Re: Giving away Garage full of computers
On Sun, Mar 13, 2016 at 11:43:43PM -0500, James Vess wrote: > I'm not sure what you mean by Printros? Printronixeses or something :-) I am heading back into Austin within the next 12 hours so if someone wants me to scout out something speak up quickly. Once I get back home I may take my shoes off and that will be the end for a few days. mcl
RE: DEC RK05 Emergency Retract Batteries
On Mon, 14 Mar 2016, tony duell wrote: I am told some later drives used the spindle motor as a generator when the power failed to provide the power for emergency retraction. Yes, the HP 7905/7906 does this for example. Christian
Re: Honneywell multics? from panels. the inline phots in this message folks -smecc
mån 2016-03-14 klockan 13:38 -0400 skrev Mouse: > > There is one axis along which I concede that things have advanced > > since Multics, which is away from monolithic kernels - > > Whether that is an advance or a regression depends on your priorities. > I see good arguments each way. > > > But the complete structing of the system around a segmented, > > single-level memory system (at least, in terms of the environment the > > user sees) is such a fantastic idea that I simply don't understand > > why that hasn't become the standard. > > Well, what was the largest virtual memory space available on various > machines? On the VAX, it was either one gig or two gig, depending on > whether you count just P0 space or both P0 and P1. When you're mapping > objects of uncertain size, that seems awfully constraining - and, > depending on the page table architecture in use, it can cost a lot of > RAM to get even that much; the VAX, for example, needs eight megs of > RAM to map one gig of space, and that doesn't even account for any > memory used to back any of that space. And, back in the heyday of the > VAX, eight megs was a lot of RAM. Which is one of the reason why the POWER architecture was done the way it was done. How much table space is needed is directly decided by the machine's amount of RAM (in POWER 1 at least.)
Re: A gold mine for anybody in Austin...
Ditto. Talked to him last year some time. I think he's a nice guy and cou himself in a situation that any of us and some do end up in. Too much of a good thing. Funnier is i always read his posts and could pretty much copy and paste them as my own. Either way i think he does have some nice gear but he knows like us the value and isn't looking to get rid of things afaik. Nothing wrong with that. At the time we talked we also spoke about trades being desirable more than cash flow. Not sure if he hangs out here or other forums. Original message From: George Currie Date:03/14/2016 10:52 AM (GMT-06:00) To: "General Discussion: On-Topic and Off-Topic Posts" Subject: Re: A gold mine for anybody in Austin... On Sun, 13 Mar 2016 18:50:56 -0500, James Vess wrote: > Probably true, but it's a weekend and I have time to deal with it so > we > will just see how it goes, I have some hope but low expectations. > I've communicated with him in the past. He seems like a nice enough fellow, but IMHO the prices he was asking for his stuff was way to high. His ads have been in the local CL for a long time now, so I assume he's not in a big hurry to sell or let things go at firesale prices (though maybe it's been long enough now that he'd be more open to it).
