| Title: | VAX on VMEbus: KAV30 |
| Notice: | Could have been as fast as 68K but its a VAX! |
| Moderator: | CSSVMS::KAV30_SUPP |
| Created: | Thu Apr 18 1991 |
| Last Modified: | Fri Aug 02 1996 |
| Last Successful Update: | Fri Jun 06 1997 |
| Number of topics: | 159 |
| Total number of notes: | 645 |
A customer gets a problem while using a WORD BOOLEAN variable on a
KAV30 compatible board. The customer uses Epascal.
In his program he can assign this variable to TRUE without problem but
when he tests it he states that the byte tested is the MSB byte. This
looks like a Big-Endian <-> Little-Endian conversion (swap) problem
with this kind of used board.
Is somebody aware of a such problem and knows a solution (declare a
dummy byte after the used variable?) ??
Thanks for help.
Jean-Pierre
| T.R | Title | User | Personal Name | Date | Lines |
|---|---|---|---|---|---|
| 75.1 | Double-mapping is one possibility | EICMFG::BURKE | Jim Burke, @UFC | Thu Feb 11 1993 10:18 | 10 |
Jean-Pierre,
I came across a similar problem when writing the VDAD Driver [this
is included in the KAV Toolkit].
How I got round it, was to do TWO mappings - one with byte swapping
(for word access) and one without swapping (for byte access). Remember
that I was accessing the same (shared) memory area with the two
mappings. Have a look at the VDAD initialisation section of the code.
Jim
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| 75.2 | Thanks | SWTHOM::COSTEUX | The Present is already the Past | Thu Feb 11 1993 15:17 | 6 |
Jim,
Thanks for this info. This could be the solution against the customer's
problem. I'll this workaround to him.
Best regards,
Jean-Pierre
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