Tuesday, November 24, 2015

System Load Deck utility working perfectly now


I have fixed the issue with formatting for the phases that have reload table entries and get apparently good results doing a reload of a couple of phases. However, comparing the disk sectors still shows that the contents of the sector don't match after the first 45 word card is punched.

It looks like I am picking up random data rather than the remaining content of the sector. The cause was the CARD0 library routine, which corrupted index register 1 during its execution. I saved the register around the library call and got an almost perfect match of the disk sectors between the original source version and the version reloaded by my program.

The problem is in the last word of the sector - I see an extraneous word on the new version. This is another of those nuance issues - where the way the last card of a system load deck should be produced. It has to do with how the SLET entries interpret the starting core address and number of words. I studied examples of decks for a while in order to lock in my spec for the utility program.

I ran a large batch of phases, about 90, through the reload process which finished normally. However, since the last word or so of each phase is not correct, the disk did not boot up and work properly. This is understandable. I am still working on getting what seems to be the last issue for my utility corrected

Once I had resolved those problems, I did a partial reload and had the system boot up fine. I am going to set up an initial load of a 'fresh' cartridge and then do a sector by sector comparison of the disk, checking for any discrepancies. That will be the acid test for the correctness of the decks built by my utility program.

I ran the large reload again and did a DCIP utility disk compare, which found zero discrepancies on the system phase sectors 8 to F5 where my reloaded modules sat. I had to make a quick fix to the utility to spit out the phases without the 9s separator cards, so I can use the large file to do a full initial load of the system.

That fix done, I created my all phases deck and did a reload to validate it all before moving to the new cartridge. Then I used the DCIP utility to initialize a fresh cartridge and ran an initial system load using my generated phases. It worked perfectly! DCIP did a disk compare and the sectors holding the system phases (0008 to 0139) are a perfect match - SLET, Reload Table and all the phases themselves.

I am very pleased and can now use this tool for a number of interesting things.

  1. Reload the simulator disk cartridge with the phase decks I read from my own card decks that came with the 1130 system. That might uncover discrepancies which would warrant investigation. 
  2. Create the decks as input to the UCART utility which will build a distribution cartridge that will mirror the way an 1130 owner would receive the DMS2 system from IBM.
  3. Recreate phase decks from the cartidges I received with my 1130, since they have all the compilers (RPG, COBOL and FORTRAN)

I also discovered the documentation that came with the DMS2 V12 decks - which shows that the phases which are missing in my collection were never shipped. They are phases that didn't change in V12, so they may be sitting in the DMS2 V11 decks. The distribution cartridge would not have been a V12 version, thus the decks I have are applied as a reload atop a V11 system.

My card trays have an R2 V11 deck, which on a quick investigation appears to have the first DUP phase (01) which was missing from my V12 deck. The documentation for V12 shows that DUP phase 01 did not change for the new version. Its header card has an earlier assembly date, while V12 is 11/06/73 for all the V12 phases.

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