Is there a schematic for the H7441 regulator anywhere? There are several
out there for the H744 but, although they are plug compatible, the H7441 is
totally different. The H744 uses an LM723, but in the 7441 DEC appears to
have rolled their own regulator using a bunch discrete parts and opamps.
Bob
We use groups,io for the tom swift discussion group real handy to post photos, files and etc..
On Wednesday, June 17, 2020 Chris Hanson via cctalk <cmhanson at eschatologist.net; cctalk at classiccmp.org> wrote:
On Jun 17, 2020, at 1:50 AM, Tor Arntsen via cctalk <cctalk at classiccmp.org> wrote:
>
>>>> There is also groups.io, and it has some very nice features compared to
>
> Please please, no groups of any kinds. They're all horrible to use.
Do you mean "web forum" where you say "groups?"
> A
> genuine mailing list like this is infinitively easier to keep track of
> and read at leisure. Can't stand groups.io.
I've found the groups.io <http://groups.io/> mailing list mode to be perfectly reasonable for a number of groups I'm a part of. And it has a forum-like front end for people who insist on doing everything through a web page.
? -- Chris
Guys,
I have acquired this board and have trouble assigning it to a particular
computer manufacturer and type:
https://lh3.googleusercontent.com/byRPH3wCR2aqxGX9U8BZfFTT_XtF7QCKSyVXoNmGIk
UheiJ5BWqxYaCWdEshppLGYkOqUD7fl9XNeVzO_tDRKVOtbC3Js7T-pOvNUHs9MY9A36fc7dU6ro
1i7hx9Uhcfc6ukEGIdC5Ac6aTQhEFFoeWBxiI6Z24hZdvq1r6vRb4o-Lj778Wbo15hwxu0JxMuxE
tcopNv0FG0_g6nUv0Eofalqu4TmgPfUWVCd4Y4LdA0pnhDRMYF5c2ASzS00TsyukCVrUyr298tjo
vztVzUGEPHNL1beVCriuQIBLITaEMX3N8EBDuxpfav0vHFuyy9yfAgUI4uJB9qT6aFGEk2KplIVt
yNWZf9phTdj-jLtqns9WvdA9Ur2klrk4uPzMyWg6SKTKRlpMrvbJuMnqZodzxPFPvWCG5--kVVBD
KRAXW8xOTOPyxXx0xrcPifO49ni2SFYIkZgTb9d4gzvJaM8ugEb-jqHlc7uqHz5glwe4PfoN838w
zMozr43veZSNHRTm9IMfON-w7xvbVufJpa_MzhuaTlKf9pvVcRIuxfhG4pMeVq7K6phhHpsKPfG5
h4BRgDSimCE8mToI35IWS3Ty8j01-6bibKH_kB-t35aIdkv7JIC-YZ1sDoguSdyk8h1xbM2d9i_U
LFQYVC0oCHESgEGdqzGO3ntgwmV4khjgaQkcp2Bk-TuC7Nwrl57JI=w654-h871-no?authuser=
0
https://lh3.googleusercontent.com/HvltevPwIvyJF0qiAJR6wCAkI4lHfFGL2Gos5uoT4a
qEJNFBAwJ3m6XX8E6k0m515EYgZJMaCwFGXiGiTCkxDeT396EjsbkukK3_XYqNDjfU8o3Pbtdq8z
vm_q7MXShANXVFUL2wjXEbAhvBug1h42tZnxpDaxTCeNIHjqF2bgs6J_S3wCjmx538E4AuHCHxrr
CqIr8yvL7AGlZXCWe8u05YNNZbIrUCYHbTtxh15hc0SwfRPzQ2U2v-pPxHs7-rx5mPpwxovbp24a
CdwLBf5RRvvEZWZgyDGKG8xdF-al4kQdZMgxrVVXFMse3ee_J-QaYgALUxckGeWp2QxM4wolrd8Q
Y1PqaMaTgbws5WSrOeBBBZrhmrUeL4TzZAlCA4-FqtRpoPIA339y9JRixB8Q6LlUeNsWzlqGqkvC
JSCHlh_hpCXgwemhOtF4B1CLvNGs-PSZjTsnj_KOeSgeINz5Sc6TCrHmnxCcIY6D42aKMJRHZ9I9
7Z02FLsKwN6IKLxjifZvrkmEX4L8qXLbd8cuF0uf1PMjwC9WNC1_QpOmMiJOrBloG9pdrHRGvmfR
RPQE7c6_HxVklEpIbxqkLmQVkKF-oM8VYS3A11tvslxiZUcvQcEhuEYhPLoqTD8PDikYhxKyVLhq
S0DC-bIVBDDLeqiegQelHFjhptKwgs-0Q5mMrxvE6rdsd6-ipEf5Q=w654-h871-no?authuser=
0
Smells of (early) 1960s transistorized.
