In the golden age of the floppy before its downfall caused by CD-R, CD-RW
and flash USB a number of new technologies were introduced to allow for
cheap removable storage (Yes MO drives existed but they were expensive).
Many of the tech were a great step forward. For example the LS-240 drives
from Panasonic/3M (Imation) allowed reading and writing to 120MB, 240MB,
1.44MB, and 720KB disks. They were also compatible with weird formats like
IBM's XDF and even allowed the storage of 32MB on a standard 1.44MB floppy
disk. To be backwards compatible they used a separate read/write head for
regular floppies. However, none of the formats with backward compatibility
read or wrote to 2.88MB ED disks.
Anybody know why? Was it a licensing issue or the perception that ED
compatibility wasn't really required or desired? Or was it technical? I am
not sure if ED drives already made use of two read/write heads (one for
720/1.44 and one for 2.88) or just one? If it is the former one could see
how it would be hard to have three separate read/write heads in one unit...
On a separate note: was a TD (Triple Density) drive ever produced?
Apparently the technology existed all the way back in 1989 and would have
give 12.5MB on a standard physical sized (3.5") floppy:
https://www-computerwoche-de.translate.goog/a/hitachi-maxell-bietet-nec-neue
-12-5-mb-floppy-an,1155888?_x_tr_sl=de&_x_tr_tl=en&_x_tr_hl=en&_x_tr_pto=wap
p (original in German)
-Ali
Hi,
Has anyone been successful in communicating using cu or some
other method to transfer files between two SIMS running Unix V ?
If so I would appreciate some help.
Thanks,
Ken
--
WWL 📚
Looking for MCM68764 and I could probably use some TMS2532 as well.
I'm also always on the lookout for blank bipolar proms (chips stargin
with 82S, and compatables).
Anyone have any of these they don't need. New, used, needing erasing,
doesn't matter.
If you have any, let me know how many you have (of each if you have
both type) and what you are looking to get for them.
If you need more standard/bigger EPROMs, I can trade too.... have a
number of 2764, 27256, have some 27128 I think too, and maybe some 27512
?
I'd have to go digging.
Thanks,
-- Curt
I have 2 Sbus Expansion chassis, one Sun, and one Integrix (IIRC). I
have the expansion chassis and the sbus controllers, but on both cases I
do not have the cables.
By looking at it, I believe they probably both use the same cable.
Anyone out there have one or two cables to spare ?
Thanks,
-- Curt
I've come across three original QIC tapes for the IBM 5100. DC300 I think,
original IBM labels.
They are in fair condition (the tape material itself seems fine, they are
all on their reels), but the "rubbers" used to actually actuate the reels
is degraded. I came across an article once on how to restore those (I
think it involved gluing the rubber band directly to the ends of the media?)
The three tapes are labeled as follows:
5721-XM3
THE IBM 5100 PROBLEM SOLVER LIBRARY
TAPE PART NO. 1608361
E.C. NO 829643 DATE 7/29/76
(this one is in a form fitted sealed ziploc-like bag, which I haven't
opened; the early magazine ads for the 5100 reference this solver library
-- I assume it is a mix of BASIC and APL)
5721-EAB
THE IBM 5100 BASIC COMPUTER AIDED INSTRUCTION
TAPE PART NO. 1608376
E.C. NO 829482 DATE 11/13/75
VERSION 1 MOD 0 FEAT 9021
PROGRAM NO. 5721-EAB CARTRIDGE 3 OF 3
(what does FEAT mean? and sadly, I don't have cartridge 1 or 2, but I
assume this is probably some BASIC code that runs some kind of tutorial
about the system)
TAPE PART NO. 1608705
E.C. NO 829637 DATE 1/10/77
DIAGNOSTIC CARTRIDGE. DO NOT ALTER THE
CONTENTS OF THIS TAPE.
(I believe when accessing the built in DCP, it has options to load and run
additional diagnostics that would be contained on this tape -- I think
"IMF" stuff, so it would be in native PALM machine code)
Anyone interested in a restoration or any contacts to folks who have worked
on QIC tape before? I have a working IBM 5100 (with working internal tape
and external 5106), but I absolutely haven't tried to insert or use these
tapes, and I have 0 experience in trying to extract data from raw media.
