There have been a few versions of the utility imd2raw.c floating around
that will take Dave Dunfield's ImageDisk-created images (i.e. an .IMD file)
and make a linear binary image devoid of any metadata. This is similar to
the function of Dave's IMDU.COM program's /b switch.
I've corrected a problem with the assumption that all imd2raw.c descendants
to date have made: sectors that have a skew (i.e. not 1-1 interleaved)
weren't linearized correctly. The skewed sectors need to be written out in
"sorted" order, which is not necessarily captured/physical order. This is
easily verified by comparing output from "IMDU /b" to earlier imd2raw
outputs on any .IMD that has a sector skew that isn't 1, 2, 3 [...].
It's up on github here:
https://github.com/RetroFloppy/imd2raw
Hello,
I'm an employee with the National radio astronomy observatory here in Socorro New Mexico.
As part of our NGVLA upgrades, we are seeking to get rid of old data tapes from the tape reel days of Computing. These contain things such as the boot loaders, OS, specific collection programs and antenna movement programs.
I personally would hate to see these just wind up in the literal dumpster and would like to see them sent out to a museum or an archiving body that can preserve them and keep them safe as a dynamic part of history.
If anyone is interested or knows someone who would be interested in the VLAs data tape library please let me know.
V/R
Danielle Werts
Front end engineer
VLA Socorro New Mexico
Hi everyone,
According to historians, and I consider myself one, let us consider what
classic/vintage computers were: The 1970s saw the three amigos: Apple II,
TRS-80 and Commodore PET and the OS was DOS and its ilk + CP/M. The 1980’s
saw the Dells, HPs and many others with MS-DOS & IBM PC-DOS from QDOS. We
saw this and behold ’bring on the clones’(I just had to say this!) The era
of old computers saw one generation building on the shoulders of giants who
designed these wayback computers(with apologies to Wayback Machine).
Today’s PCs and ARM machines are just the latest iteration of this
theory(by the way not mine).
Happy computing
Murray 🙂
It seems that nowadays you can't get *any* replacement for failing DEC
3639 aka 2N3639 transistors. All parts are obsolete and unobtanium, e.g.
2N3640, PN3640, MMBT3640 and so on.
So, what can be used instead? The most important electrical parameter is
the storage time. It needs to be *very* low, around 20-30 ns.
Does it mean that a failing PDP-8 will stay a dead PDP-8 from now on?
Christian
40 years ago this year Intel came out with the 80386 – 386 – or i386.
Either seems to be correct. What this meant was a memory address of 4GB,
far beyond what an average computer user would need or want, but was so
much more than previously(8086, 80286); ‘true’ multi-tasking which for the
average computer user didn’t mean all that much; and paging, which made
virtualization possible- experimenters were over-joyed! What all this
contributed to was the end of the classical/vintage-computing era. Whether
this began the time of open-source OS development is debatable!
Happy computing?
Murray 🙂
I am looking for the assembler listing for a bootloader for booting from
MSCP disks like RD-disks.
Google has not been very helpful and my assembler knowledge is not enough
for me to write one from scratch. Does anyone have one they can share?
- Peter
We may have a half a dozen DECtapes, probably from the PDP-6 era,
perhaps with ITS with content...
Is there anyone, preferably in the MIT vicinity, who might have a
working DECtape drive and be willing to try to read the tapes?
Thanks
/guy fedorkow
Can someone tell me the frequency of the R405 module in slot PF36 for the
EAE of the classic PDP-8? Should it be the same as the R405 processor
clock?
Christian