No helpful marking apart from
* "GATE JJ01" on SIDE A. (components).
* "C NT OL DATA" on side B (solder traces).
Big transistors are Motorola "180376008". Also, any ideas what the "246 636
B" boxes are, they have four legs?
Can any of you of mature years suggest anything?
Many thanks,
peter
|| | | | | | | | |
Peter Van Peborgh
62 St Mary's Rise
Writhlington Radstock
Somerset BA3 3PD
UK
01761 439 234
"Our times are in God's wise and loving hands"
|| | | | | | | | |
Not exactly on subject, but problems designing the IBM 604 Electronic Calculating Punch due to the use of existing vacuum tube designs is discussed in section 2.4 of:
Charles J. Bashe, Lyle R. Johnson, John H. Palmer, and Emerson W. Pugh
IBM?s Early Computers
The MIT Press, 1986
The book says Ralph Palmer set up a vacuum tube laboratory with the ability to manufacture small quantities of tubes. This helped them get credibility when they went to a vacuum tube manufacturer with a request for a design change to achieve the needed reliability for digital applications.
Hi!
Anyone else getting duplicate messages from this list? I get 2 copies of
most (but not all) messages, with the second copy often arriving
significantly later.
Julf
Hi all.
I recently bought a mystery blinkenlight panel. Closer inspection reveals it was manufactured by Intel in the early 70?s (1973), and some people on the book of faces suggested it was part of a ?device multiplexer?(?)
I?m 95% confident it?s not strictly a ?computer? blinkenlight panel, but rather an attached device, but that still hasn?t helped me narrow down what exactly it was from.
I?ve not seen any early Intel stuff as rack-mount, so i?m wondering if it was a prototype, or maybe a piece of internal/non-commercial hardware for Intel's own use.
I?m hoping someone here might be able to shed some light on this mystery.
Pictures: https://imgur.com/gallery/lD74oSy <https://imgur.com/gallery/lD74oSy>
Thanks in advance.
Josh Rice
Is there anyone that has already built a tool to dump TU58-tapes on a Linux
machine? I have the drive of course.
There is PUTR. But it is DOS only and is written in assembler so it cannot
be ported easily. The other option is running RT11 on a PDP-11, but then
there is the hassle of getting the dumps off the RT11 file system.
It is probably not too difficult to use relevant parts of the various TU58
Unix implementations out there to do something quickly, but if someone has
already done it, it would be great to not reinvent the wheel.
I have approximately 80 11/730 and 11/750 console and diag tapes that
need reading.
/Mattis
Folks,
I think I now have too many 3174 controllers. I have
1 x Rack Mount - Token Ring Card + MFM Disk Emulator
1 x Large Tabletop - Token Card
1 x Large Tabletop - Ethernet Card <=> I am keeping this.
1 x Small Tabletop - Token Ring card but won't run TCPIP code.
If anyone wants one of these I am happy to ship at cost but they are
220/240v and heavy so shipping to USA may be a problem.
I have a selection of floppy drives that can be fitted but I recommend using
a Gotek with FlashFloppy firmware.
