test-drb January 2018

test-drb@ccmp.vtda.org

177 participants
213 discussions

by billdegnan＠gmail.com

https://retropopplanet.files.wordpress.com/2011/06/vintage-computer.jpg I was not at this particular VCF out in California in the later 90's when this photo of a DEC exhibit was taken; the original picture from vintage.org is no longer hosted. Does anyone have a copy of the old vintage.org exhibit/photo archive? Bill

6 years, 2 months

IBM 9331-011 8" External Floppy Drive - eBay 183038271095

by cctalk＠gtaylor.tnetconsulting.net

Someone shared the following eBay auction in the comp.sys.ibm.ps2.hardware newsgroup and I figured that someone subscribed to cctalk might be interested: Link - IBM 9331-011 8" External Floppy Drive - eBay 183038271095 - https://www.ebay.com/itm/183038271095 -- Grant. . . . unix || die

6 years, 2 months

where to find ZCPR2, ZCPR3, ZCPR33, ZCPR34?

by spacewar＠gmail.com

On Tue, Jan 30, 2018 at 11:38 AM, Bill Degnan <billdegnan at gmail.com> wrote: > https://archive.org/details/LOGIC_AppleII_Disk-CPM014 > > is this what you mean? > While that's useful (thanks!), I'm really looking for the complete ZCPRn distributions, which included source code for the CCP replacement and the utilities etc. That's why ZCPR3 took up _nine_ volumes of the SIG/M library.

6 years, 2 months

No subject

by carlclaunch51＠gmail.com

The IPA is heated to 60C before the ultrasound is able to remove the oxide remnants, FWIW. While we can often get the entire smooth surface of the head clean with swabs and IPA, it is very difficult to clean all the material that forms in the cruciform trench recessed into the head (where the read/write and erase coil poles are visible). Heads can seem clean to the naked eye, but a good stereo microscope will insure that you have a clean and smooth surface. Regards, Carl Date: Fri, 26 Jan 2018 12:15:34 -0800 > From: Fritz Mueller <fritzm at fritzm.org> > To: "General Discussion: On-Topic and Off-Topic Posts" > <cctalk at classiccmp.org> > Subject: ultrasonic cleaning for disk heads > Message-ID: <9F2C2AC7-1B35-46F5-BD92-CC3DFD29FBFA at fritzm.org> > Content-Type: text/plain; charset=utf-8 > > I watched with great interest one of curiousmarc?s recent Alto videos, > wherein they clean a Diablo drive head ultrasonically. I?ve been > struggling a bit with my restored RK05 drives to completely clean the heads > after minor head crashes. Not being able to get them really sparkling > clean makes me always worried about running the drives for more than a few > minutes at a time, and a little nervous every time I spin them up?. > Scrubbing and scrubbing and scrubbing with IPA and kimwipes just doesn?t > seem to get all the crud off. > > I do have an alignment pack that I could use to re-align the heads after > removing them for a proper cleaning this way. Decent ultrasonic cleaners > aren?t terribly expensive and might be nice to have around the shop anyway > (I could also do all my eyeglasses :-) > > In the video, the heads are submerged in IPA in a glass cylinder, which is > then placed in the ultrasonic bath. > > Has anybody on the list here done this and have tips/advice beyond what > can be seen in the video? It looked very effective! I?m also having a > little trouble sourcing the squat form glass graduated cylinder online. > > cheers, > ?FritzM. > >

6 years, 2 months

ultrasonic cleaning for disk heads

by fritzm＠fritzm.org

I watched with great interest one of curiousmarc?s recent Alto videos, wherein they clean a Diablo drive head ultrasonically. I?ve been struggling a bit with my restored RK05 drives to completely clean the heads after minor head crashes. Not being able to get them really sparkling clean makes me always worried about running the drives for more than a few minutes at a time, and a little nervous every time I spin them up?. Scrubbing and scrubbing and scrubbing with IPA and kimwipes just doesn?t seem to get all the crud off. I do have an alignment pack that I could use to re-align the heads after removing them for a proper cleaning this way. Decent ultrasonic cleaners aren?t terribly expensive and might be nice to have around the shop anyway (I could also do all my eyeglasses :-) In the video, the heads are submerged in IPA in a glass cylinder, which is then placed in the ultrasonic bath. Has anybody on the list here done this and have tips/advice beyond what can be seen in the video? It looked very effective! I?m also having a little trouble sourcing the squat form glass graduated cylinder online. cheers, ?FritzM.

