MPE/iX System Utilities Reference Manual (32650-90882)

234 Chapter30
V7FF8CNV
Operation
Alternate Character Sets
Hewlett-Packard block mode terminals, which have the capability of handling all or part of
ROMAN8, can be divided into two groups. The group differentiation is based on how they
handle alternate character sets when configured for 8-bit operation.
Files using alternate character sets on one group of terminals will not display correctly on
the terminals of the other group, even when terminals from both groups are configured for
8-bit operation.
The use of characters from an alternate set affects the conversion procedure. If the forms
file does contain characters from an alternate character set, choose one of the following
alternatives:
• Eliminate the use of alternate character sets (either with FORMSPEC or while running
V7FF8CNV).
• Define alternate character sets to appear correctly on Group 1 terminals. This happens
automatically when V7FF8CNV is run from a Group 1 terminal. Characters from these
alternate sets will appear as USASCII characters on a Group 2 terminal.
Group 1 - HP 2392A, 2625A, 2627A, 2628A, 2700, and 150
Use shift-out and shift-in characters to switch back and forth between an 8-bit base
character set and an 8-bit alternate character set. This is standard for new
Hewlett-Packard terminals and printers.
Group 2 - HP 2622A, 2623A, 2626A, and 2382A
(Do not use an HP 2624A or HP 2624B, as they are unable to handle 8-bit characters
properly.) Group Two terminals use the eighth bit to switch back and forth between a 7-bit
base character set and a 7-bit alternate character set. It is not possible to get true 8-bit
operation (ROMAN8) and use an alternate character set (for example, Line Draw) at the
same time because the base character set is not really 8-bit, but 7-bit with the additional
characters defined in the alternate character set. Using both 8-bit ROMAN8 characters
and Line Draw in the same file is not recommended since the user must continually
redefine the alternate character set, switching back and forth between Roman Extension
and the line drawing character set. Shift-out and shift-in are ignored by the terminal and
return to the alternate character set when the high-order bit is on.