I also have the following spares:-
1. working PSU for rack mount
2. non-working PSU for the rackmount systems but I am sure it can be
fixed
3. spare motherboard for rackmount
4. spare token ring card (if I can find it)
5. (I may have memory modules but can't remember where I put them
6. I think I have a 3299 multiplexor some where
Feel free to e-mail off-list with questions.
Dave Wade
G4UGM & EA7KAE
> With Jay retiring, what are the hosting plans for these mailing lists?
Hi Al,
I didn't know about Jay retiring or what that means for the list - i.e. does it need to find new infrastructure, new administraton/management, or both? I'm a relatively background person in the vintage computing scheme of things but I do have an involvement in the data centre / hosting area & so if no better options were to come forward would be very happy to pitch in somehow.
Don't know if anybody much cares, but:
The HDL synthesis aspect of the SMS data gathering / HDL synthesis
application is coming along. I can now handle:
- Oscillators (using a counter divider)
- Delay lines (using a shift register, so limited to a reasonable number
of FPGA clock clock cycles, so, say 200 ns is not unreasonable (20 bit
shift register at 100 MHz).
- Recognition and consolidation of individual signals into a "bus" when
generating groups corresponding to a group of individual ALD sheets.
(The individual ALD sheets use the individual signal names as they
appear on the sheet). A simple database table associates a given
individual signal with a bus, and identifies the bit in the bus that
corresponds to the individual signal.
So, I have not generated the IBM 1410 main oscillator, its main logic
clock and its I Ring - used to control instruction decode. I have
synthesized the logic clock into an FPGA and run it (with a slowed down
1410 oscillator so I could see what was going on.)
Also, a word about VHDL - and the Xilinx Vivado. While GHDL is useful,
I have found that Vivado is not slow at editing and *simulation*. Silly
me - I got in the habit of synthesizing stuff before I tested it under
simulation - partly because I didn't know any better at first. Vivado's
waveform viewer has some advantages (and disadvantages) compared to what
is available for GHDL.
I have also started exploring a piece of "intellectual property" I can
use - MicroBlaze - to allow my generated system to talk to my PC, via
TCP, for things like lights and switches. (Kind of like how the Amdahl
machines used to use first DG Novas, and later little UNIX systems for
their consoles, giving them access to the internals of the machine.)
I knew MicroBlaze existed, but now I have actually played with it a bit
-- still learning.
https://en.wikipedia.org/wiki/MicroBlaze
OK. the keyboard is working properly as far as I can tell, data is going
in and out, and I even swapped it for the keyboard on my VT220 and the
same symptoms persisted.
I just verified all four ROMs on the T11, and the ROM for the 8085,
against the images I found on the MAME site. So far so good.
One interesting finding - two of the lines (DAL3 and DAL1) on the T11 do
change states several times, but once the self-test has crashed, they
stay high with almost one volt of "wiggle". All the other data/address
lines are either high, low or switching between a good 1 and 0.
There are several places that the bus connects, including the ROMs,
1-bit dynamic RAMs and various octal latches & bidirectional buffers. I
connected a 10 ma VOM between each line and ground (to make sure a
low-resistance path (such as in the 'LS245 at E55) wasn't forcing it
high somehow.
All of the DAL15-0 lines requires more than 1.9 ma to bring it to ground
(well, 50 mv burden at 250 mv full scale, anyway).
That leaves the unlikely possibility that one of the octal TTL devices,
or ROMs. has developed a weird internal pathway that only interferes
with DAL3 & 1 on some bit patterns, but not all the time. Seems like a
zebra rather than a horse. The only part that drives multiple low-order
DAL lines at once besides the E19-22 ROMs is the E55 LS245.
The T11 spec sheet says that a good logic 0 (<0.4 volt) should be
possible with up to 3.2 ma sink... So I suspect the T11 has a couple of
bad output pull-down transistors on those lines. Anyone got a spare T11
chip I can buy or borrow? Or send you mine to plug into your board and
see if it fails the same way? :)
thanks.
