test-drb November 1999

test-drb@ccmp.vtda.org

211 participants
749 discussions

by edick＠idcomm.com

Having aligned about 25 8" drives over the last 6 months, I can tell you that if your drive is "eating" your diskettes, the problem isn't with alignment. If it's damaging your diskette emulsion, it's likely that it's either missing the headload pad, or the head penetration is misadjusted. I don't know what the procedure for head penetration adjustment on your particular drive is, but most drives seem to require a couple of feeler guages and some glyptol to make sure it doesn't move when you're done. Before I'll consider LENDING anyone one of my no longer readily available alignment diskettes, I want to be dead certain it won't be chewed up as might happen with the misadjusted head penetration or missing headload pad, or written on as might happen with an inappropriately set-up drive or controller. Even a $1k deposit won't ensure I get back a thoroughly useable diskette, and I've not seen one for sale in over 15 years. Dick -----Original Message----- From: John B <dylanb(a)sympatico.ca> To: Discussion re-collecting of classic computers <classiccmp(a)u.washington.edu> Date: Monday, November 29, 1999 5:38 PM Subject: Needed: 1 IBM 8" alignment disk. >Before I find the highest building to jump off of, I though I might ask here >first.... > >I have a Sykes 7150 8" floppy drive (negibus PDP-8I) that I have invested a >half and hour in and have solved *most* of it's problems... It finally talks >to the PDP and I can select tracks, reset, read status, etc... once in a >while read a sector. > >I need a single sided 128 byte record alignment floppy. > >When I do a read now, the drive stays busy forever looking for the sector I >asked it for. (even if the head is on top of it). Since it was made in 1974 >with TTL chips it is only bright enough to sit there and *wait* for the >correct data to come by. An alignment disk would make life a lot easier. > >Anyone have one available? Please e-mail. > >P.S. The sooner the better.. this thing is eating original IBM software >diskettes from the early '70s > > >PDP-8 and other rare mini computers > >http://www.pdp8.com > > >

25 years

Needed: 1 IBM 8" alignment disk.

by CLASSICCMP＠trailing-edge.com

> Try formatting the disk. If you still can't read >back, an alignment disk won't help. I'd be willing to bet that the Sykes hardware in question isn't capable of formatting a raw 8" floppy. Remember, we're talking large boards packed full of SSI TTL here, and the formatting functionality usually wasn't present. (Besides, at the time all 8" floppies came preformatted.) > Check that the head(s) >are clean and, if single sided, that the pressure pad is not >tilted. It is rare that the alignment is off unless someone >fiddled with it. 100% true. Unless it's been physically abused or someone decided they needed to "tweak" the alignment, it's probably right where it should be. And the advice to check the pressure pad is right on the money, too! Tim.

25 years

Unkonwn QBus card... anybody know what this is?

by CLASSICCMP＠trailing-edge.com

>Hi, all! I recently purchased a large batch of old QBus cards to expand >some of the systems in my collection, and one of the cards in the batch >is rather unknown to me... I know its some kind of disk controller, >guessing MSCP ST-506 but I'm wondering if its SCSI because i'm seeing >some resistor packs on the board that could be terminating resistors, >I suppose... anyways, here's the information: > >(Label on top of large 48 pin IC) > "TD Systems Inc. > Lowell, MA - USA > VIK/QDT #2111" > >(Label on 28 pin ROM) > "Viking > Q/B A4.0" It's a Viking QDT, a Q-bus host adapter for SCSI disks and tapes. (That's what the "DT" in QDT means.) -- Tim Shoppa Email: shoppa(a)trailing-edge.com Trailing Edge Technology WWW: http://www.trailing-edge.com/ 7328 Bradley Blvd Voice: 301-767-5917 Bethesda, MD, USA 20817 Fax: 301-767-5927

25 years

Needed: 1 IBM 8" alignment disk.

