[Coco] Coco Digest, Vol 166, Issue 36

[Arthur Flexser]

P.S.  Another caveat is that if you patched DSKCON, you'd probably create
incompatibilities with various modified versions of RSDOS that a lot of
people now use, which likely have their own conflicting modifications of
DSKCON.  I'd strongly suggest just dropping back to single speed for disk
i/o.

On Thu, Aug 25, 2016 at 5:53 AM, Arthur Flexser <flexser at fiu.edu> wrote:

> There's quite a few places that need to be patched, though for your
> purposes, you probably need to patch only the main DSKCON routine that does
> sector reads and writes.
>
> Perhaps someone here can point to a file that contains the necessary fixes.
>
> Be aware that you'd need one set of fixes for Disk Basic 1.0 and an
> entirely different set for DIsk Basic 1.1.  I don't think it's worth the
> trouble, since disk i/o speed is limited in any case by the rotational
> speed of the floppy, so gains from going to double speed for disk i/o would
> be minimal, mainly from occasionally saving an extra rotation to get the
> required sector under the drive head, which saves 0.2 seconds.  Better to
> just drop the CoCo 3 back to single speed temporarily when disk i/o is
> needed.
>
> Art
>
> On Thu, Aug 25, 2016 at 4:54 AM, Pere <psergm at gmail.com> wrote:
>
>> Hi Art,
>> I am new to the CoCo developpment arena and know just a few about the
>> CoCo3.
>> As the POKE&HFFD7,0 works well in CoCo and Dragon I thought that issuing
>> the
>> double speed for the CoCo3 would work well ... in fact the tests I have
>> done, have
>> been made on VCC, so I cannot speak about the real thing.
>> VCC supports well that double speed, the images are loaded faster without
>> problems.
>> If it were just a matter of changing (doubling) the value of a few bytes
>> to compensate
>> for the double speed, I could add these changes. Could you give me any
>> pointer to
>> know what places should be modified (for reading and writting)
>> The program calls the FREE, CLOSE and LOF commands too
>> Thanks in advance
>> pere
>>
>> -----Mensaje original----- Message: 4
>> Date: Wed, 24 Aug 2016 18:14:23 -0400
>> From: Arthur Flexser <flexser at fiu.edu>
>> To: CoCoList for Color Computer Enthusiasts <coco at maltedmedia.com>
>> Subject: Re: [Coco] The Hobbit ported to 6809 (Dragon64 and coCo2 64k)
>> Message-ID:
>> <CA+LuDcc=ZU1g6e4kaCqDcQ+Odg_qMBsf6rOM03WVTX6YwVRCbg at mail.gmail.com>
>> Content-Type: text/plain; charset=UTF-8
>>
>> This sounds like a bad idea if you are doing disk I/O at double speed.
>> The
>> CoCo 3's disk routines must be modified to do this reliably, on account of
>> insufficient delays at double speed.
>> Art
>>
>>
>> --
>> Coco mailing list
>> Coco at maltedmedia.com
>> https://pairlist5.pair.net/mailman/listinfo/coco
>>
>
>