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BSP$-Program File Basic Service Package
The following are considerations when reading or initializing the program file FTI with the
RFTI$ or RFTI$$ functions (see 5.1.1):
• Calling programs that use the RFTI$ function will not recognize existing LEPFs and
cannot initialize an empty file as an LEPF. These programs must be modified to use
the RFTI$$ function to read the FTI.
• Calling programs that use the RFTI$$ function must be modified to specify the new
parameter, BSP$ interface level, in register A1, H1. A value of 1 is required to
recognize existing LEPFs and to initialize an empty file as an LEPF.
• The parameter specified in register A2 is ignored if the file is an existing program file.
• On a normal return, the value in register A1 describes the basic program file
characteristics of the file that was read or initialized. Bit 29 of A1 is clear if this file is
a PF or LPF; bit 29 of A1 is set if this file is an LEPF. The calling program should
save the A1 return value so that the contents of existing element table entries can
be correctly interpreted and so that new element table entries can be correctly
formatted.
To correctly interpret the length of element text when reading element table entries with
the ETIS$ function (see 5.1.3) or the ETNL$ function (see 5.1.5), the following need to be
considered:
• When reading elements from a PF or LPF:
− The maximum element text size is 262,143 sectors.
− The element text length in word 7 is stated in sectors for all element types.
− For all element types, the flag bits field, element-text-length granularity (word 3,
bits 1 and 2) is not used and should be ignored.
− For symbolic elements, element-text-length word 7, bits 6 through 17 (S2 and
S3) are not used and should be ignored.
− For omnibus elements, element-text-length word 7, bits 12 through 17 (S3) are
not used and should be ignored.
• When reading elements from an LEPF:
− The maximum element text size is limited only by maximum file size. The
theoretical maximum is 07777764400 or 1,073,735,936 sectors. This is based
on the maximum possible file size minus 1,792 sectors reserved for the TOC of
a standard LEPF.
− Make sure the correct field size is used when loading element-text length from
word 7. For symbolic elements the field size is 30 bits (bits 6 through 35) and
for omnibus elements the field size is 24 bits (bits 12 through 35).
− Once the correct element-text-length value is loaded, the element-text-length
granularity field (word 3, bits 1 and 2) must be examined:
ο If it is 0, element text length is stated in sectors.
ο If it is 1, element text length is stated in tracks. Track granularity can be
converted to sector granularity by multiplying by 64 or by shifting left by 6
bits.
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