https://github.com/larsbrinkhoff/kldcp
Attempt to make a bootable KLDCP disk image, and boot it with SIMH PDP-11/40
https://github.com/larsbrinkhoff/kldcp
Last synced: about 1 month ago
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Attempt to make a bootable KLDCP disk image, and boot it with SIMH PDP-11/40
- Host: GitHub
- URL: https://github.com/larsbrinkhoff/kldcp
- Owner: larsbrinkhoff
- Created: 2019-02-09T13:15:23.000Z (almost 7 years ago)
- Default Branch: master
- Last Pushed: 2019-02-10T11:47:54.000Z (almost 7 years ago)
- Last Synced: 2025-03-12T22:44:27.309Z (8 months ago)
- Size: 122 KB
- Stars: 2
- Watchers: 3
- Forks: 1
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
Awesome Lists containing this project
README
### Make a bootable PDP-11/40 disk image to run KLDCP on SIMH.
```
;ON DISK, SECTORS 1 AND 10 DECIMAL
;ARE "HOME BLOCKS" WHICH CONTAIN PHYSICAL DISK ADDRESS AND NUMBER
;OF SECTORS OF THE DIRECTORY. HOME BLOCKS AND DIR HAVE TO BE
;SET UP BY HAND. THE DIRECTORY IS A FILE IN THE ITS FILE SYSTEM.
;SECTOR 0 CONTAINS A BOOT PROGRAM WHICH IS READ IN BY THE BOOT ROM
;WHEN THE DISK BUTTON IS PUSHED. IT'S A PDP-11 PROGRAM. IT READS
;IN THE "PRIMARY BOOTSTRAP" FROM A DISK ADDRESS HARD-WIRED INTO IT.
;THE PRIMARY BOOTSTRAP FINDS KLDCP IN THE DIRECTORY AND RUNS IT.
;TO CHANGE THE DISK SIZE, YOU MUST CHANGE SEVERAL ADDRESSES IN THE
;HOME BLOCKS AND IN THE SECTOR 0 BOOT PROGRAM. OF COURSE YOU MUST
;ALSO CHANGE SEVERAL PDP10 PROGRAMS.
;THE FILE KLDCP;HOME BLOCKS CONTAINS A COPY OF SECTORS 0-15. OF THE DISK.
;THE FILE KLDCP;PRIMRY BOOT CONTAINS A COPY OF THE PRIMARY BOOTSTRAP.
;THESE ARE JUST REFERENCE COPIES, THEY AREN'T STORED IN THE ACTUAL
;SPECIAL DISK ADDRESSES WHERE THOSE THINGS GO.
;THERE IS ALSO AN INDEX FILE AND A BIT MAP, WHICH WE DON'T USE.
;THEY ARE SET UP TO BE UP IN THE MAINTENANCE CYLINDERS SOMEPLACE,
;TO MAKE KLDCP HAPPY, ALTHOUGH IT DOESN'T USE THEM EITHER.
;ALSO, THE FIRST 6 SECTORS OF CYLINDER 406 (DECIMAL)
;CONTAIN THE "PRIMARY BOOTSTRAP." THIS HAS TO BE SET UP BY HAND.
;ALLOCATION OF CYLINDERS ON AN RP04:
; 0-405. ITS FILE SYSTEM
; 406. PRIMARY BOOTSTRAP, KLDCP NOT-USED FILES
; 407. DSKDMP BOOT AND SWAP AREA
; 408. NOT USED
; 409. NOT USED
; 410. DDT BOOT AND SWAP AREA
;FORMAT OF SECTOR 0:
; ONE PDP-11 WORD PER PDP-10 HALFWORD
; RH(20) IS THE CYLINDER NUMBER OF THE PRIMARY BOOTSTRAP
; IT'S ON HEAD 0, SECTORS 0-4
```