test-drb January 2013

test-drb@ccmp.vtda.org

222 participants
294 discussions

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by jcw1231＠pacbell.net

hey have a look http://bit.ly/14tqlrm JC

11 years, 3 months

Looking for Appendix to HP 3.5" disc drive service manual (disc commands)

by john_a_s2004＠hotmail.com

On Wed, Jan 30, 2013, Glen Slick wrote: > Not the exact manual you were looking for but might have the same > information. This scanned copy includes pages Appendix A-1 through > A-36. > http://bitsavers.trailing-edge.com/pdf/hp/disc/5957-6584_9123D_3.5_Flex_Dis… Thanks Glen that's great, must have been a few minor corrections to Appendix A in this update to the original service manual. I was interested to read about the differences between the 9121 and 82901 commands, eg the 9121 supports a superset of the 82901 commands and so should be fully backwards compatible. One difference I have noted is using HPdir the 9121 appears to faster than the 82901, in that on a fast PC HPdir has to be slowed down to work successfully with the 82901 (eg by enabling logging) and works fine with the 9121, and on a slow PC both drives work fine with no attempts to further slow down the program. I've fed this back to the program author for further analysis. I can try and dump the drive firmware if anyone is interested in doing a detailed comparison. Regards, John

11 years, 3 months

Need help with PDP-8/A, VTServer & PDP-11

by charlesmorris800＠centurytel.net

A frustrating evening in vintage computer-land, as you will see. Also the drive belt popped off my 33ASR during the fun. And Windows Networking to the old PC I use to run VTserver was initially nonfunctional as usual, but I digress. I fired up my PDP-8/A after a long hiatus, and it won't boot OS/8 any more (on boot, the RL02 immediately flashes its Fault light briefly but then becomes ready again, and the system halts). The drive seems to be working without errors at least according to the short test programs from the user's guide I keyed in - I don't have a diagnostic pack - but reading the status register shows no error bits set, and the Oscillating Seek program also runs properly... Anyhow, I figure that the OS/8 pack might have become corrupted, so I attempted to reload it on my 11/23+ system (which IS working and passing memory tests) using VTserver, which is how I created it the first time. However, since I last successfully did it, I've upgraded the 11/23+ boot ROMs to the KDF11B-BH V1.0. This is the only hardware change. Not sure if that has anything to do with the problem, which is: When attempting to download the disk image, the copy portion of the program loads (starting at 140000) but won't execute, halting at 140002. I discovered that I had the Halt switch set. If the Halt switch is NOT set, when execution is supposed to begin, instead the 11/23+ says "ERR 4 MMU ABORT" and also won't accept the incoming disk image data! Do I need to go back to the original boot ROM in order to use VTserver (i.e. is there some change made to ODT that is messing things up?) Also, does anyone have a paper tape version of the RL02 diagnostics for PDP-8? thanks Charles

