MPE/iX System Utilities Reference Manual (32650-90908)

Chapter 30
V7FF8CNV
Operation
224
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.