I thought I had the CPU board, an interface board and a couple memory boards - it turns out I had two pairs of the processor board and interface board. I've fired up at least the one pair, and they work perfectly. I loaded some code into memory using the hex keypad and it ran fine. Anybody else run across these?
I just posted the MITS Altair 8800 Power supply specs with a link to the
schematic on my web site, if you went the sensible route and bought
something new with the same characteristics the original.
http://vintagecomputer.net/browse_thread.cfm?id=486
Bill
After looking at nice computers at Ames and the Computer History Museum, a
though occurred to me: What is the slowest/oldest supercomputer still in
operation?
--
David Griffith
dgriffi at cs.csubak.edu
A: Because it fouls the order in which people normally read text.
Q: Why is top-posting such a bad thing?
A: Top-posting.
Q: What is the most annoying thing in e-mail?