11 years, 3 months

HP LIF floppy disks and bad sectors

by john_a_s2004＠hotmail.com

Glen & Christain, many thanks for the information, and the pointer to the 9895A service manual at http://www.hpmuseum.net/exhibit.php?hwdoc=262The manual also has this to say: p.37:Before reading or writing a sector of data, the controller must position the read /write head of the disc drive over the desired sector. To do this, the controller sends signals to the disc drive to step the head to the desired track. The controller then begins to read the disc. Track and sector information is stored as a preamble to each sector, and the disc is formatted in a manner to allow the controller to detect the beginning of a preamble. On finding a preamble, the Z80A first checks that the track number is correct. If not, it will continue to step the head until the correct track is found. p.43 has figure 2-3 Track Format. This shows each sector consists of (ignoring gaps):ID Field made up of:- Sync up Bytes- Address Mark (AM) [in other manuals refered to as IDAM]- ID Information (bytes indicating the logical track, head and sector address)- CRCData field made up of:- Sync up bytes- Address mark [in other manuals known as Data Address Mark or DAM]- Data- CRC p.45 Address MarksID AM : Data pattern = !70Defective Track AM : Data pattern = !F0 At the command set level, a clear D bit indicates an ID AM in the ID field, and a set D bit indicates a defective track AM in the ID field. p.86 Start of Appendix A, 9895A Disc Memory Command Set p.89 - has description of the D bit. p.95 Shows the Command Table. p.105 'Request Logical Address' Purpose: The 9895A returns bytes indicating the current target address. This command is used to determine the address of the offending sector after a data error has occurred. p.106 'Request Physical Address'.Purpose: The 9895A returns bytes indicating the physical cylinder on which the head actuator is positioned. This is useful for calculating the number of invisible tracks between the outer-most track and the current track. This is done by subtracting the physical cylinder address from the target cylinder address. P1.31 Describes the Initialize command, and P.133 the Format command. Together these sections describe use of the D but and invisible tracks. To conclude, information such as the IDAM content won't be readable by a PC with a normal FDC, so this approach looks limited. I am in touch with Ansgar reading his wonderful hpdir project, which I am using with my Series 80 disks on an 82901M drive, so will point him here for a bit more light reading ;-) Regards,John

11 years, 3 months

Nice Direct View Storage Tube Demonstration

by legalize＠xmission.com

<http://computergraphicsmuseum.org/2013/01/30/nice-direct-view-storage-tube-…> -- "The Direct3D Graphics Pipeline" free book <http://tinyurl.com/d3d-pipeline> The Computer Graphics Museum <http://computergraphicsmuseum.org> The Terminals Wiki <http://terminals.classiccmp.org> Legalize Adulthood! (my blog) <http://legalizeadulthood.wordpress.com>

11 years, 3 months

wanted: German translation of magazine article

by LYNCHAJ＠YAHOO.COM

Hi! Is there any German speaking builder who would be willing to translate an article for a well-known European hobbyist electronics magazine? (You'll recognize the magazine but I'd rather not post that here for privacy concerns) One of the N8VEM builders, Oscar, has written a great article in English on the N8VEM project. We have interest from the magazine but of course they want the article in German. Would someone who is proficient in German please volunteer to help us out? Thank you very much in advance! I appreciate your support! Have a nice day! Andrew Lynch

11 years, 3 months

Cheap Teletype rools by the case on eBay

by wmaddox＠pacbell.net

Item # 160965266758 >From the listing: Part # 21-370, 8-7/16" X 370' of 16# bond paper, 1" cardboard core, 12 rolls per case, 99 cases available $30 per case, quoted $20 shipping to my location in California No connected with the seller, other than ordering a few. --Bill

11 years, 3 months

do you need to tear the metal shutter off of a modern 3.5: floppy for it to work in an SMC-70?

by rampaginggreenhulk＠yahoo.com

this I was told. Anyone?

11 years, 3 months

FAFNER is shut down

by fraveydank＠gmail.com

http://northtech.us/content/20130123/end-era-rip-fafner I only got to use it a few times, but it was nice to be able to connect to some real iron (I still have an account on the LCM's 11/785, I think). Service is continued on an Alpha DS20, but my username seems to be a bit broken at the moment. Many thanks to Dr. Ulmann for running such a majestic machine at considerable personal expense for all to use! - Dave

11 years, 3 months

wanted: German translation of magazine article

by rampaginggreenhulk＠yahoo.com

Why not just put it in a web documwnt and let google do it? Most of it... ------------------------------ On Tue, Jan 29, 2013 3:55 PM PST Andrew Lynch wrote: >Hi! > > > >Is there any German speaking builder who would be willing to translate an >article for a well-known European hobbyist electronics magazine? (You'll >recognize the magazine but I'd rather not post that here for privacy >concerns) > > > >One of the N8VEM builders, Oscar, has written a great article in English on >the N8VEM project. We have interest from the magazine but of course they >want the article in German. > > > >Would someone who is proficient in German please volunteer to help us out? >Thank you very much in advance! I appreciate your support! > > > >Have a nice day! > > >Andrew Lynch >

11 years, 3 months

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test-drb January 2013