I've recently had some free time and decided to look at some hardware
failures in my small collection.? I fixed a couple of analog boards in
the compact Mac department, and a failed scsi disk in one of them
prompted me to test the small stash of such drives that I have.? Turns
out, about half of those marked as "working" in 2015 have failed now in
many different ways.? Oh well... sucks, but it was to be expected...
I decided to image some of the still working ones, both in the stash and
in working machines.?? The one in the vaxstation 2000 (a 1GB scsi with
5.5-2) turned out to have file system corruption (probably from? AC
power failures), which has taken a while to fix.? And then, I remembered
that said system originally came with an RD53 that has sat elsewhere for
25 years.? It passed a read test in 2005.? So I tried to see if I could
read it and maybe image it now, but no go. The disk spins up, initiates
a seek (the arm is not stuck in a gooey stop pad; I've read that this is
a common failure mechanism for Micropolis 1325's; I opened it and saw
the arm move) but then the arm returns violently (clacking) to the rest
position; it does this a number of times (two to four, usually) and then
it spins down. Applied voltages and currents remain ok as this happens.
I've seen plenty of internet content about solving the stuck arm
problem, but not this.
Looking at the datasheet for the 6809 (specifically, the 6809E that
needs incoming quadrature clock), I read that !HALT can be asserted
200nS (for 1MHz part) before falling Q and the CPU will finish the
existing instruction and then go into a HALT state as long as the HALT
line is low during the falling edge of Q.
That's the store from the datasheet, but when I am testing it, I see
that, even if I pull HALT low at the very beginning of the last cycle of
an instruction, the 6809 will not acknowledge the HALT until executing
the next instruction.
My logic is watching for IO address $ff61.? When found, it drops Q
so, to start the HALT condition, I need only:
Not that the trigger is being performed by the code, so the current
instruction (the lda) should complete and then the CPU should go into
HiZ.? What I see is:
lda $ff60 <- the next instruction
executed, and THEN the CPU goes into HiZ.
I can deal with this (Yes, I should just look at BS=BA=1, which tell
when to safely use the bus, but I don't have access to those signals for
this project), but I thought I'd see if this was known by all, or if
there is something I am missing.
brain at jbrain.comwww.jbrain.com
Next to go is a home-office setup.
Mac Performa 6214CD, PowerPC CPU, 3.5? floppy and CD drive on front face
Apple Extended Keyboard II (NO ADB CABLE)
Apple Apple Desktop Bus Mouse II (round)
Apple Multiple Scan 15 Display (matching, includes cable)
APS external SCSI hard drive enclosure and cable (Centronix on the hard drive end, DB-25 on the Mac end)
Epson Stylus Color 740 ink-jet printer with a spare (unopened) cartridge
UMAX Astra 1220S flat-bed SCSI scanner (NO CABLE - DB-25 connector)
Pile of accompanying software including at least:
Now Up-To-Date and Contact
Sad Macs, Bombs and disasters
Astra Scanner Driver
All Free to a Good Home.
You want this if:
a) you can afford shipping or pickup from San Antonio, TX, 78254, and
b) 15 years after ?Take this job and shove it? came out you finally acted on it, quit your job and set up your own home office and accounting business, and now you want to relive your glory days.
All items working when decommissioned, about 15 years back. Fred?s ingenious guarantee (?Guaranteed not to work, double your money back if it does work?) applies. Please, please, please take this as a group, I really don?t want to split it up. If I locate the missing ADB or DB25 SCSI cables in time, I?ll include them, but I?ll double the price :-).
FWIW, this was a companion of the Palm Pilot in my other post.
Reading through the April 85 issue of Byte, I came across a reference to the "S1 Operating System." In Jerry Pournelle's column on pg 361 he talks about this mysterious OS. Here is a small excerpt:
Robert Knight. formerly of
Princeton's computer laboratories. is
an old fan of my books and columns
as well as the creator of SI. which he
had running on an IBM Instruments
Anyway, my Googling turned up nothing on the OS, although I did find a Robert Knight at Princeton, but no information on stuff he's done. I will likely email him to ask about it, but wanted to ask here first if anyone knows anything about it.
Googling for "multisolutions inc. s1 operating system" turned up several mentions from ComputerWorld, an S1 operating system pin at Etsy, plus this blog post:
> One day at Burroughs I received a phone call from a recruiter. Usually I don?t give these headhunters the time of day, but this one mentioned a startup company. It was either intrigue or boredom but I decided to interview. Then I was hired to write compilers which I had been doing for about six years at Burroughs.
> The company was a small startup in Lawrenceville, NJ. The CTO was a charismatic engineer named Robert Knight. The CEO was a wealthy businessman, Charles Lombardo, who provided most of the company?s funding. Somehow, maybe because Lombardo?s wife worked on Wall Street, our tiny company, MultiSolutions Inc., actually went public. Even though they actually did not have a product or a revenue stream.