RE: DEC RK05 Emergency Retract Batteries
Interestingly(?) both my RK05 and RK05J had an assembly of 3, not 4, 2/3rd AA NiCd cells for retract, completely decayed of course. I replaced them with 3 discrete tagged NiMh AA cells (plenty of headroom) soldered and shrinkwrapped. They work fine, lots of retract force. The clip which holds them is shaped for only 3 cells so it seems as though there were at least 2 variants. I read the circuit diagram and could see that it would make little difference whether it was NiCd or NiMh (or for that matter 3 or 4 cells). I think DEC were a bit overgenerous with the trickle current (though IIRC NiCds were rather leakier back then). > From: tony duell > > The DEC RK07 (and I assume RK06) used 8 1/2 AA cells in a pack (like > 2 RK05 retract batteries in series). When I replaced those, I used 2 of > the cordless telephone batteries (that have been recommended for > the RK05) in series. > > -tony
Re: DEC RK05 Emergency Retract Batteries
> On Mar 15, 2016, at 4:08 PM, Robert Adamson wrote: > > Interestingly(?) both my RK05 and RK05J had an assembly of 3, not 4, 2/3rd > AA NiCd cells for retract, completely decayed of course. I replaced them > with 3 discrete tagged NiMh AA cells (plenty of headroom) From the various comments, it sounds like NiMH is a useable substitute. On the other hand, NiCd batteries are still readily available. paul
OKI if800 CP/M
Does anyone have, or has anyone used, one of these machines? Specifically the M10/M20 models, with 5.25" disks? I have a vendor box here with manual and CP/M 2.2 boot disk for the if800 and I've been trying to make a usable[1] image of the disk, currently with the Kryoflux and their dtc conversion tool. I sent the flux reads of the disk off to the KF team and they found it interesting enough to study, but there is precious little documentation out there about this machine, much less its disk format. Looking at the scatter plots of the magnetic flux on the disk, I can see that it's 40 track and double sided. Converting the dump to a DS/DD MFM disk image yields many warnings and errors, but also a file with plenty of discernible strings, so that's at least on the right track. Images of reads of the two sides done separately show alternating fragments of the strings of the full read, telling me that it is a contiguous volume using both sides and not two single-sided volumes. One ad I found (mostly in Japanese,) suggests that the if800 drives are 280K. That's an odd number (to me) for a 5.25" disk. -j [1] I have neither the real machine nor an emulator to use them, so this is mostly just an academic exercise in learning about disk formats and disk imaging, for now. But AIUI, if the disk's attributes are known, it should be browsable with a tool like cpmls from the CPMTools package.
Computer for sale
I am raising capital for a forthcoming venture dealing with vintage computers and thus am putting the following systems up for sale. Please visit the URL for photos and information (located in the Information file, if applicable) for each system. All prices are negotiable. PDP 8A System 1: http://vintagetech.com/sales/Big%20Iron/PDP%208a/Chassis%201/ Asking $900 System 2: http://vintagetech.com/sales/Big%20Iron/PDP%208a/Chassis%202/ Asking $450 System 3: http://vintagetech.com/sales/Big%20Iron/PDP%208a/Chassis%203/ Asking $300 Heathkit H11 http://vintagetech.com/sales/Big%20Iron/Heathkit%20H11/ Asking $750 ADM 3A http://vintagetech.com/sales/ADM%203A/ Asking $250 Friden 132 http://vintagetech.com/sales/Friden%20132/ Asking $1,500 ATR8000 (Atari 800 Z80 coprocessor box for running CP/M) http://vintagetech.com/sales/Micros/ATR8000/ Asking $500 Digital Microsystems CP/M computer http://vintagetech.com/sales/Micros/Digital%20Microsystems/ Asking $350 Integrated Computer Systems Microprocessor Training Lab http://vintagetech.com/sales/Micros/Integrated%20Computer%20Systems/ Asking $400 SWTPC 6800 http://vintagetech.com/sales/Micros/SWTPC%206800/Information Asking $950 Teleram 3000 http://vintagetech.com/sales/Micros/Teleram%203000/ Asking $650 Fulcrum Computer Products IMSAI 8080 clone http://vintagetech.com/sales/S-100/Fulcrum/ Asking $1,200 MITS Modem boardset http://vintagetech.com/sales/S-100/MITS%20Modem/ Asking $250 Polymorphic Systems POLY-88 http://vintagetech.com/sales/S-100/Polymorphic%20Systems%20POLY88/ Asking $1,250 Wang 380K Programmable Calculator with 362E terminal http://vintagetech.com/sales/Wang%20362E/ Asking $1,100 Please also see additional systems for sale (including a pair of IBM 3420 tape drives with 3803 controller) in the photos here: http://vintagetech.com/sales/Big%20Iron/ Please inquiry directly for more information. Thanks! -- Sellam Abraham VintageTech -- International Man of Intrigue and Dangerhttp://www.vintagetech.com Whatsoever a man soweth, that shall he also reap. The truth is always simple. * * * NOTICE * * * Due to the insecure nature of the medium over which this message has been transmitted, no statement made in this writing may be considered reliable for any purpose either express or implied. The contents of this message are appropriate for entertainment and/or informational purposes only. The right of the people to be secure in their papers against unreasonable searches and seizures shall not be violated.
