Fortran on Titan: System Note 3
B C Chapman
15 August 1966
1. General
System note 1 contained an error in the reference number of the ASP manual - it should have said A.E.R.E, Harwell Report R4285.
2. Modifications to the S2 Manual
- 3.4
- Note that -A**B is evaluated as -(A**B)
- 8.3
- PUNCH, This statement is available, but results
in the production of 7 track paper tape, unless otherwise specified.
- 9
- READ TAPE, WRITE TAPE, REWIND, READ DISC, WRITE DISC These statements are now available for use on Titan.
Space must be allowed for the buffers used by the library routines, which go from J0075 to J0077777 (i.e. 3 blocks just below 32K).
It will be possible to alter the standard allowance, if desired. Details will be published later.
The 3 buffers are used on a free-for-all basis amongst all tapes in use.
The routines are designed to work correctly even when the number of tapes in use exceeds the number of buffers.
- The tape (or disc) number i is in the range 0 ≤ i ≤ 15. The TAPE and DISC statements may refer to either tape
or disc (wait until disc files are available!) as an actual medium.
The DISC statement specifies a starting sector or block, and writes (or reads) beginning at that position with no logical separators.
That is WRITE DISC 4, (A(J), J=1,512) would just fill one block.
The TAPE statement on the other hand requests the transfer of a further logical record beginning where the previous one ended.
Separators are written to the tape to define the length of records on the tape in the same format as the AWRE supervisor
variable length tape extracodes.
It should be possible to read tapes written by Fortran at SRC Chilton.
- The statements BACKSPACE, ENDFILE, WRITE OUTPUT TAPE etc. will soon be available.
The routines for these are currently included within the library, but they should not be used at present, as they are known to contain errors.
3. Modifications to the System Manual
- 2.2
- LOADBAS is available in the Mk.10 supervisor.
- 2.5
- Each stream number must be preceded by P or D, Not that if a non-zero stream is specified as P, and INPUT P0 FOLLOWS is required,
then it must be explicitly stated.
- Appendix 2
- add to previous corrections
1 Unassigned Extracode *+1
- Amendments
-
1. Preset Job Description
The preset job description is
INPUT P0 FOLLOWS
COMPUTING 30 SECONDS
EXECUTION 30 SECONDS
STORE 32K (S3 FORTRAN uses 40K in its phase)
OUTPUT 0 PRINTER 100 PAGES (20 PAGES IF LOADBAS)
OUTPUT 14 PRINTER 20 PAGES
OUTPUT 15 PUNCH7 5 PAGES
Any of these settings may be suppressed by actually stating the required value in the job description.
Note, however, that OUTPUT 0 PRINTER will have a limit of 53 not 100, PAGES inserted.
4. Notes on the use of ASP (see also Appendix 4 of the System Manual)
The pseudo operation COMMON must not be used as it gives rise to illegal (J3) addresses.
In addition, care must be exercised with any routines written for use at SRC Chilton to
ensure that the range of addresses used is valid.