My last email was unclear...I have a few RK06 Data Cartridges and an
Alignment Cart Available. Contact me privately if you have an RK06 drive
and you're looking for carts. They look like RL02's maybe a hair thinner.
I paid a small amt, and I am looking to be reimbursed for the cost.
I have no RK06 drive. RK06 cartridges are NOT compatible with RK07's
according to the manual. If you're in the Landenberg, PA area stop by,
At some point I will publish a list of other DEC items I have in clean
> From: Jon Elson
> I'm not sure the original DEC PDP-10 (KA-10) used microcode
No, it didn't; in part because it pre-dated fast, cheap ROMs (the development
of which was a considerable task in the /360 project - the wonderful "IBM's
360 and Early 370 Systems" covers this is some detail). The KA10 is built out
of FLIP CHIPs which carried individual transistors.
Another fun KA10 fact: it used 'hardware subroutines' - i.e. a clock pulse
would get to a certain point, and get conditionally diverted through some
other circuitry, later to come back and continue where it left off. Whee!
I have numerous BA350 and BA356 enclosures available along with the power
I will sell separately, or try to configure to your request. Please contact
me off list.
Shipping from 61820, Champaign, IL area
I've been trying to figure out what is wrong with the 12V rail on my
H7861 (BA11-S) power supply. It's showing about 4.2V. The 5V rail is
Page 39 of the following schematics is the main part board of the PSU.
Going into the collector of Q3 is about 80V coming straight from T2 (I
think I measured it at about 100Hz), but the emitter is putting out the
4.2V, which is the same as the base voltage and output voltage. I tried
replacing this transistor because the hFE was about 80 and a good one
was about 120. Unfortunately it didn't do anything.
None of the capacitors look swollen and I don't see any leakage. There
is a smaller board which I think goes into J4. The 12V side seems to
have a 555 timer and adjusting the pot doesn't change the voltage at
My understanding of switchmode power supplies is very poor. Does anyone
have some pointers on what to check or what might be the possible cause?
Hopefully I can get my PDP up and running again... Only got about 20
minutes use out of it.
This is the first time I've run across a bunch of double-sided 8"
double-density floppies in RX02 encoding. I'm assuming that this is
what's known as the RX03. The system is identified on disk as RT11A.
Does anyone know of a program to extract the files from images of this
sort (1,025,024 bytes: 26x256 sectors/track, 2 sides, 77 tracks)?
I've tried John Wilson's PUTR, but it hangs when it sees the image--I
can mount the image, but then anything after that just hangs the program.
I'd prefer a Linux program, but DOS/Windows would be fine. Otherwise,
I'll sharpen my pencil and get coding...
Hi DEC Enthusiast's,
If I were to have to decide on just one model DEC PDP system to run in a DEC
Emulator, which one would be the most useful, versatile and has the most
software available for it?
I have only ever used a real PDP-8/e system way back in high school so I'm
not up to par on any other model of DEC PDP system and I only know BASIC on
the PDP-8/e so not much there either.
I hear a lot about the PDP-11. I found out that there were 16 major PDP
models at one time so I'm not too sure which one to pick.
I built Oscar Vermeulen's PiDP-8/I which I'm waiting on 1 part for. Other
than that project which is in a holding pattern at the moment, I have no
other PDP anything running in any form.
Back in the day when Bill Gates and company 1st started out, I had always
wondered how they developed their very 1st software program - Altair Basic.
I was pleasantly surprised one day when I saw a B/W photo of a young Bill
Gates bending over the operator at what looked like a very small computer.
Maybe it was just a terminal. I don't remember. I understand they did
software development on a DEC PDP of some sort.
Finding this out regenerated my interest in the DEC PDP line of computers.
I have many projects in the works already so I decided to setup a software
emulation of just one of the DEC PDP models. I have heard a lot about the
PDP-11 which if the information I read is correct was 16-bits. My PiDP-8/I
is 12 bits. I understand the PDP 10 was 36-bits and the PDP-15 was 18-bit.
The PDP-11 is the model I hear the most about.
I also have some experience on some version of a VAX when I was in the Air
Force so I'm thinking of getting a VAX emulation going at some point too.
So if I'm going to do this, what suggestions, pointers, experiences,
etcetera do you guys have for me. I am very interested in the DEC PDP
equipment though next to no experience so I have no basis to make a
decision. This is a serious request so I would definitely like to hear what
you all have to say. If you have read this far, thank you. Take care my
computerdoc at sc.rr.comhttp://www.cocopedia.com/wiki/index.php/User:Computerdoc
As the subject says. It's been stored in a garage for many years but is in
pretty good condition. Free for pickup.
Owner of Binary Dinosaurs, the UK's biggest home computer collection?
On 10/30/2017 03:44 PM, Paul Koning wrote:
> The timing is carefully orchestrated, including of course provision
> for cable delays.
I'm reminded of a unit manager at CDC that I worked with for a time.
His first job at CDC as a fresh EE out of UofMinn was to measure all the
loops of cable on the backplane of the then-new 6600 to which Seymour
had attached tags that read "TUNE".
One marvels at the fiddling that must have been involved getting the
thing to run. Fun with taper pins...
Cray was certainly a character. Another associate regaled us with his
experience outside Seymour's lab in Chippewa Falls, sitting with a
couple of others in a car on a cold dark winter night exchanging code
and listings with Cray's daughter at the door. He was not about to let