by dylanb＠sympatico.ca

-----Original Message----- From: CLASSICCMP(a)trailing-edge.com <CLASSICCMP(a)trailing-edge.com> To: Discussion re-collecting of classic computers <classiccmp(a)u.washington.edu> Date: Monday, November 29, 1999 8:44 PM Subject: Re: Needed: 1 IBM 8" alignment disk. >>"I'd be willing to bet that the Sykes hardware in question isn't >>capable of formatting a raw 8" floppy." It cannot format anything. > >>Is there any reason to beleive this device used standard SD soft-sectored >>discs, and wrote in the same format as IBM used? > >Does the Sykes claim to be RX01-compatible? If so, it ought to be able to read >standard IBM 3740 floppies. No it doesn't.. When did RX01s come out? They mention in the manual that you can copy its disks with a IBM 3741 copier??? > >There are third-party-for-DEC-systems drives out there that don't >emulate RX01 or RX02, and use their own propietary data formats. The >AED 6200 is an example. > >Tim. >

25 years

Amstrad CPC 6128 Floppy problem

by pete＠dunnington.u-net.com

On Nov 29, 19:02, Tony Duell wrote: > > > > I have a CPC6128 which reports that there is no disk in the drive when I > > try to run a program or even |dir. > > > > I have opened the box up and it looks as if the drive isn't spinning up. > I don't notice > a disk-inserted sensor on the FD1 schematic in the 8256 service manual > (which I am pretty sure is the same drive), though, and it appears to > detect a disk in place by looking for index pulses (the circuitry around > Q5-Q8). I think that's right. The classic symptom of the very common drive belt problem is that the disk isn't detected. Since the motor is pretty quiet, yo might not realise it's running but simply not driving the spindle. > These drives are well-known for suffering from drive belt problems, which > of course results in the motor spinning but the disk not turning. Could > that be the problem with your drive? *Very* common. After a few years disuse, the belt goes slack. In a pinch, you can replace the belt with a flat rubber band to prove the rest of the drive is operational, but it won't be completely reliable. The belts are easy to get, at least here in the UK, and quite cheap (a pound or so) if you don't buy the branded Amstrad spare part. However, they're flat belts and not very stretchy, unlike most round- or square-section cassette belts, so you do need to get the right size. -- Pete Peter Turnbull Dept. of Computer Science University of York

25 years

Needed: 1 IBM 8" alignment disk.

by dylanb＠sympatico.ca

-----Original Message----- From: Al Kossow <aek(a)spies.com> To: Discussion re-collecting of classic computers <classiccmp(a)u.washington.edu> Date: Monday, November 29, 1999 8:31 PM Subject: Re: Needed: 1 IBM 8" alignment disk. >"I'd be willing to bet that the Sykes hardware in question isn't >capable of formatting a raw 8" floppy." > >Is there any reason to beleive this device used standard SD soft-sectored >discs, and wrote in the same format as IBM used? Yes, the drive was *sold* on the fact that it was IBM compatible... Remember, I *can* get it to read in a sector once in awhile... They recommend using IBM 128byte record floppy disks. (what was available in 1974) > >

25 years

Needed: 1 IBM 8" alignment disk.