> The product, under development, was an Operating System called S1. The marketing department used the slogan ?Unix is a dinosaur, MS-DOS is a toy.? This was in 1984 and it was true that there was an opportunity for a new OS in the marketplace.
> To kill any suspense, the OS never caught on. ...
> On Feb 28, 2020, at 10:00 AM, wrcooke at wrcooke.net wrote:
> Date: Thu, 27 Feb 2020 19:20:06 -0600 (CST)
> From: wrcooke at wrcooke.net <mailto:wrcooke at wrcooke.net>
> To: cctalk at classiccmp.org <mailto:cctalk at classiccmp.org>
> Subject: Anyone heard of the S1 Operating System
> Reading through the April 85 issue of Byte, I came across a reference to the "S1 Operating System." In Jerry Pournelle's column on pg 361 he talks about this mysterious OS. Here is a small excerpt:
> Robert Knight. formerly of
> Princeton's computer laboratories. is
> an old fan of my books and columns
> as well as the creator of SI. which he
> had running on an IBM Instruments
> Anyway, my Googling turned up nothing on the OS, although I did find a Robert Knight at Princeton, but no information on stuff he's done. I will likely email him to ask about it, but wanted to ask here first if anyone knows anything about it.
I work at an astronomy facility. I get to do some fun dumpster diving.
I recently have pulled out of the trash a plugboard with a male and a
female D-Sub 52 connector. 3 rows of pins, 17-18-17. I took the
connectors off the board: there's nothing back there, so this thing only
ever existed so you could plug the random cable you found into it and its
friends to see what the cable fit.
I can't find much evidence that a 52-pin D-Sub ever existed.
Is this just Yet Another Physics Experiment thing where, hey, if your
instrument already costs three million dollars, what's a couple of grand
for machining custom connectors? Or was it once a thing?
(also posted to COFF)
?Thanks for all the replies to my original post.
I sold the heads separately along with a set of replacement cards and the remote display for $400.
>From It?s operational days I know one of my drum?s long channels (not a register) is bad. The coating ?looks? ok but it?s been exposed (indoors) for decades with ample touching etc but there are no dents or scratches other than the bad channel. As some have said it ?seems? like a durable coating but I have no idea if it would work. I read somewhere there are 2 timing tracks put down at the factory. I have my doubts about this info (I thought the timing circuit laid down the reference tracks in the final stage of power up) but if true I would not expect my drum to work. I have the drum connected to a small motor and belt to spin it (slowly) for demo purposes.
Anybody know what non-magnetic metal forms the drum? Stainless? Nickel?
> Does anyone have an idea as to the value of a Bendix G15 Drum? Its time to pass mine to another caring collector who would appreciate it but I am not sure how of its value. Obviously it is rare but the market demand is unclear to me.
ANyone interested in a kind of beat up but complete model 32, and you're in
cincinnati to get it today or this weekend let me know by sending me a
message through my web site
This is the fairest way, it takes the requests with a timestamp. I will
forward your info to the donor immediately, in order of receipt. He can
send photos if you need them. On a scale of one to 10 it's in "4-7"
condition depending on your taste. Has a built in phone and reader.
You must be able to physically go to this guy and pick it up this weekend.
(Just reposting this as it did not appear to appear on the list - there
was about a two week period when I didn't see any CCMP emails for some
reason - apologies if it has already appeared for others).
I apologize if this is OT but I'm hoping someone on the list can help me
fill a gap in my knowledge.
Quick back story - in 1995 my wife and I published a book on her family
history. For anyone interested in genealogy, details are here
I think we may have done the whole job end-to-end on a 486 before
sending a file to the book printers (we published 500 copies) but my
memory is vague on that point.
Of course the last job I did on the book I backed up the whole thing
(database files, image files, record and document scans etc) to a DC2120
tape. I've even found the tape:
The wife says that its time for an update to the book so that means drop
all other projects and see if you can get it back off the tape (with an
I know that I used a software app called ResQ120 to run the tape drive.
I can't find it (or any info) on-line other than the software came from
Alloy but I suspect I have it here somewhere on a floppy disk so its
only matter of time before I find that assuming the disk is still
readable. Of course over time I have acquired other tape drives from
various salvage/rescue sources but I believe this is the one I used:
What I'm missing is this - I recall that despite the PC having a floppy
controller I added a separate floppy (or similar or other) controller
(card) for the tape drive (it might have even run on the same interrupt
- I can't remember). As with most stuff, being a prolific rescuer I have
acquired many ISA based cards over the years that appear to be floppy
controllers but I have no idea what I'm looking for to run this tape
Any clues, info etc would greatly appreciated because I don't want to
have to tell her that it can't be done and you wouldn't want to be
around if she had to hear that :-)