6 years, 2 months

ISO: PDP-11/24 SLU bulkhead

by derschjo＠gmail.com

Hi all -- Finally got around to fixing the H777 supply in my 11/24 (in the "L-box" BA11-L chassis) and now I'm looking at getting it to do something.? First order of business is getting the console SLU hooked up, and I'm missing the bulkhead panel for it.? There's a 20-pin ribbon cable that runs from the CPU backplane to this panel, which breaks it out into two 25-pin D-sub serial ports. According to the schematics, this is P/N 54-14218. Anyone have one of these lying around?? Otherwise I'll just build something of my own... Thanks, Josh

6 years, 2 months

QSIC update - v6 Unix boots and runs

by jnc＠mercury.lcs.mit.edu

> From: David Bridgham > Our plan is to produce a Unibus board as well, we just chose the QBUS > first. For no particularly strong reasons; I had working QBUS machines, and prototyping cards, etc, etc. > (actually, this should work with Q18 QBUS systems as well) Goodness, never thought of that. Hmmm.. it's probably enough hassle to mod the software (who ever heard of a 'QBUS map' on a QBUS -11 - but you'd need it to give DMA devices access to high memory) that it's probably just easier to go out and get Q22 hardware. Does anyone even have a Q18 /23? I think that was only the A model, right? I've never seen one. > we plan to also implement the Able ENABLE+ functionality In other words, a 'USIC' with Able ENABLE functionality added in. > This will, of course, require you to modify your OS to support this > non-standard memory. We should be programming compatible with the ENABLE, so for OS's where ENABLE support already exists, it should be a compile-and-go. > Noel has already done so for v6 Unix. Back in the day, with a real hardware ENABLE. PWB1, actually (pretty much V6). It wasn't too much work; one just changes the address definitions for the User and Kernel PARs from the DEC addresses to the Able ones, and recompiles all the kernel modules that touch them. One then has to set up the DEC User and Kernel PARs (which I did in the assembler startup, which was the only source module that took any serious changes). (If your OS uses Supervisor mode, well, err... :-) There are some other minor tweaks needed, e.g. this comment: / these routines are used to access /dev/kmem and look at possible / NXM locations in the system. The reason it uses this mechanism / is that some locations to be examined are on the bus before the / ABLE map, and thus cannot be examined by playing with the ABLE / map regs, e.g. using the standard u access routines .globl _fkbyte, _skbyte .globl _fkword, _skword Noel

6 years, 2 months

QSIC update - v6 Unix boots and runs

by dab＠froghouse.org

> That sounds pretty awesome. Good job there! Thanks.? Feeling good today after a bit of frustration with development not going faster. > Do you know how hard it would be to take this design and make a UNIBUS > version? I have an 11/34 languishing under the bench in my hardware > lab and one of the principal reasons for the languishing is that I > don't have any drives to go with it. Our plan is to produce a Unibus board as well, we just chose the QBUS first.? A Unibus version of the hardware ought to be a fairly straightforward adaptation of the QBUS board while the QBUS modules in Verilog will just have to be replaced with Unibus versions.? The busses work pretty similarly so we're expecting that to also be relatively straightforward.? Yeah, I've told myself that before.? :-) For the Unibus (actually, this should work with Q18 QBUS systems as well), we plan to also implement the Able ENABLE+ functionality which would give 11/70 size memory.? We'll have some SDRAM onboard that we'll use for RAM disks but we'll carve out 4MB of that for machine memory and include mapping tables to access it.? This will, of course, require you to modify your OS to support this non-standard memory.? Noel has already done so for v6 Unix.

6 years, 2 months

QSIC update - v6 Unix boots and runs

by dab＠froghouse.org

For those of you who are following along with our QSIC project, today we booted v6 Unix successfully for the first time.? We'd first tried this a week or two back but discovered that Unix does use partial block reads and writes after all and I hadn't implemented those yet.? We're running this on an 11/23 using the QSIC with an SD card emulating a couple RK05s. Moving on to a small RAM disk next so we don't have to swap off the flash memory.? After that, either a larger RAM disk using the SDRAM or an RP11 to get larger disks than RK05s. We're getting close to the time when we need to think about making our own circuit board rather than using the wire-wrap prototype we've been having fun with so far.

6 years, 2 months

QSIC update - v6 Unix boots and runs

by jnc＠mercury.lcs.mit.edu

> From: David Bridgham > today we booted v6 Unix successfully for the first time. As in, the OS image was loaded from the SD card, then started up using only the SD card for 'disk'. So this is a pretty major milestone. It's been a long road (I just looked, and we started on this in the summer of 2015), but we're finally getting there! The Unix file system, including the OS and all the various bits and pieces needed, like /bin/sh, etc, was prepared on a simulator (stock V6 won't run on a /23, which has no switch register), and then loaded into the SD card using 'dd' running on a Linux box. Our emulated RK11 doesn't do a perfect job of emulating an RK11 yet (e.g. for some reason we haven't yet looked into, the BDV11 ROM code won't load the bootstrap off the 'disk'; Dave had to manually load in an RK bootstrap using ODT), but enough is now working to let Unix load and run. > Unix does use partial block reads and writes after all For swapping, not for file-system I/O (which is all block-based). > We're getting close to the time when we need to think about making our > own circuit board rather than using the wire-wrap prototype we've been > having fun with so far. At which point we'll be able to supply them to anyone who wants one... It will be a while yet, but I think we are 'over the hump' on the project, with the OS booting and running properly. Noel

6 years, 2 months

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test-drb January 2018