[fpc-devel] On a port of Free Pascal to the IBM 370

[Hans-Peter Diettrich]

>> ? It just means you must convert ascii to ebcdic in OS calls that require
>> strings. All these calls must be re-implemented anyway, so a generic
>> routine
>> to do this conversion seems like the obvious path. I doubt this will be
>> the
>> real bottleneck :-)
> 
> It should not be a bottleneck, but I'm afraid that you underestimate it a
> bit.

IMO the only bottleneck could be the availability of 8 bit bytes 
(dunno). At least I remember mainframes with byte sizes of 6..16 bits. 
When at least 8 bits are available, then a program can use 
ASCII/ANSI/UTF-8 internally, and strings have to be converted into 
EBCDIC in system calls, like they have to be converted for every OS with 
specific character sets or encodings.

It would be a real challenge to adopt FPC and all ordinal type handling 
(and pointers!) to a different byte size. E.g. DG machines only can 
address 16 bit words, so that access to 8 bit entities requires explicit 
machine code, and PByte or PChar is very tricky to implement. On such 
machines UTF-16 would be a good choice for the native string type.

DoDi