jim stephens <jwsmail(a)jwsss.com> wrote:
> Sad day when AOL changed to CDs and you then had to make
> coasters or trash them.
My wife and our neighbor use them as reflectors to scare birds away from
her garden. We finally ran out of the AOL CDs and are now working on my
backlog of MSDN CDs. I keep them stacked on a 1/2" wooden dowel, and
still have a roughly 4' high stack. That should last us for a few years.
Alan Frisbie
On 9/1/22 18:43, Mike Katz wrote:
> Taking my memory back to the early 1980's and the Western Digital floppy
> disk controller chip family (177X single density and 179X double
> density). I wrote the 6809 drivers for Gimix Flex. The controller chip
> used the index pulse for sector zero position and for timing out a
> failed read or write command. I don't recall if that controller chip
> family could handle hard sectoring (one hole per sector) or not.
All WD and NEC floppy controllers use the index hole for formatting as
Fred mentioned. Further, I believe that three passes of the index hole
while attempting to read or write gets you "Sector not found" if the
address ID isn't detected. See datasheet and app notes for details.
No WD or NEC floppy controller handles hard-sectored recording schemes.
HOWEVER:
A few years back, I was sent a bunch of 8" HS disks that were really
puzzling--the sector ID address headers didn't line up with the sector
hole timing. In fact, they were WAY off.
It turns out that some 8" drives can be set to separate the sector holes
from the index hole (separate output pins for index and sector). Doing
so, gives you what amounts to a soft-sectored floppy, regardless of what
the physical object is. I know that I used a Siemens FDD-200 drive
jumpered accordingly to read them.
Good times.
--Chuck
Someone on Fesse Bouc just found a sealed box of SS/SD 8" floppies in
their garage.
Most FB types are too young to know 8" disks existed, of course.
Someone suggested punching a notch in them and using both sides.
Was that even possible on 8" disks?
(TBH single-sided actually-floppy floppies are before my time and I
never used 'em. When they were on low-end American 8-bit home
computers, this impecunious young Brit couldn't afford floppy drives
at all. By the time I could, 5.25" DS/DD was the cheapest drive and
cheapest media.)
--
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Thanks everyone for the interest. (Wish I had more.)
The lot has been spoken for. If it all falls through, I'll re-post.
Everyone, thanks again.
Dave
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I have the following PDP-8/a components.I do not know their operating
condition so they are being offered as is.I have had them for several
years, but I do not have the time to see if I can get a system running.I
would like to give them away as a lot and do not want to ship.I can send
photos on request.I live in Winterville, North Carolina (eastern part of
the state).Thanks, Dave
_PDP-8/a chassis with the following boards__:_ (a) Hex Omnibus CPU
M8315, (b) 8/A Internal Option MD317(?), (c) Option Board 1 M8316, (d)
Data Ram DR-118A 8Kx12, and (e) Core Memory Stack H-219A. Chassis has
the power supply.with G8018 regulator board.
_Loose parts and boards:_ DEC Console Panel 00KC8-AA, 2 DEC console
panels with limited function board, DEC H-219A, M8316 (has label that
says may be defective), Dataram DR-118A, and M8316/M340566.
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While cleaning up I found a box with 3 H7868 power supplies. Once upon a
time I had a BA213 and BA215 Vax.
One of them has a cable coming out the top of it and probably went to
the BA213 box which had only one power supply.
The other two are plain and likely are from a BA215 box.
I assume they are not working and if you want one or all I will ship if
you pay postage.
I am located in Zip 20640, shipping out of the US seems not worth the
trouble.
Doug
Here is a few systems that need to go.
Phase IV systems. comes in 3 Chassis Enclosures. lots of blinking lights and switches .these are a little odd, they have the video memory for the terminals on the computer itself.There are no disks, terminals or tape drivers. has not been turned on. Free to a good home.