I don't mind shipping them off to an expert - such as anyone who maybe can
copy the data content to a new tape? (which I know is probably some
specialized equipment - I probably can't self fund that, but I am
interested to know what the options here might be)
-Steve / v*
I have the following 2 books available for the taking:
VAX architecture Reference Manuals-1987
Version 4.4 VAX/VMS Internals & Data Structures
Email tpisek at pobox dot com
Fortran question for Unix System-5 r3.
When executing fortran programs requiring "input" the screen will
show a blank screen. After entering input anyway the program
completes under Unix System V *r3*.
When the same program is compiled under Unix System V *r1* it
works as expected. The user sees the prompt.
Sounds like on Unix System V *r3* the output buffer is not being flushed.
I tried re-compiling F77. No help. Is it possible to check the runtime
libraries to see if fflush is missing?
Fortran program follows:
PROGRAM EASTER
INTEGER YEAR,METCYC,CENTRY,ERROR1,ERROR2,DAY
INTEGER EPACT,LUNA
C A PROGRAM TO CALCULATE THE DATE OF EASTER
PRINT '(A)',' INPUT THE YEAR FOR WHICH EASTER'
PRINT '(A)',' IS TO BE CALCULATED'
PRINT '(A)',' ENTER THE WHOLE YEAR, E.G. 1978 '
READ '(A)',YEAR
C CALCULATING THE YEAR IN THE 19 YEAR METONIC CYCLE-METCYC
METCYC = MOD(YEAR,19)+1
IF(YEAR.LE.1582)THEN
DAY = (5*YEAR)/4
EPACT = MOD(11*METCYC-4,30)+1
ELSE
C CALCULATING THE CENTURY-CENTRY
CENTRY = (YEAR/100)+1
C ACCOUNTING FOR ARITHMETIC INACCURACIES
C IGNORES LEAP YEARS ETC.
ERROR1 = (3*CENTRY/4)-12
ERROR2 = ((8*CENTRY+5)/25)-5
C LOCATING SUNDAY
DAY = (5*YEAR/4)-ERROR1-10
C LOCATING THE EPACT(FULL MOON)
EPACT = MOD(11*METCYC+20+ERROR2-ERROR1,30)
IF(EPACT.LT.0)EPACT=30+EPACT
IF((EPACT.EQ.25.AND.METCYC.GT.11).OR.EPACT.EQ.24)THEN
EPACT=EPACT+1
ENDIF
ENDIF
C FINDING THE FULL MOON
LUNA=44-EPACT
IF(LUNA.LT.21)THEN
LUNA=LUNA+30
ENDIF
C LOCATING EASTER SUNDAY
LUNA=LUNA+7-(MOD(DAY+LUNA,7))
C LOCATING THE CORRECT MONTH
IF(LUNA.GT.31)THEN
LUNA = LUNA - 31
PRINT '(A)',' FOR THE YEAR ',YEAR
PRINT '(A)',' EASTER FALLS ON APRIL ',LUNA
ELSE
PRINT '(A)',' FOR THE YEAR ',YEAR
PRINT '(A)',' EASTER FALLS ON MARCH ',LUNA
ENDIF
END
Any help would be appreciated,
Ken
--
WWL 📚
Legendary discoverer of Moore's Law Gordon Moore passed away. Whether it
truly is a 'law' is debatable but its effect on microprocessor development
is hard to deny. Our industry/hobby or interest was built on a technology
G. Moore helped to develop.
Happy computing!
Murray 🙂
Another recent acquisition is for all your handheld calculator enthusiasts.
From 1975 here is “How To Entertain With Your Pocket Calculator”
Click to:
https://archive.org/details/htewypc
Michael.
--
*Blog: RetroRetrospective – Fun today with yesterday's gear……..
<http://www.jongleur.co.uk/blogs/>*
*Podcast*: *Retro Computing Roundtable <http://rcrpodcast.com/>* (Co-Host)