Re: OKI if800 CP/M
On 03/15/2016 03:42 PM, Jason T wrote: [1] I have neither the real machine nor an emulator to use them, so this is mostly just an academic exercise in learning about disk formats and disk imaging, for now. But AIUI, if the disk's attributes are known, it should be browsable with a tool like cpmls from the CPMTools package. 22Disk has the definition, which is the same as the BMC IF800 (it was marketed under both brandings). I have samples in my files. --Chuck
Re: OKI if800 CP/M
On Tue, Mar 15, 2016 at 7:01 PM, Chuck Guzis wrote: > 22Disk has the definition, which is the same as the BMC IF800 (it was > marketed under both brandings). I have samples in my files. Ah, so it has, under both the BMC and the OKI names. I was going to try it with imgdisk and 22disk eventually, but I was in a KF experimentation phase.
Re: OKI if800 CP/M
On 03/15/2016 05:35 PM, Jason T wrote: Ah, so it has, under both the BMC and the OKI names. I was going to try it with imgdisk and 22disk eventually, but I was in a KF experimentation phase. A plain old PC with legacy FDC will work just fine. A little mouse tickling my memory indicates that the IF800 was one of the systems used by Gene Roddenberry. I don't recall if it was BMC or OKI, however. --Chuck
Re: OKI if800 CP/M
Ah, so it has, under both the BMC and the OKI names. I was going to try it with imgdisk and 22disk eventually, but I was in a KF experimentation phase. On Tue, 15 Mar 2016, Chuck Guzis wrote: A plain old PC with legacy FDC will work just fine. A little mouse tickling my memory indicates that the IF800 was one of the systems used by Gene Roddenberry. I don't recall if it was BMC or OKI, however. It might be necessary to go slightly below INT13h. I remember something weird about it, but can't remember what. Maybe it had invalid head numbers on the second side? In addition to the CP/M, the Oki if800 also existed with a version of Microsoft Stand-Alone BASIC; similar, but not a match for the NEC 8001. Don't know how wide spread that was, the disks that I worked on were some that Lee Felsenstein brought back from Soviet Union. I also once assisted Don Maslin with an NEC 9801 disk with the Stand-Alone BASIC format instead of either CP/M nor MS-DOS. For those not familiar, it has a directory in the middle of the disk. The directory consists of two parts, a linked list of clusters and a table of directory entries. Each directory had filename (some were 6.2 instead of 8.3), file size, and starting cluster number. Radio Shack Coco is one such, and the MS-DOS directory was inspired by it. Supposedly, Tim Paterson's company (Seattle Computer Products) shared a booth with Microsoft at NCC or the West Coast Computer Faire, and he liked the ideas behind the Stand-Alone BASIC directory structure.
Re: OKI if800 CP/M
On Tue, Mar 15, 2016 at 6:57 PM, Fred Cisin wrote: > >>> In addition to the CP/M, the Oki if800 also existed with a version of > Microsoft Stand-Alone BASIC; similar, but not a match for the NEC 8001. > Don't know how wide spread that was, the disks that I worked on were some > that Lee Felsenstein brought back from Soviet Union. > I also once assisted Don Maslin with an NEC 9801 disk with the Stand-Alone > BASIC format instead of either CP/M nor MS-DOS. > For those not familiar, it has a directory in the middle of the disk. The > directory consists of two parts, a linked list of clusters and a table of > directory entries. Each directory had filename (some were 6.2 instead of > 8.3), file size, and starting cluster number. Radio Shack Coco is one > such, and the MS-DOS directory was inspired by it. Supposedly, Tim > Paterson's company (Seattle Computer Products) shared a booth with > Microsoft at NCC or the West Coast Computer Faire, and he liked the ideas > behind the Stand-Alone BASIC directory structure. > > > I have a vague late-70's memory of RSX-11 putting the directory in the middle of the disk. -- Charles
Re: DEC H7104-D power supply tips?
