30 Jun
2023
30 Jun
'23
11:21 p.m.
Ok, so I grabbed some DS/DD 3M 8" disks - I assume I can "MARK" them
(reformat). But so far no luck. I never had disks on the 5110, so still
learning about them on the 5120 - I assume they still need to be "MARK"
just like the tapes are?
Here is a short video I made of the 5120 disk drives I have during startup
of the system. I'll double check the fuses of the system tomorrow - the
fuse behind the CRT was blown, so I'm thinking it's possible this system
had some other electrical problems.
IBM 5120 Disk Drive Example (benchtop experiment) - YouTube
<https://www.youtube.com/watch?v=UxyDDx8LOGw>
https://www.youtube.com/watch?v=UxyDDx8LOGw
Much to investigate, but so many other projects - I may need to just put
away these 8" drives for a while.
OH, and I finally got to talk about the 5100 series. I'm not the best
speaker and a couple mistakes I noticed - but mostly I hope I didn't
horribly misrepresent your prior work.
https://www.youtube.com/watch?v=JIJNrBaTenM
-Steve
On Mon, Jun 19, 2023 at 3:38 AM Christian Corti via cctalk <
cctalk(a)classiccmp.org> wrote:
On Sat, 17 Jun 2023, Steve Lewis wrote:
My only question is: how "universal"
are 8" disk? This 5120 only came
with
a single IBM 8" Diagnostics disk. It looks
to be in fine condition, but
I've no idea about the data.
I can answer your question very quickly:
A 5120 is exactly the same as a 5110 plus 5114. This said, the diagnostics
and any software apply to both systems.
You can take any 5110 floppy image and recreate a real floppy from it. The
format BTW is "the" standard IBM format. The 5114/5120 can handle
everything from single-sided single-density up to double-sided
double-density. The firmware OTOH has a predefined set called "formats",
ranging from 1 to 9, with an optional suffix indicating the number of
additional directory tracks (only available with DD). The list is
somewhere in the manual, e.g. format 1 is SS/SD 128 bytes/sect. 26
sects/track, and format 8b (b=blank) is DS/DD 512 bytes/sect. 15
sects/track.
IIRC format 1-3 are SS/SD, 4-6 SS/DD and 7-9 DS/DD
Christian