In addition to everything already cited, he developed what is still my
favorite dithering algorithm. Atkinson dither was probably optimized
more for speed than anything, but I've always loved the look of it, and
have even implemented it myself for that reason. R.I.P., sir.
Tadpole were in Cambridge, weren't they ?
https://www.computinghistory.org.uk/ have collected a fair bit of
Cambridge history. I haven't found them very willing to search their
archives but there may be individuals who have more time available, or
they may have a resource problem in putting information online.
On Fri, Jun 6, 2025 at 8:28 AM erik--- via cctalk <cctalk(a)classiccmp.org> wrote:
>
>
>
> Hi Andreas,
>
> great that there are still some people looking into the
> old SPARCbooks from Tadpole. I have got a 3GX up and running.
>
> > Sadly there seems to be almost no documentation available
> > in the net for a Sparcbook 2
>
> Yeah, that is really sad. Also do not have got any information!
> Just to report from my work on the 3 series ones (which are
> probably not to different from the earlier ones):
>
> Mine works without battery pack, so there is some intelligence
> in the battery pack (for power management), but using a power
> supply it is working even without that pack!
>
> > - after trying to reboot the unit will be almost dead.
> > While pressing the power on button the LEDs on the left
> > upper side of the display will
> > be lit shortly, but nothing else will happen.
>
> Hmm, that sounds strange and I never observed this due to
> lost NVram values. But what I observed is the yellow/orange
> Tantalum caps going bad in the small power supply piggy back
> PCB inside the unit. A short prevents the notebook from
> working (and sometimes even some inductors release smoke and
> completely destroyong the PCB depending on which cap went
> short).
> After a longer time powered off, the faulty cap can recover
> explaining your observation. Fortunately I had some spare
> PCBs and replaced all caps in my live one which works nicely
> now...
>
> Good luck,
>
> Erik.
>
I was given an ASR-33 complete with stand, read & punch.
This ASR-33 has been modified for RS-232 though a blue perfboard mounted
in the connection enclosure (under the cover place where the dialer
would be.
Is has a DB25 ribbon cable coming off of this board. The perfboard does
not have a label on it that I can find.
The ASR-33 also has a 3 x 5 conductor rectangular connector coming out
of the read of the unit with 6 female contacts installed.
I was able to connect the ARS-33 to a VT-330+ at 110B 8-N-2 and send and
receive on the teletype.
The punch seems to work as well.
The reader will "chatter" then the reader is put in the stop position
and the tape out sensor is pressed but the sprocket does not advance and
the reader pins to not move.
Questions:
1. Why the reader is not advancing and the pins are not activating?
Could this be a read enable contact not being in the active position?
2. What are the outs of the RS-232 DB-25. Other than TX, RX and GND
3. What are the pin outs of the 3 x 5 rectangular connector. I think
this is the current loop and other control signals.
Does any any of the items below for sale or have a 3D model I can print:
1. Roll Paper spindle (the spindle that the roll paper spins on)
2. Paper Tape Punch Spindle (the spindle that the paper tape spins on)
3. Paper Tape Chad feed tube
4. Paper Tape Chad Box
I will be connecting this to either a PiDP-8/I or a PDP-8/E for now and
eventually a PDP-8/L
Thank you,
Mike
Hi Andreas,
great that there are still some people looking into the
old SPARCbooks from Tadpole. I have got a 3GX up and running.
> Sadly there seems to be almost no documentation available
> in the net for a Sparcbook 2
Yeah, that is really sad. Also do not have got any information!
Just to report from my work on the 3 series ones (which are
probably not to different from the earlier ones):
Mine works without battery pack, so there is some intelligence
in the battery pack (for power management), but using a power
supply it is working even without that pack!
> - after trying to reboot the unit will be almost dead.
> While pressing the power on button the LEDs on the left
> upper side of the display will
> be lit shortly, but nothing else will happen.
Hmm, that sounds strange and I never observed this due to
lost NVram values. But what I observed is the yellow/orange
Tantalum caps going bad in the small power supply piggy back
PCB inside the unit. A short prevents the notebook from
working (and sometimes even some inductors release smoke and
completely destroyong the PCB depending on which cap went
short).
After a longer time powered off, the faulty cap can recover
explaining your observation. Fortunately I had some spare
PCBs and replaced all caps in my live one which works nicely
now...
Good luck,
Erik.
Swap Meet Update 6/5/25
So the negotiations with the weather gods have been successful!
The latest weather forecast shows a 57% chance of rain around 8AM and
thunderstorms 5PM or later.
So with this, I'm going ahead with the swap meet as planned.
Everyone is encouraged to use their best judgment as to their safety in
coming to the event.
My highest recommendation is to bring a tent that can be anchored with
sandbags. Generally a good idea regardless of rain.
Also bring waterproof clothing (i.e. raincoats, etc.)
If any vendor should feel uncomfortable and needs to cancel, we will refund
you, but once you show up, there is no refund.
Vendor setup is 7AM
General Admission is 8AM
More info here: https://vcfed.org/vcf-swap-meet/
There is a copy of the Convergent CTOS EDL (ethernet data link / packet driver) for the ETH150 (SMC 8416T ISA ethernet) board on Bitsavers.
I am wanting to make use of an SG410P (CTOS EISA Ethernet IOP) but as far as I can tell the EDL archived on Bitsavers is missing the piece(s) necessary for use with an IOP or other supported non-ISA ethernet board.
Has another copy of the EDL survived? Can it be made available? It might be the case that it was included as a separate disk in another CTOS networking software package (e.g. TCP/IP, OSI Transport, or LANce).
Secondarily, CTOS FTP has ISAM II as a pre-req; Bitsavers has (what appears to be) an update-only disk archived, but no “base” install. I’d be quite interested in finding out if that has survived and could be made available as well.
If there’s a more likely mailing list or forum I might also direct my enquiries, I’ll be glad to engage there. Thanks!
ok
bear.
Does anyone here have or know of ComputerVision CADDStation input devices (e.g., puck, tablet) that ard for sale? I have started restoring the CADDStation Model 32 that has been sitting in my garage for a while but am missing some pieces to get the full experience.
alan
Hello all,
I have transferred some simh .tap files to my PDP-11/23+ running RSX11M+.
There I have tried to use VCP to attach them to a virtual device but I keep
getting an invalid record format error. I then realized the simh .tap files
most likely aren't organized correctly. If I attach them to TS0 in simh I
can work with them. So now I am trying duplicate a tape into a new .tap
file created using VCP. I can't for the life of me get it to work though.
BRU doesn't support tape-to-tape and FLX doesn't complain but also never
completes. Is there a process for tape duplication under RSX?
The images were first transferred to my PiDP-11 using ftp in binary mode
over TCP/IP. From there I used NFT in image mode and I tried both record
and block modes.
I have also seen the simh tape tools but there doesn't seem to be a tool to
convert a simh file back to what would be on a real tape.
Anyone have any information or pointers to get this to work?
Thanks!
-Peter
