Lt Kernal Owners

[maraud]

Hey all,

Looking for anyone who's owned a Lt Kernal HDD subsystem...

I've acquired a 20MB unit recent and picked up a couple of 140MB 50 pin units to replace the existing 20MB unit with...  The reason I'm calling all hands is that I need to figure out how to format the 2nd unit..... I've read through the SYSGEN stuff online, but that seems to all be "start from scratch" kinda stuff and my goal is to add a 140MB unit and copy the data off the 20MB drive.... Mainly, honestly, because I hope the 3.5" unit will be quieter....

Anyone done anything of the sort?

Thanks!

[RobertB]

The reason I'm calling all hands is that I need to figure out how to format the 2nd unit..... I've read through the SYSGEN stuff online...

That means you've gone throught the information at

http://www.floodgap.com/retrobits/ckb/ltk/

...but that seems to all be "start from scratch" kinda stuff and my goal is to add a 140MB unit and copy the data off the 20MB drive....

It sounds as if you need a drive-to-drive copier that will copy the "partitions" with all of the data.  I've never heard of anything like that for the Lt. Kernal.  You might have to do it the old-fashioned way, i.e., format the new mechanism, transfer all the data from the old mech to floppies, and then reload all that data from floppies onto the new mech.

               Truly,
               Robert Bernardo
               Fresno Commodore User Group
               http://videocam.net.au/fcug
               July 25-26 Commodore Vegas Expo - http://www.portcommodore.com/commvex

[BigDumbDinosaur]

Any time you add or subtract physical storage to a Lt. Kernal system you must edit the SYSGEN disk and SYSGEN the system to make the new driver parameters take effect.  It isn't necessary to perform a physical format on the drive, as all SCSI drives are formatted at the factory.

Are you sure you read http://www.floodgap.com/retrobits/ckb/ltk/drives_edit.htm in its entirety?

BTW, there are no "partitions" on a Lt. Kernal system.  The storage is organized in logical units (LU) and user areas.  The former are software equivalents to the separate floppy drives in a Commodore or MSD dual drive unit.  The later work exactly like user areas in CP/M.  SYSGENing an empty drive (SCSI ID 0) will produce two default LUs, 0 and 10.  LU 0 corresponds to any single drive floppy unit and LU 10 is where the Lt. Kernal's disk operating system (DOS) is stored.  SYSGENing a system that aleady has a valid LK DOS on it will not disturb the current LU definitions.  However, it is wise to back up the system before SYSGENing or otherwise reorganizing your storage.

You need to carefully read all the Lt. Kernal documentation before you start fiddling with the system.  Otherwise you are going to have a hard time with what was the best hard disk subsystem ever developed for the C64/128.

[RobertB]

BTW, there are no "partitions" on a Lt. Kernal system.  The storage is organized in logical units (LU) and user areas.  The former are software equivalents to the separate floppy drives in a Commodore or MSD dual drive unit.  The later work exactly like user areas in CP/M.

Yup, that is why I put the term, "partitions", in quotation marks.

           Because it is easier to understand that way,
           Robert Bernardo
           Fresno Commodore User Group
           http://videocam.net.au/fcug
           July 25-26 Commodore Vegas Expo - http://www.portcommodore.com/commvex

[maraud]

Any time you add or subtract physical storage to a Lt. Kernal system you must edit the SYSGEN disk and SYSGEN the system to make the new driver parameters take effect.  It isn't necessary to perform a physical format on the drive, as all SCSI drives are formatted at the factory.

Are you sure you read http://www.floodgap.com/retrobits/ckb/ltk/drives_edit.htm in its entirety?

Yeah I've read thorough it several times (initially becuase I was trying to find a way to reverse engineer the PLC's - It's be supurb to be able to create new host adapters, becuase it is an AMAZING system.  I owned a CMD back in the day and while it was a lot easier to install, etc it can't touch the speed of the LtK.  I'm truly impressed as my BBS loads modules so fast, that you can't really tell the difference between this and when they were in the 1750.  I don't have a port expander unfortunately, so it' was one or the other.

And thank god it doesn't disturb existing LU's!!  In prepping my SYSGEN disk and verifying it worked it just "went" didn't realize it wouldn't prompt any sort of are you sure kinda deal.  I'll have to say I panicked a bit when reinstalled DOS, but was presently suprised that all of my data was still there.  I just had to redo the config settings is all.

Turns out the two 160MB units I got won't work because I can't disable parity....  So I just got a 4GB SCSI unit (of which I'll only use 160MB worth) and what I think I'll do now that I've seen how to add a drive, is add it, and copy the data over then remove the old 20 megger.....  Only thing though, is I presume you can't change the LU's, so I'll prob make a temp LU and use the different USERS to separate the data up during the whole backup / transfer process.