by dylanb＠sympatico.ca

-----Original Message----- From: Richard Erlacher <edick(a)idcomm.com> To: Discussion re-collecting of classic computers <classiccmp(a)u.washington.edu> Date: Monday, November 29, 1999 8:31 PM Subject: Re: Needed: 1 IBM 8" alignment disk. >Having aligned about 25 8" drives over the last 6 months, I can tell you >that if your drive is "eating" your diskettes, the problem isn't with >alignment. If it's damaging your diskette emulsion, it's likely that it's No.. My "eating" implies I am sticking in original IBM software disks to old IBM minis and writing over the data on them. :-( >either missing the headload pad, or the head penetration is misadjusted. I >don't know what the procedure for head penetration adjustment on your >particular drive is, but most drives seem to require a couple of feeler >guages and some glyptol to make sure it doesn't move when you're done. > >Before I'll consider LENDING anyone one of my no longer readily available >alignment diskettes, I want to be dead certain it won't be chewed up as >might happen with the misadjusted head penetration or missing headload pad, >or written on as might happen with an inappropriately set-up drive or >controller. Even a $1k deposit won't ensure I get back a thoroughly useable >diskette, and I've not seen one for sale in over 15 years. The *moment* I get this drive up I'll be making IBM alignment disks for the planet! > >Dick > >-----Original Message----- >From: John B <dylanb(a)sympatico.ca> >To: Discussion re-collecting of classic computers ><classiccmp(a)u.washington.edu> >Date: Monday, November 29, 1999 5:38 PM >Subject: Needed: 1 IBM 8" alignment disk. > > >>Before I find the highest building to jump off of, I though I might ask >here >>first.... >> >>I have a Sykes 7150 8" floppy drive (negibus PDP-8I) that I have invested a >>half and hour in and have solved *most* of it's problems... It finally >talks >>to the PDP and I can select tracks, reset, read status, etc... once in a >>while read a sector. >> >>I need a single sided 128 byte record alignment floppy. >> >>When I do a read now, the drive stays busy forever looking for the sector I >>asked it for. (even if the head is on top of it). Since it was made in 1974 >>with TTL chips it is only bright enough to sit there and *wait* for the >>correct data to come by. An alignment disk would make life a lot easier. >> >>Anyone have one available? Please e-mail. >> >>P.S. The sooner the better.. this thing is eating original IBM software >>diskettes from the early '70s >> >> >>PDP-8 and other rare mini computers >> >>http://www.pdp8.com >> >> >> > >

25 years

do you still need XT parts?

by mdalene＠home.ctol.net

Originally I did not, as at the time I dumped all of my Xt's I just happened to get another ORIGINAL IBM-XT system. its an Original IBM-PC system. so to answer your question. YES!!! I need to find a working 8 bit Ethernet card for it (NE1000?) or a Compaticard II or IV controller to Handle High Density disks. Right now it has a SEgate 8bit IDE controller card, which I would like to replace with a MFM card (I only have TWO ST3251A/X IDE drives. IDE and I are not on talking terms thoughi, IDE HATES ME, I want my SCSI or MFM! I would love to find another 8 bit SCSI Trantor Controller such as the T130B with the manual/software. Email back to me or call me at 860-423-2214 after 6PM Eastern Standard Time. ask for Michele Marie. For this brute, I need a CGA Monitor or color Composite monitor. Right now the system has a CGA/Composite Video board, I am using the Composite output to drive a Tandy VM11 (Actually the monitor is being used next door to watch TV (yeah its GREEN, but surpisingly its works great with DIRECTTV Satalite television.)). I have been looking for YEARS to get a Commodore 1702 Composite Monitor, This Commodore monitor supports standard Audio/Video in additon to S-VHS! video!! (you need a custom cable to be made to bring the Lumance and Chromance out as two RCA plugs though). An IBM-AT style keyboard by BTC would be nice. its not a clicky but I had one long ago on an old Hyundai XT that I used to have. Got one of those hiding around. I am going forward this to clasiccomp computers list also. I will summarise the pieces I am looking for below in detail: 1 Trantor T130B Scsi card with disks 1 Commodore 1702 Color Monitor (for computer/TV use) 1 BTC AT style keyboard that works on Xts 1 A better Motherboard (groan) or a new Bios for the IBM-Pc board. 1 Working 8 bit Ne1000 compatible 10base2 card/w packet drivers NCSA Telnet. Scsi Hard drives, any size from 40mb and up. 1 Cassette cable for the IBM-PC computer More US computer power cords! Memory! especially 4mb x 9 by 30pin simms at least 60ns (for the big bad ole 486 Linux file server 1 8087 math coprocessor chip for the XT (system is only 4.77mhz Hyndai/Blue Chip computer system. While we are on the commodore side (I am making this request to anyone that can help me here. In addition to the 1702. does anyone have a originall Commodore 64/128/128D computer and working 1541 floppy snail (if you know commodore, you know why the drive is a snail, I found a 1571. Only need a serial cable and the 1571 disks for that one and a 1541), Serial cables for drive, power cords, Datasette unit, (I have an Okimate 120 printer, not sure if it works though, a manual for this would help). serial cables Communications software. Rs232 serial adaptor (the thing that plugs into the user port/or quicklink II adaptor, fastload cartridge, software disks. I gave mine away, (sighhh, I want one again). I think some of my books are still at my parents. Might go home during Christmas to look for them. A pearl of wisdom from the y2K newsgroups: ------------------------------------------------------------------------- Y2K appears to be the Baby Boomers mid-life crisis, and it has the potential to be a dandy. -- Anonymnous -- -------------------------------------------------------------------------- B'ichela On Mon, 22 Nov 1999, Jeff Jonas wrote: > I found a note that you were once asking for > a PC-XT hard disk controller. > Do you still need any parts? > > Jeffrey Jonas > jeffj(a)panix.com >

