@Jonathan: Wow, amazing project in creating the replacement NVRAM. You really
spent lot of time and efforts into that one. To attach the external battery I
took a X-Ray to know where to have access to the battery pins most easily - was
just 1 hour of work but far less cool of course! Thanks
I bought this giant GCR tape drive on eBay five years ago,
http://www.bitsavers.org/pdf/fujitsu/_brochures/M244X_Brochure_1984.pdf
hoping to be able to use it to extract analog signals from 6250 BPI
tapes to feed into my decoding program.
https://github.com/LenShustek/readtape
I failed to
The DEC H7441 regulator is a relatively complex circuit using 2 x 555
timers, 2 x LM301 op-amps, 2 x transformers and 2 inductors
I am struggling to understand how it is meant to work and was hoping to
find a maintenance manual for it.
Could anyone with such a manual please help?
Alternatively
Thanks Jonathan.
I'm not sure this is correct as I needed to select a DS1643 after I tied
pin 26 and pin 27 to pin 28 (and cut 26 and 27 in a chip socket/adapter)
but I did manage to dump it. It is very small though. All zeros until
data starts at 0x1800.
Would you have an idea if this is
> On Sep 27, 2023, at 12:25 PM, Jay Jaeger via cctalk
> wrote:
>
> I have some open slots in some of my racks. I do have some old DEC rails,
> but I have a fair amount of equipment, from both DEC and other manufacturers,
> for which those rails are not suitable.
>
> Does anyone have any
> Hi Jonathan, thanks for your thoughs. I am still using the same NVRAM, just
> with external battery attached, so no Chineese counterfeit.
> My hypothesis is: With the battery losing voltage, some bits flip first. They
> cause the error message you see and values get set to proper values. But
> Interesting - did you youse some modern technology for
> doing that?
Modern "special sauce" replacements from Dallas/Maxim/Analog/etc., plus a fast,
low-power SRAM, all packaged on a circuit board with Batten & Allen DIP
leadframe pins, like this:
> Speaking of dumping...
>
> Is it possible to read a Dallas DS1643 in programmer? That's what's in my
> Ultrabook. I just tried with a Topmax II that supports it and I get all
> zeros. :(
You probably need to make a shim socket and pull pin 26 to VCC (pin 28), then
read it as a DS1225. I'd
Speaking of dumping...
Is it possible to read a Dallas DS1643 in programmer? That's what's in my
Ultrabook. I just tried with a Topmax II that supports it and I get all
zeros. :(
Santo
On Wed, Sep 27, 2023 at 4:14 PM Ethan O'Toole via cctalk <
cctalk@classiccmp.org> wrote:
> > Interesting
Hi Ethan - yes, I think that may be a severe issue and getting hands on a
dump/making users aware was already in my first post and therefore it is also
titled "species needs rescue" ;-)
Never looked into MAME - if they run the OpenBoot firmware, that would indeed
be an opion! Thanks for the
Interesting - did you youse some modern technology for
doing that? I already thought to attach a logic analyzer to the
NVRAM to see which bytes are read first (e.g. for dtermining
the hardware configuration).
Late to the convo, but it's interesting.
You might be able to dump the ROMs and find
Hi Jonathan!
> Now the good news is, I can probably make replacements
> for the DS1553W. I already have a prototype replacement
> for the DS1643
Interesting - did you youse some modern technology for
doing that? I already thought to attach a logic analyzer to the
NVRAM to see which bytes are
Hi Jonathan, thanks for your thoughs. I am still using the same NVRAM, just
with external battery attached, so no Chineese counterfeit.
My hypothesis is: With the battery losing voltage, some bits flip first. They
cause the error message you see and values get set to proper values. But there
Hi Santo, thanks for your efforts in taking the vid that looks different from
my behaviour on all UltraBooks!
Drive Caddy: They are silly devices - no smart stuff. I can take pictures on
the weekend and make a wiring chart if you want.
I have a 160GB drive, WD1600BEVE for the OS. Erik.
I have some open slots in some of my racks. I do have some old DEC
rails, but I have a fair amount of equipment, from both DEC and other
manufacturers, for which those rails are not suitable.
Does anyone have any specific recommendations for shelving? (where
equipment could just be slid on
I'm a bit late to the ballgame, but I use Depot 4 - which is available for
download from Curious Marc.
https://www.curiousmarc.com/computing/overland-tape-drive
On Wed, Sep 27, 2023 at 1:00 PM Anders Nelson via cctalk <
cctalk@classiccmp.org> wrote:
> Yup, right there in /doc.
> --
> Anders
/me hears mention of dead NVRAMs and materializes
Pulled out my UltraBook IIe today, it's fine with a dead NVRAM, just gives you
the usual "IDPROM contents are invalid" message you see on Suns.
If I'd have to guess, based on past experience, you likely have a counterfeit
DS1553W or you ordered
Yup, right there in /doc.
--
Anders Nelson
www.andersknelson.com
On Wed, Sep 27, 2023 at 2:58 PM Anders Nelson
wrote:
> Chuck - is this the one?:
>
> https://github.com/Tubatstuff/Pertec-Interface-Tape-Controller
>
> =]
> --
> Anders Nelson
> www.andersknelson.com
>
>
> On Tue, Sep 26, 2023 at
Hi Erik,
I just happen to have mine out and took a quick video of boot up. Mine
does not have a floppy drive or hard drive (I don't have a caddy) so it
boots pretty quickly to the "ok" prompt but you can see the LCD display and
when the LCD comes up.
Here's a quick video.
Chuck - is this the one?:
https://github.com/Tubatstuff/Pertec-Interface-Tape-Controller
=]
--
Anders Nelson
www.andersknelson.com
On Tue, Sep 26, 2023 at 11:13 AM Chuck Guzis via cctalk <
cctalk@classiccmp.org> wrote:
> On 9/26/23 07:11, jim stephens via cctalk wrote:
> > Overland data
Did some experiments in removing/swapping NVRAMs and none of my UltraBooks is
reaching the OpenFirmware or even turning on the backlight/LCD, so I have no
way of trying to read the NVRAM contents from there :-(
Symptoms (i.e. behaviour of the LCD display) of the UltraBooks differ with
contents
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