Add on? solid state memory unit? some semi companies made tjem. For add to Dec and dg?? Dunno. A guess
....?? ed smecc
On Sunday, June 14, 2020 Joshua Rice via cctalk <Rice43 at btinternet.com; cctalk at classiccmp.org> wrote:
Hi all.
I recently bought a mystery blinkenlight panel. Closer inspection reveals it was manufactured by Intel in the early 70?s (1973), and some people on the book of faces suggested it was part of a ?device multiplexer?(?)
I?m 95% confident it?s not strictly a ?computer? blinkenlight panel, but rather an attached device, but that still hasn?t helped me narrow down what exactly it was from.
I?ve not seen any early Intel stuff as rack-mount, so i?m wondering if it was a prototype, or maybe a piece of internal/non-commercial hardware for Intel's own use.
I?m hoping someone here might be able to shed some light on this mystery.
Pictures: https://imgur.com/gallery/lD74oSy <https://imgur.com/gallery/lD74oSy>
Thanks in advance.
Josh Rice
I am getting closer to retirement (although not close enough) and I'm
considering selling off my PDP stuff, especially if I downsize and move.
Everything's working, but I just no longer DO anything with either
system... the adventure was acquiring all the pieces, fixing them and
learning the software :)
Anyhow I have an 8/A with cloned Programmer's Panel (Vince Slyngstad and
I made it around 2006) and limited function panel, 32K RAM board (also
have core), Philipp Hachtmann's USB interface board, RX01 floppy, two
RL02's, and a high-speed (optical) reel-to-reel paper tape reader. OS/8
is up and running. Several spare RL02 packs. It's all in a tall DEC rack
with an H-(something) power control box. The ASR-33 is not included, I'm
keeping that.
Also an 11/23+ (11/03 chassis) in a corporate cabinet with two RL02's, a
16-line serial interface, VT-220 terminal. Also an RQDX3 which is
connected to a loose 3.5" TEAC floppy drive. Have RT-11XM, RT-11SJ and
TSX-Plus 6.50 (all 16 timesharing ports are working too).
So, I am wondering if there's any market for them (preferably as
complete systems). Shipping would be difficult due to the size/weight
(I'm in rural south central Missouri). I'm not looking to give them
away, or to part out, but would entertain reasonable package deals
rather than deal with the "LQQK! RARE!!" bull on ebay.
I can send pics to interested parties. Let me know,
thanks!
Charles
I have a bunch of Power7 720's I would like to get running, and I'm have a
tough time tracking down any VIOS newer than 2.1. Does someone here have
some 2.2.6 or later CD's they would like to sell me?
Thanks!
--
Hi all --
I'm working on a PDP-8/A I picked up at VCF West last summer. After a lot
of cleaning and some power supply repair it's showing signs of life (CPU
seems to be at least minimally functional, core memory is going to need
some debugging.)
The transformer in the power supply is humming quite loudly, however, and
I'm curious if this is normal for the 8/A (or is typical for an 8/A of this
vintage). I'm used to the supplies in various other DEC machines not being
exactly silent but this is a rather severe 60Hz buzz that you can clearly
hear over the fans when the machine is in operation.
Thanks,
Josh
Hello,
I'm looking for Cobalt Qube cases, preferably in North America.
I would prefer non working Qubes as I don't want to deprive anyone of
working ones. Doesn't matter whether it's a 1, 2 or 3. I'm looking to
repurpose the cases.
Thanks!
> Is there anyone that has already built a tool to dump TU58-tapes on a Linux
> machine? I have the drive of course.
>
> There is PUTR. But it is DOS only and is written in assembler so it cannot
> be ported easily. The other option is running RT11 on a PDP-11, but then
> there is the hassle of getting the dumps off the RT11 file system.
>
>
> It is probably not too difficult to use relevant parts of the various TU58
> Unix implementations out there to do something quickly, but if someone has
> already done it, it would be great to not reinvent the wheel.
>
> I have approximately 80 11/730 and 11/750 console and diag tapes that
> need reading.
Just a thought - if the TU58 connects via serial, then what about running
SIMH and giving it a serial device which is connected to the TU58? That
could fix both problems - how to talk to the device, and how to deal with
the data on the tapes.