Dec Writer II very good condition, very little yellowing. Works 300.00
Dec Writer III also in very good condition with very little Yellowing Works 300.00
HP 85 in original box, some manuals and tapes. Has a rom drawer with basic IO rom16 Meg Memory drawer. 2 Tapes, Visicalc and Standard Pac ?? Original manuals for
The 85 and Visicalc. Looks almost new with no fading. Box is Ok but wont handle
shipping. Has not been turned on in years. 500.00
Dec Application Dec 400XP Tower PC server. This is a Desk side PC Server with
Interactive Unix unlimited on it. Has 4 Dec SCSI drives. Tape Drive, Second SCSI cardand Satellite interface. Is missing the side Panel. Has not been run in a few years.
comes with a spare drives and some boards. Intel 486 DX 50. 100.00
HP 9000 380 System. This was a donation from HP to a local College. Comes in 4 Desk
side Chassis. 2 hold Large Hard drives. There is a SCSI Disk enclosure with drives. This was most likely the best they had in the day. Was holding what looked like a complete
working HPUX system. Email, Gofer where all intact. . Condition is very good. Has not been
turned on in a few years. Was backed up to 4mm tape at one point. 1000.00
Motorola Development system. 68k Was told it was a complete system. comes in 2 large boxes. Don't know much about this, does have Pods and a large Computer type interfaceHas not been turned on. 100.00
HP 7070E Tape drive. still loads a tape, but has not been tested further. Good conditionThis is a large floor standing tape drive with HPIB interface. 300.00
I also have a large Tandy/Radio Shack Collection that needs thinning. Most models. Alongwith 14 Kaypros Most models.
These are located in Kent, Washington. No Shipping unless you want to arrange it. I canhaul it locally .
- Jerryg-wright(a)att.net
I have a nice HP1630G logic analyser. It still works OK but has a number of
issues that I would like to fix.
First, I managed to break the power switch. It became stiff and wouldn't
readily toggle the power. I think the shaft became bent. In pressing too
hard, I broke off the button on the end of the shaft. Looking at it, I think
the button may have been glued onto the end of the shaft, possibly in a
previous repair. There are some sites that list the button as available so I
am trying to source an original, but I think it could be just the button and
not the shaft that goes with it. However, if that proves impractical or too
expensive, I am wondering if it is possible to source a new switch, with a
long shaft to reach the switch on the board, that would at least allow me to
toggle power from the front panel? I am not sure what to search for though,
any suggestions? I have several possible workarounds: 1) just leave the
switch on permanently and "toggle" the power just by plugging into the mains
2) try to glue the button back on, possibly with a metal pin for strength,
but I think there is a bend in the shaft that caused the action not to work
well and so this may not work well 3) Raid a spare from a HP1630D that I
also have. 4) try to make a new shaft and switch, possibly 3D printed, or
just use a piece of wooden dowelling. Any comments on these approaches?
The other problem I have is that I get terrible switch bounce from the front
panel keyboard. I have removed the keyboard to see if I can get at the
switches and see if cleaning them would help. However, the keys (made by
Cherry) look like sealed units to me. Again, does anyone have any advice on
how to improve the performance of these switches? I could again raid my
HP1630D for a spare (which has a keyboard that isn't as bad), but would
rather not have to do so.
Finally, I get a bit of screen wobble on the display. I am going to check
all the capacitors on the display board, but any other suggestions?
Pictures of the broken switch and the keyboard are here:
https://1drv.ms/u/s!AgETuZFainX8gZNMqek10fyE3n1rlw?e=xd7RWU
Regards
Rob
So I'm working on repairing a TU58 Dectape II drive. So far I have
cleaned it up, replaced the rollers, put new bands in some TU58 carts,
and have fixed the power supply so +5 and +12 are up and running.
Turning on the unit with nothing in it results in a quick flash of light
from the LED on the main board. Hooking it up to an 11/23+ and trying to
boot off it gives me ERR 12 NON-EXISTENT CONTROLLER
Drat.
It's connected to the 11/23+ with a normal 10 pin ribbon cable with keys
at both ends. So questions:
Baud rates are wired in at 9600/9600 on both the unit and the CPU.
1) Is the quick flash on the inside LED normal when powered up
2) Does it require something more than a simple ribbon cable to connect
to the CPU?
3) Should the unit do something else with a tape in and powered on?
Thanks!
Chris