[BigDumbDinosaur]

BTW, there are no "partitions" on a Lt. Kernal system.  The storage is organized in logical units (LU) and user areas.  The former are software equivalents to the separate floppy drives in a Commodore or MSD dual drive unit.  The later work exactly like user areas in CP/M.

Yup, that is why I put the term, "partitions", in quotation marks.

           Because it is easier to understand that way

Actually it isn't easier to understand that way, because there are *no* partitions in a Lt. Kernal system and there are no analogs to a partition.  Using that term is as wrong as referring to the user areas in CP/M as subdirectories.  The only correct term is "logical unit."

Logical units on the Lt. Kernal are the direct analog of the individual drive mechanisms in a Commodore floppy disk.  If a Lt. Kernal system has been configured with LU 0 and LU 1, for all intents and purposes, the LK is like a dual floppy disk drive, whose mechanisms are referred to as 0: and 1: in Commodore DOS syntax.  If LU 3 is also defined, then 3: is also valid syntax.  If a file named junk.txt is located in LU 3, U 5 (user area 5), the syntax to open it, assuming the LK's device number is set to 8, would be:

    OPEN 2,8,2,"3:5:junk.txt"

It's important to use the right terminology, especially when someone is just starting out with the system.  Otherwise, he's going to find that the LK documentation doesn't agree with what he is reading here, resulting in unnecessary confusion and frustration.

[BigDumbDinosaur]

Yeah I've read thorough it several times (initially becuase I was trying to find a way to reverse engineer the PLC's

The security "fuse" has been intentionally blown in the PLDs (not PLCs) to prevent copying.  Back in the day, pirates tried several times to steal the design but never succeeded.

Turns out the two 160MB units I got won't work because I can't disable parity....

Parity is a jumper-selected feature.  See if you can track down the specs for the drives.  You may discover that there's a jumper on the embedded controller to enable or disable parity.

So I just got a 4GB SCSI unit (of which I'll only use 160MB worth) and what I think I'll do now that I've seen how to add a drive, is add it, and copy the data over then remove the old 20 megger.....

The maximum possible drive capacity that can be exploited by the Lt. Kernal is 320 MB.  All LBAs are computed in 21 bit arithmetic (SCSI-1 standard), but the offsets within an LU are computed with 16 bit arithmetic.  The maximum possible LU size is $FFFE 512 byte blocks or about 32 MB.  Up to 11 LUs are possible, of which 10 (0-9) are user-definable, giving you about 320 MB maximum aggregate storage.

Only thing though, is I presume you can't change the LU's, so I'll prob make a temp LU and use the different USERS to separate the data up during the whole backup / transfer process.

You set up one or more scratch LUs as you suspected and then autocopy files, which goes very fast.  You cannot resize an existing LU without destroying its contents.

[RobertB]

It's important to use the right terminology, especially when someone is just starting out with the system. 

Very well.  At this year's CommVEx I will try to refrain from using such general terms as "stuff", "thingy", and "hey, you". 

          Send in your well-worded questions to Peddle,
          Herd, Haynie, Mical, and Luck at CommVEx,
          Robert Bernardo
          Fresno Commodore User Group
          http://videocam.net.au/fcug
          July 25-26 Commodore Vegas Expo - http://www.portcommodore.com/commvex

           

[maraud]

The security "fuse" has been intentionally blown in the PLDs (not PLCs) to prevent copying.  Back in the day, pirates tried several times to steal the design but never succeeded.

Yeah that's really a shame - as it would be lovely to reproduce "new" versions of these HBAs!  Just kills me to think that when one of these PLD's go because of old age or my "effup" that it's a done deal!

[BigDumbDinosaur]

It's important to use the right terminology, especially when someone is just starting out with the system. 

Very well.  At this year's CommVEx I will try to refrain from using such general terms as "stuff", "thingy", and "hey, you". 

          Send in your well-worded questions to Peddle,
          Herd, Haynie, Mical, and Luck at CommVEx,
          Robert Bernardo
          Fresno Commodore User Group
          http://videocam.net.au/fcug
          July 25-26 Commodore Vegas Expo - http://www.portcommodore.com/commvex

         

Stuff and thingie are okay.  Dunno about "hey you" though.

I try to keep it light except when discussing technical features about a particular piece of hardware.  Back when the Lt. Kernal was still relatively new, many would-be users were thoroughly confused by features that were described using terms that were incorrect.  The partition one was particularly problematic because someone who had been exposed to MS-DOS running on a hard drive would think in terms of PC style partitions.  The Lt. Kernal's storage structure is a blend of Commodore and CP/M, the former expressed as logical units and the latter as user areas.  There is no partition table anywhere and no resemblance of any kind to the PC hard disk architecture.