On 3/14/16 10:46 PM, Mattis Lind wrote: tisdag 15 mars 2016 skrev Josh Dersch : Hi all -- My call for a VAX-11/750 a month or so ago actually bore some fruit (locally, even!) and as of a couple of weeks ago, I now have a very nicely configured 11/750 system taking up most of the basement. The previous owner got it after it was retired from a local(ish) university in the mid 1990s and it has not been powered on since then. Apparently at the time of its retirement the power supplies were exhibiting "random issues." (No more detail is available than that on the history...) At any rate, I went through the two power supplies (and the small pilot supply in the power controller) and found a lot of leaky capacitors (as in, yellow/brown goo was coming out of maybe 2/3 of them) so I went ahead and recapped the whole thing. At the moment I have things running on a dummy load in the 11/750 chassis. (the harnesses are still hooked to the chassis backplane, but all cards have been pulled, and the backplanes thoroughly checked for bent pins, etc.) The H7104-C (2.5V) supply seems to be working fine but the main 5V supply in the H7104-D is not doing so well (and as a result the other voltages it's supposed to be producing are also not present). The Power Controller lights up the "Reg. Fail" lamp (I don't know why the 5V Fail lamp isn't also on) and the 5V supply emits a loud (somewhere around 400Hz?) whine/squeal. I get about .3V out of it with a load. Without a load there's no squeal and I get about 5.6V, but that's not particularly useful. I've double-checked everything in the H7104-D and there's nothing obviously wrong (no caps installed backwards, no scorched components). At the moment the H7104-D is hooked up only to a dummy load, so it's not anything on the backplane shorting out or causing issues. This is another one of those cases where I've gotten myself in over my head with large, complicated power supplies -- anyone have any experience with these? Any tips? You can read the story of my 11/750 power supply repairs in this article: http://www.datormuseum.se/computers/digital-equipment-corporation/vax-11-750 Loud squealing noise was in my case due to short-ciricuit output rectifiers for the 5V. Check them. Then also chech the main chopper transistors. /Mattis Thanks to you (and others) for tips. I used the desoldering station at work today to remove the transistors for testing (the "motherboard" PCB in the 7104 is very thick and I was having no luck getting all the solder out of the vias with my tools at home). I found one bad 2N6547 in the lot (everything shorted to everything else) so I'll be replacing that tomorrow after a stop at Vetco on the way to work to pick up a replacement. All of the diodes that I checked looked OK. Fingers crossed that the transistor is the only issue here. Thanks again, Josh Thanks as always, Josh
Re: OKI if800 CP/M
On 03/15/2016 07:08 PM, Charles Anthony wrote: I have a vague late-70's memory of RSX-11 putting the directory in the middle of the disk. Not unknown in the CP/M world. For example, the NSC BLC 86/20 puts the CP/M directory on cylinder 39 of a 3.5" floppy. CP/M had all sorts of strange and original ways to map out a disk. The "list of clusters" wasn't new even in the 1960s. Take CDC SCOPE for example, using an RBT (list of clusters--Record Block Table), read into memory when a file was opened. ISIS II had a similar scheme of lists of blocks belonging to a file. Practically speaking, it was a lousy way to organize a floppy disk. Better to create contiguous extents for a file with an option for a number of additions, which keeps data belonging to a file together. Anyone who's tried to recover a MS-DOS floppy used as a work (lots of read/write/open/close activity) volume where both the root directory and FAT have been wiped out knows how hard that can get be. The stinker is that on a floppy, those were usually located on cylinder 0, where, incidentally, the FORMAT command also started writing... --Chuck
Code listings for the I4004 or I4040
I've been scanning the web in search of any code listings for these processors. Intel once had a library for some of these but it seems most is lost. I've found reconstructed listing for the Intellec4/40. I've seen just about all that existed in Intel's manuals. I even found an interesting listing that was to be used by the navy for plotting two ships courses ( interesting ) for intercept. Still, in general I'm coming up blank. Does anyone have a stash of paper tapes or listings? Dwight
