I have three DEC RA8x drives that have failed (all of them fault with
"spin error") because of bad photo-interrupter tachometer sensors. After
talking to a few friends, it sounds like this is a pretty common fault.
Photo sensors like this are fairly common, even today, but the specific
parts DEC used are weird and unobtainable.
I designed a little PC board that uses an ITR9606 photo interrupter, a
2N3904 and a resistor as a replacement. Works great - gives a beautiful 5V
P-P clean waveform and with the PCB it's a mechanical drop in replacement.
Just screws right onto the original mounting holes and plugs into the
original connector.
I put the PCB design up on OSH Park
https://oshpark.com/shared_projects/z8DSkQsP
If anybody needs one you're welcome to order some PCBs and build your own.
The ITR9606 is as common as dirt, and you can buy bags of ten on Amazon for
a few bucks.
I've also put a few pictures on the Facebook DEC Computer Users group. I'd
post the pictures here, but I don't think cctalk accepts attachments. It's
not really worth making a web page for it.
Bob
Got the Peanuts out today for a shakedown. They work well, or at least they did
until about 5 minutes into playing Kings Quest when the h-sync on the monitor
suddenly went out. Colours show and match what should be on screen but the
horizontal display is scrambled. It does it on both Peanuts, so I think
something in the display blew.
Anyone recognize this issue? Seems like it should be a straightforward fix; I
can't imagine this monitor is particularly complex internally.
--
------------------------------------ personal: http://www.cameronkaiser.com/ --
Cameron Kaiser * Floodgap Systems * www.floodgap.com * ckaiser(a)floodgap.com
-- Put down your guns, it's Weasel Stomping Day! ------------------------------
So, I screwed up and in my excitement to find a DEC BA123 chassis (and MVII parts) I bid on an Ebay auction where there is no shipping and it's "Local Pickup Only". The problem is that I'm near Fort Worth TX and the MVII/BA123 is in Brunswick, GA and I don't really have the time to make the 2000+ mile round trip drive to pick it up.
Does anyone here know of a reliable shipping service in Brunswick, GA? Or suggestions for outfits to check out? Google hasn't shown me much other that UPS and FedEx stores.
Failing that, is there anyone near enough willing to pick it up in Brunswick that might want it for themselves?
Ebay listing https://www.ebay.com/itm/334615827742?
--
John H. Reinhardt
> From: pbirkel(a)gmail.com
> Sent: Sunday, November 6, 2022 2:50 AM
> To: General Discussion: On-Topic and Off-Topic Posts
<cctalk(a)classiccmp.org>
> Subject: Seeking DEC BN25B-nn Optical Fiber Cable
>
> This is a twin/duplex cable of varying length with 100/140 um "multimode"
cores and
> SMA-906 connectors. SMA-906 connectors have the stepped center-pin,
compared to
> the SMA-905 which is a simpler straight pin. It's used, for example, by
the LAN Bridge 100.
>
> For additional information see pages 169 through 335 (of 452) in
>
http://www.bitsavers.org/pdf/dec/comm/EK-CMIV7-RM-005_Communications_Options
_Minireference_Manual_Vol7_Aug88.pdf
I'm reliably informed that the cable actually has a light beige jacket (not
orange), so not so easy to spot in your tangled pile of cables :-{.
paul
Hi folks!
Is there anyone out there, who can help me with my Beehive Topper
CP/M machine?
The machine starts up with his self-test going o.k.
Then it requests for the boot disk or pressing RETURN to start
the Monitor V2.0 program.
The Monitor program seems to work o.k.
Booting a disk (written from the images out of the Maslin archive)
puts some cryptic characters of the screen and hangs the machine.
The images are for a Topper II, mine is a model Topper.
Is this the problem?
I have found very very little about the Topper machines,
no manuals, no software, no schematics.
R. Harten
--
Liam,
i'm sorry, but Chuck is right.
Your link directs to a photo showing a terminal.
The Topper was put into market as a intelligent terminal for
stand alone use as a CP/M machine and for remote issues as a
IBM compatible terminal.
In fact the Topper has a 8085 CPU for the terminal part and a Z80
for the CP/M part.
On booting the system disk you should be asked which functionalilty
you want.
There is a marketing brochure i have found in the www, where the
Topper is mentioned beside some other Beehive terminals.
Rolf
This is a twin/duplex cable of varying length with 100/140 um "multimode"
cores and SMA-906 connectors. SMA-906 connectors have the stepped
center-pin, compared to the SMA-905 which is a simpler straight pin. It's
used, for example, by the LAN Bridge 100.
For additional information see pages 169 through 335 (of 452) in
http://www.bitsavers.org/pdf/dec/comm/EK-CMIV7-RM-005_Communications_Options
_Minireference_Manual_Vol7_Aug88.pdf
Probably it has an orange sheath so it would be somewhat distinctive in your
tangled pile of cables :-}.
Thank you for looking,
paul
I attended Queen Mary College from 86-89. They had just received several
dozen MG1s. I believe the WCW founders came from QMC.
By the final year a good 1/4 we're non-functional as the keyboards has
failed and by then WCW has gone bankrupt a second time (for good). I
remember one the programmers trying to encourage the more enterprising 3rd
year students to take on building a IBM keyboard adapter as their final
year project :-)
I'd love one for nostalgias sake but I live in the US now though shipping
to my mum's may be possible though no clue if they can handle 120v.
Lots of good memories. Eliot Miranda worked at QMC and had ported his
BrouHaHa smalltalk to the MG1. I remember using Occam (emulator), Lisp,
ML, Modula2 and C plus of course Smalltalk 80 all on the MG1.
Tony
Hi everyone!
I'm curious; other than Wikipedia what do we know about Whitechapel
workstations? Do any of us have some working in our collections, with
software, disk dumps, etc?
Cheers!
Hi,
n00b alert
Does anyone have a 101 level boot strap guide for someone wanting to get
into creating better-than-dd disk images?
I'm finding myself back in a position where I want to image / preserve
multiple 5¼ & 3½ inch disks. I think all of them are PC compatible
disks. Probably standard FAT-12 and a handful of super capacity disk
formats from the likes of IBM / Microsoft where they tried to squeeze
1.6 (?) MB on a 3½ inch disk.
I have an internal 5¼ inch floppy drive that is in unknown condition
(I've never used / tested it since I got it).
I also have (at least one) 5¼ disk that I acquired as a scratch monkey
disk to test on before working on disks that I care more about.
I was thinking about acquiring a Kryoflux in the next few months and
starting to collect better quality images of disks. I recently saw
someone on Twitter suggest that Kryoflux wasn't the best route to go and
suggested a SuperCard Pro instead.
I had been using the dd command under Linux against a USB connected 3½
inch floppy drive for most things. But I've come to learn that's not as
good as some people would like to see preserved.
So, does anyone have a 101 level boot strap guide for someone wanting to
get into creating better-than-dd disk images?
--
Grant. . . .
unix || die
