Distilled water (was re: Model 152 PSU dummy loads)

Just to be pedantic, as this is the Internet after all :-), distilled water is a pretty good insulator, but not a "perfect" one. Neutral (pH 7.0) water always has a very small amount of the molecules disassociated into H+ and OH- ions. However, as others have stated, the effective value of the wa

Re: Virtualizing AIX 1.3 - WAS::::Re: AIX for IBM PS/2

>> https://sites.google.com/site/rhdisk0/unix/aix/aixps2 >> > > Is anyone else having issues with that URL? I get a quick flash of a > legitimate web page before the browser fills up with ASCII garbage. No, it loaded fine on my browser.

Re: A tale of woe, including carelessness, stupidity and laziness....

> On 8/22/2015 4:11 PM, Eric Smith wrote: > In my mostly misspent youth, I once had the opportunity to visit a > facility where a now obscure supercomputer was developed. The product > manager was showing me around. Denelcor perhaps?

Re: Structured Fortran

At NCAR there was a structured Fortran preprocessor named IFTRAN that was in use for a long time. The earlier versions of the NCAR Local Network (NLNET), later renamed MASnet (Mainframe and Server network), as well as a variety of graphics packages were written in it. I still have the IFTRAN t

Re: Recovering 4mm tar tapes

> On Sep 12, 2016, at 11:00 AM, cctech-requ...@classiccmp.org wrote: > > Is the 2nd tape just bad and can't be read? Or do I need a > slightly different tape drive? It may be bad or perhaps it was written with a larger block size? I don’t recall what tar does if the tape was written with a

AC Filter Cap Brand Recommendations

Wouldn’t you know it, the same day I decide to order a ribbon and some paper for my HP 82905B (aka Epson MX80) printer, the AC line filter cap (C1 on the MFIL board), expelled its magic smoke rather impressively. After some cleanup, the printer has been banished to the garage until the smell di

Re: Looking for HP98034 / HP9895 ROM images

> On Oct 18, 2016, at 11:00 AM, cctech-requ...@classiccmp.org wrote: > > does anyone of you happen to have the images of the firmware ROM of > HP98034 module and/or of the HP9895 disk drive, please? I’ve sent F.Ulivi the contents of the single ROM version from my 9895A, along with some prelimin

HP 9872 Refurbishment

I hauled out my second 9872C today to clean it of rodent leavings and to scavenge the high voltage chart hold power supply board for my first 9872C. The table has some gouges in the surface, which appears to be a plastic film adhered to the table surface. Does anyone have experience repairing g

Re: Flex Disc options for the HP 9825

Excellent news! I eagerly look forward to this so I can get my 9825T talking to my 9895A! If you spin a PC board, I will be willing to purchase one or two if you end up with extras or are willing to coordinate an order.

HP 9875A usable for interchange with 85 or 9825?

I’m working on getting my 9875A dual DC100A tape drive operational, but have come across a strange issue. This 9875A seems to have the reversed sense of on which reel the rewind places the tape as compared to my 85B and 9825T (which agree is the left hand one as viewed when inserting the tape i

Re: Looking to read past EOT on DDS/DLT/LTO

For the NCAR Mass Storage System, when we upgraded our tape drives to Sun STK T1 models, we lost the ability to skip past the EOT mark with standard firmware. We asked Sun to provide a firmware modification that let us issue four or so reads after reaching the EOT mark, and the drive would

Information Request: unidentified HP 9825T instructions

I am working on the disassembly and commenting of the 98228A disk ROM for the 9825T, and my disassembler flagged two instructions as invalid. They are used inside a routine that copies blocks of words from various banks of the ROM into low RAM. The first, bit pattern 070113, is used immediatel

Re: Information Request: unidentified HP 9825T instructions

Tony Duell wrote: > My first thought, and it's probably wrong, is that these instrucitons > (which differ by one bit, so might be > setting/reseting something) are NOPs to the CPU, but are interpretted > by the memory mapping hardware in those > 9825s that have more than 64K or RAM and ROM total.

Re: Retro networking / WAN communities

> I'm running into issues with switches not supporting 10 / 100 Mbps management > interfaces for other equipment. Half duplex was apparently deprecated a few years back, and recent switches from Cisco (and probably other vendors) no longer support half duplex. We ran into this at work for long

Re: P112 Floppy Controller

The P112's floppy controller is the one in the SMSC FDC37C665IR SuperIO chip. The data sheet states it is a 2.88 MB "Licensed CMOS 765B Floppy Disk Controller" and claims 100% IBM compatibility (for what that's worth).

Not just slashed zeroes/ohs

Having gone through many mathematics courses it was common to also place a slash on the letter Z to distinguish it from the numeral 2. Also for persons from Europe where they slashed the numeral 7 to distinguish it from a numeral 1 that commonly had an initial small upward stroke at the top when

Re: Alphastation 200 login (Wayne S)

> On May 18, 2022, at 11:00, cctech-requ...@classiccmp.org wrote: > > Got my Alphastation to boot but i can?t logon because i don?t the > administrator password? Any ideas on how to get past that? It depends on the OS installed. For Unix-style OS you need to figure out the single user boot mo

[cctalk] double cctalk membership

I followed the suggestion in a previous message to logon to the new server and set my desired list settings. Now I show up with two subscriptions for my email address, one as "nonmember" and the new one as "member". It does not appear that I am receiving doubles delivery of messages, so I'm not

[cctalk] Re: HP9825A for sale

> On Apr 17, 2023, at 11:00, cctalk-requ...@classiccmp.org wrote: > For the HP, I think it's a fair asking price because of all the cables, > manuals, and accessories that he's got -- he's got all the SerialIO > stuff, so it would be a fun project (to me) to try to write a terminal > program and

[cctalk] Gb Ethernet and 10Mb links

FYI: The Ethernet standards dropped support for half duplex connections a few years back, so that if you have something that depends on half duplex links a recent Ethernet switch might not support it.