25 years

DG house numbered part xref/help with what *looks* like a mux...

by chris＠mainecoon.com

I was wondering if anyone has a DG house number to generic part cross reference somewhere (if not I suppose I'll start one). Pat of this is prompted by a part (not *yet* suspect) I ran across on a Nova 800 CPU1 board. From the prints it looks like it's a a quad 2-input mux like a 74158, but the pinouts are completely different and it's got wired-or outputs suggesting OC outputs. Select and enable are on 9 and 7 (I may have those switched); 1 = i0a, 2 = i0b, 3 = ya, 4 = yb, 5 = i1b, 6= i1a, 10 = i2a, 11 = i2b, 12 = yc, 13 = yd, 15 = i3a, 14 = i3b Of course, that's just the way it's drawn. It could be somewhat different :-) Does this part sound familiar to anyone? Best, Chris -- Chris Kennedy chris(a)mainecoon.com http://www.mainecoon.com PGP fingerprint: 4E99 10B6 7253 B048 6685 6CBC 55E1 20A3 108D AB97

25 years

trancor northern, oscilloscopes

by CLASSICCMP＠trailing-edge.com

>I just saw some rack mounted oscilloscopes out on the loading dock. They are >manufactured by trancor northern, and have a quad height slot available from >the rear of the unit (no cover for the slot). It has a dual height LSI11 >cpu board (DEC), and another dual height board installed(DEC). The second >unit is the same, except the second card has generic white handles. > >Does anyone know about these things? one rack has two of these, and >under them is a dual 8" floppy drive unit, that has a small ribbon >connector that connects to something via a 25 pin rs-232 connector. It's *probably* a multichannel analyzer (MCA), not an oscilliscope. MCA's look at pulse heights and generate real-time cumulative histograms of pulse height on the screen. Tracor Northern is one of the more prolific manufacturers of MCA's. I once got to look at a MCA from the late 1940's, and it was fascinating: the input pulse was amplified, then fed to a solenoid that kicked a ball bearing up in a ballistic trajectory. There were bins that accumulated ball bearings according to how hard they'd been kicked. Fascinating machine! Of course, modern MCA's use computers to do the counting :-). -- Tim Shoppa Email: shoppa(a)trailing-edge.com Trailing Edge Technology WWW: http://www.trailing-edge.com/ 7328 Bradley Blvd Voice: 301-767-5917 Bethesda, MD, USA 20817 Fax: 301-767-5927

25 years

← Newer
1
...
5
6
7
8
9
10
11
...
75
Older →

Jump to page:

2024

2023

2022

2021

2020

2019

2018

2017

2016

2015

2014

2013

2012

2011

2010

2009

2008

2007

2006

2005

2004

2003

2002

2001

2000

1999

1998

1997

test-drb November 1999