He's asking about DEC Large Computer Group systems - DECSystem 10 or 20. I'd love to have one myself. -- Tony Sent from my iPhone On Aug 12, 2013, at 11:29 PM, Adrian Stoness <tdk.knight at gmail.com> wrote: wrote:

We have a KI and multiple KLs and KSs. We really want a KA, too. :-) --

Hello. I need some help, as I'm struggling with some pieces of old code of which I have only the macro-11 object files of. So, I'm looking for a disassembler which can read the .obj file and create a .mac file from it. I tried Google to find something, but alas, nothing to be found :( So, it there someone who has such a program? (BTW, I'm using RSX-11M V4 Thanks, Ed -- Dit is een HTML vrije email / This is an HTML free email. Zeg NEE tegen de 'slimme' meter.

Hi all Would anyone know where I can find a IBM 5440 diskdrive, or even better : a Philips 6875? They both use IBM 5444 cassettes, although with a different number of segments per track Nico -- I am using the free version of SPAMfighter. SPAMfighter has removed 1085 of my spam emails to date. Get the free SPAMfighter here: http://www.spamfighter.com/len Do you have a slow PC? Try a Free scan http://www.spamfighter.com/SLOW-PCfighter?cid=sigen

Hi all Would anyone know where I can find a IBM 5440 diskdrive, or even better : a Philips 6875? They both use IBM 5444 cassettes, although with a different number of segments per track Nico

On 8/15/13 3:26 AM, Nico de Jong wrote: There were many, many companies that made OEM 5440-style disk drives, most had slightly incompatible interfaces or cabling from each other. Are you sure what you are looking for are real IBM drives? Looking at the X121x drive service manuals at http://p800.wikispaces.com/Docs those drives are clearly European designs at quite unlike IBMs (TTL logic and different head positioning technology). The 2.5 vs 5 Mb difference will be 200 vs 400 tracks.

Hi Nico, I'll check for any IBM labels when I get home on Saturday, but I don't recall seeing any. Physically, the drive looks suspiciously similar to the IBM 5444 at http://www.theinquirer.net/inquirer/news/2074995/ibm-pictures-hardware-base…, including the location of the spindle motor, and the big clamps on the side. The actual data to/from the drive is almost raw; there's just a bitstream (at TTL level) from the controller to the drive to write, and from the drive to the controller to read. So, other than amplification and bit-shaping there is no processing in the drive (no de-serialization); there is a fair bit of electronics in the drive for seeking and head selection, though. What does your interface look like? The CDD (cartridge disk drive) controller in the P850 has a 74 pin card edge connector. Does your controller look like the one in this picture on my website: http://p800.wikispaces.com/CDD ? Camiel On Thu, Aug 15, 2013 at 5:22 PM, Nico de Jong <nico at farumdata.dk> wrote: > > ----- Original Message ----- From: "Al Kossow" <aek at bitsavers.org> > To: <cctalk at classiccmp.org> > Sent: Thursday, August 15, 2013 3:09 PM > Subject: Re: IBM 5440 > > >> On 8/15/13 3:26 AM, Nico de Jong wrote: >>> >>> Hi all >>> Would anyone know where I can find a IBM 5440 diskdrive, or even better >>> : >>> a Philips 6875? They both use IBM 5444 cassettes, although with a >>> different >>> number of segments per track >>> Nico >>> >> >> There were many, many companies that made OEM 5440-style disk drives, >> most >> had slightly incompatible >> interfaces or cabling from each other. Are you sure what you are looking >> for are real IBM drives? >> >> Looking at the X121x drive service manuals at >> http://p800.wikispaces.com/Docs those drives are clearly European >> designs at quite unlike IBMs (TTL logic and different head positioning >> technology). The 2.5 vs 5 Mb difference >> will be 200 vs 400 tracks. >> > Well, when I look at the product specification, it is specified that ibm > 5444 cartridges are used. The way I read the hardwaredocumentation, the > Philips machine takes the raw data, which could/should mean that no > logic/pre-handling is done in the drive. Of course I could be wrong. > I'll take a look at the p800 docs. > > Camiel, should there be an IBM label besides the X12.. drives you have? > Or > maybe something else indicating where the drive came from? > > > Nico > > -- > I am using the free version of SPAMfighter. > SPAMfighter has removed 1086 of my spam emails to date. > > Get the free SPAMfighter here: http://www.spamfighter.com/len > > Do you have a slow PC? Try a Free scan > http://www.spamfighter.com/SLOW-PCfighter?cid=sigen > >

This sort of interface was quite common on hard disk units at that time. SMD, for example has high-ish level seek, select, etc lines but raw data to/from the head amplifiers. So do most DEC drives (RK05, RLs, RK06/07,etc).

