Path: csiph.com!v102.xanadu-bbs.net!xanadu-bbs.net!feeder.erje.net!eu.feeder.erje.net!news.swapon.de!eternal-september.org!feeder.eternal-september.org!mx02.eternal-september.org!.POSTED!not-for-mail
From: Raymond Wiker <rwiker@gmail.com>
Newsgroups: comp.sys.apple2
Subject: Re: Brutal Deluxe Software releases Merlin 32
Date: Sun, 01 Feb 2015 15:54:38 +0100
Organization: A noiseless patient Spider
Lines: 39
Message-ID: <m2d25tfzrl.fsf@gmail.com>
References: <02ec2596-dc67-4b67-a524-958e6dce6150@googlegroups.com> <c8bb4579-8904-4861-aa4b-9d5958f44cbb@googlegroups.com> <mmphosis-1420756952@macgui.com> <m3mw5seiqu.fsf@gmail.com> <alpine.DEB.2.02.1501090334180.69114@localhost> <mmphosis-1420785555@macgui.com> <mmphosis-1420801113@macgui.com> <da939b58-efd1-4f20-85fc-5df27c1cfe8d@googlegroups.com> <m24mrxac5p.fsf@gmail.com> <m8uuu3$691$1@speranza.aioe.org> <cfd2f23f-522b-4863-b0a0-44d4f52f468d@googlegroups.com> <D0EE5DAF.2D0A0%hughhood@earthlink.net> <6fe10e83-0250-49eb-92eb-93afe530782c@googlegroups.com> <D0F2868D.10967%hughhood@earthlink.net> <D0F33AB5.1096E%hughhood@earthlink.net> <K7qdndY4Avjtq1PJnZ2dnUU7-IGdnZ2d@giganews.com>
Mime-Version: 1.0
Content-Type: text/plain
Injection-Info: mx02.eternal-september.org; posting-host="6795c6b5efa8fe68018748717e86deed"; logging-data="8565"; mail-complaints-to="abuse@eternal-september.org";	posting-account="U2FsdGVkX18ASoA/xM5vNO6MTg3OMf2l"
User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.4 (darwin)
Cancel-Lock: sha1:jvOMeT+EUWZov7l7tYCp886XimY= sha1:kAt/Cf9VilKdnty7oRj3dD3JVKE=
Xref: csiph.com comp.sys.apple2:23774

Steven Hirsch <snhirsch@gmail.com> writes:

> On 02/01/2015 03:06 AM, Hugh Hood wrote:
>
>> I managed to cobble together enough PPC support in your Merlin 32 to satisfy
>> my 8-bit assembly requirements, so please don't make PPC support a priority,
>> unless you have others requesting it.
>>
>> For anyone else who is interested in building Merlin 32 on a PPC (and whose
>> needs are as simple as mine), look in Olivier's a65816_Data.c file. Starting
>> at line #447, he has a series of (12) statements that handle the Merlin data
>> pseudo ops DW, DA, DFB, DB, DDB, ADR & ADRL.
>>
>> For example, here is line #447:
>>
>> current_line->data[2*nb_valid_element+0] = data[0];
>>
>> As one method to fix the PPC 'endian' issue, change the instances of data[x]
>> as follows:
>>
>>   data[0] to data [3]
>>   data[1] to data [2]
>>   data[2] to data [1]
>>   data[3] to data [0]
>>
>>
>> This swaps the order of the (4) 8-bit bytes in the 32-bit integer containing
>> the data, and fixes the problem I was seeing on PPC, which is big-endian.
>
> Disclaimer:  I haven't looked at the code, but based on my own
> development experience with cross-platform interoperability it sounds
> like some carefully crafted macros might be helpful.

htonl and htons might be useful here: they turn native longs and short
into "network byte order". Unfortunately, this is the same as
big-endian, which is the opposite of what is required for the
6502. Still, you might implement something similar, like htoll (host to
long little-endian) and htosl (host to short little-endian).