what dual rom 128k ram memory system? very interesting! I'm interested to
learn more. might be a conflict however with REX, depending on the
details...
On Sun, Mar 24, 2019 at 10:39 PM Peter Noeth wrote:
> Group,
>
> I purchased a REX at Tandy Assembly 2018, but am just now getting around
>
Kurt, agree with everything you have said.
The odd thing is-
* using an HD disk in an DD/HD drive, and covering the hole with tape,
would seem to be BAD
---> because you are telling the drive to use the wrong current settings
for the actual disk media.
However, this is apparently the way to make
The magnetic coercivity on HD disks is different than on regular disks. It
requires more energy to lay down the tracks. If you start with a blank HD disk
rather than a pre-formatted disk then you have a better chance. That's because
once the HD tracks are laid down, you need to erase them for yo
Yeah that does sound strange. And I agree, the drive 'should' switch based on
the hole in the disk. Does it format to 720 or 1.44 when the hole is covered?
On Mon, Mar 25, 2019, at 7:37 AM, Stephen Adolph wrote:
> Kurt, agree with everything you have said.
>
> The odd thing is-
>
> * using an H
when attached to a CoCo, you get 160k.
On Mon, Mar 25, 2019 at 11:02 AM Kurt McCullum wrote:
> Yeah that does sound strange. And I agree, the drive 'should' switch based
> on the hole in the disk. Does it format to 720 or 1.44 when the hole is
> covered?
>
> On Mon, Mar 25, 2019, at 7:37 AM, Ste
The difference in coercivity between DD and HD 3.5" diskettes is actually
relatively small, ~660 vs. ~720 Oersteds, compared to the much larger 290 vs.
660 difference of 5.25" diskettes.
But the thickness of the coating is also different, HD being less than half
that of DD, and different materi
Sounds similar to the original IBM 5.25" format, single-sided, 512
bytes/sector, 8 sectors/track, 40 tracks, 250Kbps.
- Original Message -
From: Stephen Adolph
To: m...@bitchin100.com
Sent: Monday, March 25, 2019 11:54 AM
Subject: Re: [M100] question regarding floppy disks.
Thanks Mike, that must be the answer.
I notice that the formatting process for an HD disk in an HD drive on the
COCO fails after the first pass on the disk formatting run.
That must mean - reading back to verify the format is failing.
So, hole "covered" tells the drive to write at 2x the speed!
... But it's actually 256 bytes/sector, 18 sectors/track, 35 tracks ...
;-)
- Original Message -
From: Mike Stein
To: m...@bitchin100.com
Sent: Monday, March 25, 2019 12:28 PM
Subject: Re: [M100] question regarding floppy disks.
Sounds similar to the original IBM 5.25" for
> So, hole "covered" tells the drive to write at 2x the speed! Interesting,
> and makes sense.
Well, no, hole "covered" signals 250Kbps low write current DD so if anything
it's the other way around (unless my aging brain is even more confused than
usual).
But I think the actual data rate is
yes, I wrote that backwards. but thanks I feel like I got all my questions
sorted.
On Mon, Mar 25, 2019 at 12:58 PM Mike Stein wrote:
> > So, hole "covered" tells the drive to write at 2x the speed!
> Interesting, and makes sense.
>
> Well, no, hole "covered" signals 250Kbps low write current
Steven,
The Dual ROM/ 128k RAM Memory system is of my own design. Basically the
standard ROM / RAM was removed and replaced with a new daughter board. It
allows selecting RAM in 32k banks (4) and system ROM by using the BASIC OUT
x,y statement. I had this in my T102 for about 2 years before I go
Wow very nice.
That makes great sense. I misinterpreted the "rom" statement. I thought
'option ROM'... not main rom.
very cool.
On Mon, Mar 25, 2019 at 6:31 PM Peter Noeth wrote:
> Steven,
>
> The Dual ROM/ 128k RAM Memory system is of my own design. Basically the
> standard ROM / RAM was rem
Peter did you worry about power up flip flop state?
If So what is the circuit you used? Thx.
On Monday, March 25, 2019, Peter Noeth wrote:
> Steven,
>
> The Dual ROM/ 128k RAM Memory system is of my own design. Basically the
> standard ROM / RAM was removed and replaced with a new daughter
I've been thinking about a 2MB RAM option ROM replacement, which would yield 64
pages of either RAM images or paged file space; I suppose I could add an
alternate system ROM while I'm at it ;-)
m
- Original Message -
From: Stephen Adolph
To: m...@bitchin100.com
Sent: Monday, M
I don't suppose you could just power it from Vb so it retains its settings
unless specifically reset?
- Original Message -
From: Stephen Adolph
To: m...@bitchin100.com
Sent: Monday, March 25, 2019 8:06 PM
Subject: Re: [M100] REX: Downloading OPTROM images
Peter did you wor
I was just reading the REX Manager User Guide (
http://bitchin100.com/wiki/index.php?title=REX_Manager_User_Guide) and
found that the screen shot seems quite out of date (v4.5). Although the
operation described seemed to match the current version (v4.9), it does not
explain what the "reverse vide
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