[Coco] Issues with NitrOS9 build

Bob Devries devries.bob at gmail.com
Sun Jan 26 17:44:18 EST 2014


Robert,
I'm sorry but I need to disagree with you about IT.TYP bit 0. Although the 
6809 OS9 manual doesn't specifically say so, bit 0 when it is set to 1, 
denotes an 8" drive. This is documented in the OS9 version 2.4 (68K) manual.

DD.FMT is defined on page 5-16 of the OS9 Manual (original OS9)

Regards, Bob Devries
Dalby, QLD, Australia

----- Original Message ----- 
From: "Robert Gault" <robert.gault at att.net>
To: "CoCoList for Color Computer Enthusiasts" <coco at maltedmedia.com>
Sent: Monday, January 27, 2014 5:42 AM
Subject: Re: [Coco] Issues with NitrOS9 build


> Bob Devries wrote:
>> Gene,
>>
>> I'm with you on that one.
>>
>> I suggest an entry in rules.mak. That would mean just a single line 
>> change in
>> rules.mak at build time to change the value to 5.25" or 3.5".
>>
>> E.g. D80TRK=5
>> or D80TRK=3
>>
>> and based on that, the 80 track descriptors should be correctly built, 
>> and also
>> the format command will select the correct DD.FMT value for LSN0 for 
>> 5.25" or
>> 3.5" at the discretion of the user/builder.
>>
>> More thoughts anyone?
>>
>> Regards, Bob Devries
>> Dalby, QLD, Australia
>>
>
> If you look in the technical section of OS-9 Level2 you will find that 
> IT.TYP bit 0 is defined 0=5" floppy so you would expect 1=3.5" floppy. 
> ITDNS is defined as bit0 0=FM 1=MFM, bit1 0=5" 48tpi 1=5" 96tpi. It does 
> not seems to be explicitly stated but DD.FMT bit0 0=single sided 1=double 
> sided bit1 is density.
>
> NitrOS-9 has followed this convention and there is no need to change these 
> definitions. What would make sense is to decide what format we want an 
> 80-track disk to have. It seems reasonable to me that all 40-track disk 
> images be 5.25" 48tpi disks and all 80-track disk images be 3.5" 135tpi. 
> By convention in the current rbf.d file, 48tpi and 135tpi disks are both 
> assigned DNS.STD while 96 tpi is assigned DNS.DTD.
>
> ==================
> It should be clear to all, that the initial report of this problem did not 
> indicate anything about the actual hardware in use for drives. Please 
> please everyone, in future when reporting problems present enough data for 
> the problem to be solved. In this case, reporting a problem with DD.FMT 
> and not indicating the version of NitrOS-9 in use, whether actual hardware 
> or an emulator was used for testing, and what drive hardware was used made 
> it impossible to formulate any theories.
>
> Robert
>
>
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