John
Liam Proven wrote:
> I don't know. There is a huge amount of tradition and culture in
> computing now, and as a result, few people seem to have informed,
> relatively unbiased opinions. There hasn't been much real diversity in
> decades.
>
> 25 or 30y ago, people discussed the merits of Smalltalk or Prolog or
> Forth; now most people have never seen or heard of them, and it's just
> which curly-bracket language you favour, or does your preferred
> language run in a VM or is it compiled to a native binary.
Agreed. While I'm much more favorably disposed towards C than you are,
the increasing homogeneity of almost all modern languages is
discouraging and, I think, detrimental to the field as a whole. Forth
and Smalltalk alike were eye-openers when I discovered them (and
Smalltalk in particular was a breath of fresh air, after I'd spent
years failing to ever really grok OOP with the likes of C++ and Java,)
because both presented genuinely *different* and beautifully
consistent ways to think about structuring and specifying a computer
program. These days, though, outside of deliberately jokey
ultra-esoteric languages, it's pretty much just a bunch of
domain-specific Java/Javascript knockoffs from horizon to horizon.
> I am just surprised that this (to me) rather inelegant design survived
> and got to market, given what you've said about the same company's
> ruthless drive for cost-cutting removed one PCB trace even though it
> killed floppy-disk performance, or wouldn't use an extra ROM chip
> because it was too expensive.
>
> It seems inconsistent.
It's marketing - consistency there is a non-consideration, if not
actively striven against. The whole saga with CP/M on CBM was a
boondoggle - the CP/M cart existed because business customers wanted a
CP/M add-in to run their spreadsheets and their whatnot, but it didn't
end up being a good fit for reasons already stated (slow CPU, slow
disk, 40-column only.) The 128 improved on those points, but not
nearly enough to become competitive with the advancements CP/M
machines had made in that time, and in the process wasted precious
man-hours and drove up the cost and complexity of the unit - and all
the while CP/M had been losing ground to MS-DOS in the business market
for years! But marketing promised it, so it had to happen... :/
Tuesday night I was reading up to see what it might take to revive either of my Amiga 1200?s. As it happens, both appear to have fairly common failure modes. In reading up on the dead video, I learned that it?s often on the Composite Out, but not the monitor. I bought these two systems around ?97/98. I plugged the one with the dead video into the Monitor I?m using, and proceeded to use it for about an hour and a half. It works great with the Gotek floppy emulator.
On a whim, earlier today, when I placed the order with AmigaKit for A3000 batteries, I included the hardware needed to put a IDE-to-CF interface in both the A600 & an A1200, PLUS, a second Gotek. :-) It looks like I?m going to need them. :-)
Zane
Funny how wetware memory works. I have that issue of Popular
Electronics somewhere in my collection and would have seen the
article as I would read it cover to cover after it arrived in mail.
While looking at the issue again, remembered reading next article on
PLL's so probably read the Cyclops article, decided that $25 was way
too much for one chip and never bothered. However, I do have a lot
of old RAM chips so might give it a try some day. What I do recall
about that era that a 1024 bit SRAM cost about $10 in Canada. (That
was in days when we made a profit selling beer for $0.25 at TGIF).
Boris Gimbarzevsky
>I think a Stanford AI lab has one in a display case. Any others out there?
>
>It was supposedly "commercial" but I don't even remember ever seeing
>an ad for the Cyclops from Cromemco and I had a really good stash of
>Cromemco literature and hardware.
>
>I do remember the BYTE article where you pop the top off of a DRAM
>chip to make a Camera but that was 1983-ish, nearly a decade after
>the Cromemco Cyclops was supposedly "commercial". In the discussions
>I had in the 80's none of us seemed to know about the Cromemco
>Cyclops having preceded it.
>
>Tim N3QE
Bill, thanks in particular for the reference to the August 1976 Cromemco catalog. I definitely remember the Dazzler graphics on the cover but somehow had lost memory of the camera on the second to last page.
Tim
