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git-svn-id: http://unix-jun72.googlecode.com/svn/trunk@122 44b2186c-a14b-0410-8c95-595313601b93
143 lines
4.5 KiB
Plaintext
143 lines
4.5 KiB
Plaintext
Collection of notes on the hardware this should run on.
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------------------
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device layout per u0 src:
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address simh dev
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rk03/rk11 177400 disk RK
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dc11 174000 tty? (not supp?)
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tc11/tu56 177340 dec tape DTn (not showing up in simh?)
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rf11/rs11 177460 fixed head disk RF
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kw11-l 177546 clock CLK
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pc11 177550 paper tape PTR/PTP
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asr-33 177560 tty? TTI, TTO
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------------------
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man IV tap0 ... tap7 :
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"all eight files exist even though at present there are only two physical
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drives."
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man IV tty
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claims that tty is treated differently than tty0..tty5 and implies
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that it is not used in multi-user mode. This may pose a problem
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if DC-11 is not supported.. we may only be able to run in single user
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mode.
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"By appropriate console switch settings, it is possible to cause UNIX
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to come up as a single-user system with I/O on this device."
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man IV tty0 ... tty5
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says there are six tty devices. u0 srcs sets ntty to 8+1 (8 dc-11 plus
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one console?)
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man V core
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"It is exactly 8192+64 bytes long" 8k of user core.
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this agrees with the definition of core in u0 as 4096 words long.
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This also lines up with the statement that there was 24k ram:
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u0 sets orig to 0, and core to 16k and ecore to 24k (core+8k).
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------------------
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set rk3 enabled
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att rk3 rk3.dsk
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set rf enabled
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set cpu 11/20
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set cpu 32K ? there was really just 24k in the real machine
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-----------------------
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Disks:
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rf0 - 1024 blocks, always mounted, has root and swap.
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last 64 blocks (32kbyte) allocated to swap by u0.s
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u0.s can setup rudimentary fs on this if built with "cold=1"
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rk0 - 4871 blocks
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u0.s sets up rf0 as:
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- superblock layout
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- free storage map contains 128 bytes
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- inode map contains 64 bytes
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- allocate top 64 blocks "to unix" (960..1023)
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- allocate 17 blocks per process (nproc) (688..960 - 16 procs)
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- free blocks 687..34
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- zero out blocks 33..1 for use as inodes
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(and 2nd half of superblock which is unused?)
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- for each special inode i-1 to i-40 initialize it
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- mode 100017 (allocated, read, write, other read, othe write)
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- num links = 1
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- uid = 1 (yup, not root)
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- fill in timestamp info
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- write out premade i-nodes on i-41 .. i-47
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with premade directory data.
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i-41 root (with dev, bin, etc, usr, tmp)
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i-42 dev (with tty, ppt, mem, rf0, rk0, tap0 .. tap7, tty0..tty7, lpr, tty8)
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i-43 bin (empty)
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i-44 etc (with init)
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i-45 usr (empty)
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i-46 tmp (empty)
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i-47 init (binary, included in u0.s)
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special version that opens /dev/tap0 and reads files from it,
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creates them, chmods them and chowns them
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special init:
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- seek to 65
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again:
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- read 512 bytes
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- use first word as size, if zero, break out of loop
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- call create with name at offset 4
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- call chmod with byte at offset 2
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- call chown with byte at offset 3
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- read 512 bytes from tape
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- write min(remaining len, 512) to disk
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- decrement remaining len and loop if more left
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- close file
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- loop to again
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tape image format:
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for each file:
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first block:
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size : word, zero for end
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mode : byte
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(setuid, exec, user read, user write, other read, other write)
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uid : byte
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name : 8 bytes
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followed by ((size+511) / 512) blocks of data.
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EOF is marked by zero length file.
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-----------------------
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cpu
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probably 11/20 with 24kb (or should that be 24k words = 48k?)
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could be 11/45 though.
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pdp-11 releases:
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1970: 11/20, 11/15
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1972: 11/40, 11/45, 11/05, 11/10
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1973: 11/35
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"In 1971, when this manual was written, we had move off the original PDP-7
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to the PDP-11/20; it had 24KB of core memory, and no memory management
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hardware at all. "
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[...]
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"By this time we knew about the upcoming PDP-11/45, and had visited
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Digital in Maynard to talk about it; in particular, we had the specs
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for the floating-point instructions it supported. So the system
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described here included a simulator for the instructions (fptrap(III))."
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- http://www.cs.bell-labs.com/who/dmr/1stEdman.html
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(describing nov 3, 1971 manuals)
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-------------------------------------
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section VII pg 5 has "boot procedures" section:
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http://cm.bell-labs.com/cm/cs/who/dmr/man71.pdf
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------------------------------------
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http://en.wikipedia.org/wiki/PDP-11#PDP-11_instruction_repertoire
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Has a reference on all the AS instructions in the PDP-11. This may come in
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handy while fixing the OCR text.
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