Replacing flat drive belts alternatives?

I would like to have both the drives in my HP 9895A working. Since flat belts for old equipment are becoming nearly impossible to find, has anyone had success replacing a flat belt with a toothed? Either by reversing the belt or by also replacing the pulleys? Or by the installation of an idler

[cctalk] Re: Gb Ethernet and 10Mb links

> On May 28, 2023, at 14:18, Paul Koning wrote: > > Dropped support for it on 10 Mb links? That seems like a crazy change to > make. I know it was defined but basically unused at higher speeds. No just the half duplex part of the standard. The 10 Mb/s full duplex links are still supported.

[cctalk] Re: Current SOA scsi disk emulators for DEC

I'm currently using a version 5 something (5.4 I think) of the SCSI2SD in my 11/83 to run 2.11BSD, it has worked well.

Q: Plotter bed repair with MonoKote?

> On Feb 18, 2019, at 11:00 AM, dwight wrote: > > There were a couple hp XY plotters that had the mylar plate delaminating. > I've reworked these with model airplane mono coat. Are you referring to MonoKote (www.monokote.com )? That looks perfect for repairing the g

Re: Raised Floors

The NCAR Wyoming Supercomputer Center has raised floors of about 20 feet. The auxilary cooling and PDUs are installed down there. Needless to say, you don't pull a floor tile there unless you are on the facility staff!

Re: Raised Floors

> On May 22, 2019, at 11:00 AM, cctech-requ...@classiccmp.org wrote: > From: Grant Taylor > > On 5/21/19 5:33 PM, Craig Ruff via cctech wrote: >> The NCAR Wyoming Supercomputer Center has raised floors of about 20 feet. > > Did the support posts go all the way down? O

Re: Raised Floors

I should have been more clear in my last response. The 2x2 grid of the floor tiles does not extend to the floor, but to an intermediate layer with wider spacing of the supports at the floor level.

Re: looking for a program - last gasp questions (Dr Iain Maoileoin)

Perhaps http://www.asciisector.net/ ?

Re: P112

Just in case someone else hasn't already responded, the P112 does not use DOS style fdisk partitioning for a hard disk. It is done in the BIOS image, and then the logical disks have to be initialized. This is described in the "P112 GIDE Construction.pdf" document. I've only used 3.5" floppies,

Re: 13W3 to HDMI/DisplayPort

Just bought an Extron RGB-HDMI 300 (A) that handles VGA and other RGB type signals and has HDMI output. I've connected it to my VAXstation 4000/60 (very successfully), and my IIgs (reasonable but this is at the low end of what the unit can manage). Output on either my Sony 46" TV or Apple 1600x1

Replacing cables sheaths?

Does anyone know of an effective technique to replace the sheath of a cable without needing to reterminate the ends? On all of the Apple power adapter cables I've used the plastic sheath starts to fall apart, but the adapter itself and the cable conductors are still useable. Something that resul

Re: Replacing cables sheaths?

Thanks for the suggestions. I currently have Rescue Tape brand self adhesive silicone tape on the cable, but it looks like it is causing corrosion of the spiral-wound metal shield wires. The wrap around heat shrink might cost more than just buying a new adapter! It looks like there is an 1/8" sp

Need HP 9114B PROM 09114-15521 Contents

The PROM in my 9114B committed suicide this morning, letting the magic smoke out. It was marked with part number 09114-15521, does anyone happen to have dumped the contents so I can program a new one? Thanks.

Re: Need HP 9114B PROM 09114-15521 Contents

FYI: I've received the PROM image, no need for anyone else to go to the trouble to extract it.

Microfiche reader spotted in Longmont, CO thrift store

If anyone along the northern Colorado Front Range is in need of a microfiche reader, it was reported to me that a Micro Design model 4010 is sitting in the Longmont Community Thrift store. My source didn't notice a price. The condition is unknown, but it appears to be reasonably intact, and a ce

Re: DEC 3000 (alpha) faultfinding

On the AXPpci33 board, the SROM is also an 8 bit device. What happens is that the CPU reads in a bit stream into cache at power up reset, where the specific bit stream is selected by the jumper position on the board. In effect the SROM can contain up to 8 bit streams. Some of them will make use

Re: DEC 3000 (alpha) faultfinding

According to the 21066 HRM, the processor loads its initial I-stream from the SROM. All Icache bits are loaded from the SROM, including the cache block metadata. The blocks are loaded in sequential order starting with block 0 and ending with block 255. For the 20166, the Icache is loaded LSB

Re: P112

I have a operational P112 with 3.5" floppies, GIDE/CF and CD-ROM. Do you know which ROM you have installed?

Re: Teac Mt-2st/20D-12-u

I used to have a SCSI interface version of that drive type, I made backups of my Mac Plus (I think it was) hard drive. Since I don't have it currently, I believe I gave it to a friend along with the rest of my Mac Plus peripherals. I don't recall the capacity of my specific drive, but it used

RE: SCSI2SD

I've also used a version 5.1 SCSI2SD on a VAXstation 4000/60 without problem.

Re: External SCSI Drives on DEC2000 AXP

Have you verified that the SCSI bus is terminated properly? A missing or improperly configured terminator can sometimes cause those sort of symptoms.