268Re: Hi & a question
- Feb 7, 2003Welcome to the group.
I haven't heard of any designs for using 3" drives. The Altair
software and hardware was all designed around "hard-sectored"
diskettes, and that may prove to be the biggest problem. I have
never seen a hard-sectored 3" diskette- only soft-sectored.
Of course, there were many other S-100 systems that did use soft
sectoring, It might be a fairly simple task to do some timing
changes on one of those old controllers for use with 3" disks. I
don't know the rotational speed of 3" drives, but I think 8" and 5"
ran at 360 and 300 RPM. Whatever the speeds, though, you would have
to compensate for rotational speed differences by making timing
changes to the circuits that generate the sector and byte timing. I
could be full of beans here, but this approach doesn't immediately
seem like it would be a major task. What do you other members think
Done this simply, you wouldn't be able to use the 3" to its full
1.4MB capacity. You would still only use as many tracks as the
original system, and as many bytes per track as the original system,
and most likely only one side of each disk. There would be a lot of
wasted potential, but at least you would be using "state-of-the-art"
diskettes and drives (or maybe not so state-of-the-art. I just read
that Dell will discontinue installing floppies on most future systems
in favor of CDs). I recall that an 8" floppy back then held 320 to
360 KB on about 80 tracks. I think 5" floppies held about half that
much data per side on half as many tracks. It's been a long time,
so don't take any of my numbers too literally, but I think I'm in the
right ball park.
What I would like to see is a CD burner that could be used in an
Altair system, using Altair BASIC, that looked to the system like its
own hard drive or floppy drive (now THERE'S a waste of space). All
of that old software is rotting away on 25 year old diskettes and
really needs to be archived on the more permanent CD medium. If you
ever see anything like that, please tell us about it.
I look forward to seeing your pictures.
--- In email@example.com, "Larry Troth" <larry@u...>
> Hellosome new
> I have just joined the group and I am looking forward to gaining
> knowledge regarding the old hardware that I have. After 20+ yearsin
> storage, I will finally be able to get my s-100 systems (yes, I haveand info.
> several) bake in operation. As I get them up I'll post pictures
>While I have
> My question is about some new hardware for these old systems.
> a good supply of 8" floppy drives and floppies, it is only a matterof time
> till the last of them give up the ghost. Has anyone come up with adiskette
> kit/board/schematic/??? to allow the use of the new 1.44Mb 3-1/2"
> drives with these old systems? I would love to transfer my olddata from
> the 8" media to the 3-1/2" media. Does anyone know of any webpages that
> discuss this? Are there any resources out there? (I found a sitethat has
> a new card for the SWTP 680 systems to do this, so what about he s-100
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