I think RK)5s do too, and maybe some of the other DEC drives. I am not sure about the Philips X1215, etc, but I can easily look it up. IIRC the

HP7900 drive does not include the data separator, it's in the controller. I had considered using an RK05 or an RK03 in place of the HP drive on an HP9880 system, this is one thing I would have to sort out (it is not difficult!).

IIRC the Shugart SA4000 drives had a clock track on the disk and a fixed hed to read it. The drive provided both the read _and write_ clocks to the controller.

-- I am using the free version of SPAMfighter. SPAMfighter has removed 1096 of my spam emails to date. Get the free SPAMfighter here: http://www.spamfighter.com/len Do you have a slow PC? Try a Free scan http://www.spamfighter.com/SLOW-PCfighter?cid=sigen

On Sat, 17 Aug 2013, Tony Duell wrote: I have the impression that the X1215 is just a rebadged CDC Hawk, i.e. a normal SMD drive. At least the P825-007/P825-008 is a standard CDC module drive (see P856M/P857M system handbook pages 17-22 to 17-25).

Me too, but the HP drives spin at 2400rpm instead of 1500rpm. You would have to modify the controller for the lower transfer speed.

How many KA was made?

On Tuesday (08/13/2013 at 08:46AM +0200), Pontus Pihlgren wrote: Interesting pictures. I am curious why machines of this era often have a "VOLTAGE" adjustment on the front panel? Was it really neccessary for an operator to adjust some voltage setting as the machine ran thus requiring that adjustment to be easily accessible on the front panel? What is it about the design that requires this? Why wouldn't the voltage adjustment be on the back or down inside where some knob twiddler can't get to it? It looks like the knob turns a variac so it's adjusting an AC voltage while the meter reads DC... so is it perhaps adjusting the AC mains input to a/the power supply, because the mains voltage wasn't stable? The variac seems a little small for that but ... Curious.

On Tue, Aug 13, 2013 at 06:15:41AM -0500, Chris Elmquist wrote: I dimly remember (probably from the Gordon Bell book?) that KO+crowd were weirdly obsessed (or maybe normally obsessed given the known failure modes of the time) with marginal testing. So they liked to crank things up to the high and low limits every so often to find parts that were about to stop working at the nominal voltages. So I think that's what that is... John Wilson D Bit

On 13/08/2013 21:45, Robert Ollerton wrote: On the Honeywell L66 and similar (so possible the Multics Machines as well) the engineers diagnostic software could vary the voltages on the PSUs so it could check it worked "on Margins". A far as I remember we did this routinely. I believe the Ferranti Pegasus from 1953? also had adjutable supplies. This was a valve machine ... Dave G4UGM

OK. Thanks for all the input on the topic guys. It just struck me as interesting that they needed this adjustment on the front panel of the machine-- which implied that they needed to adjust it often. I guess it was a long forgotten art of making the machine easily servicable for their SEs :-) Chris On Tuesday (08/13/2013 at 02:33PM -0700), Don North wrote: -- Chris Elmquist

On Tuesday (08/13/2013 at 08:46AM +0200), Pontus Pihlgren wrote: Interesting pictures. I am curious why machines of this era often have a "VOLTAGE" adjustment on the front panel? Was it really neccessary for an operator to adjust some voltage setting as the machine ran thus requiring that adjustment to be easily accessible on the front panel? What is it about the design that requires this? Why wouldn't the voltage adjustment be on the back or down inside where some knob twiddler can't get to it? It looks like the knob turns a variac so it's adjusting an AC voltage while the meter reads DC... so is it perhaps adjusting the AC mains input to a/the power supply, because the mains voltage wasn't stable? The variac seems a little small for that but ... Curious. -- Chris Elmquist