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
I have an ST-251 42MB MFM hard disk drive.
The documentation says the drive is 512 bytes per sector. I don't know
if this is fixed (hard sectored) or not.
My problem is my operating system (OS/9 Level II) wants 256 bytes per
sector. The OMTI 20C-1 controller can handle that but I'm not sure if
the ST-251 can.
Does anyone know if the ST-251 can support 256 bytes per sector and/or
how to configure it for 256 bytes per sector?
Thank you,
Mike
I'm looking for ancient versions of the VAX Workstation Software (VWS) for
my software collection and for my VAXstation I:
- V1.0
- V1.1
- V2.0
- V3.0
V1.0 (which was called "uVMS VAXstation I graphics/windowing softwarere"
back then) and V1.1 are the most wanted ones, because they are the only
ones that run on MicroVMS V4.0 for the VAXstation I.
Version 1.0 was shipped on two RX50s, labeled “VSI010 1/2” and “VSI010
2/2”; later versions grew bigger and from V2.0 onwards TK50s were used
besides RX50 floppies as well.
Best Regards,
Ulli
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 🙂
Via one of the articles about that Unix V4 tape I found this https://eylenburg.github.io/os_familytree.htm which is quite an impressive chart of operating systems old and new.
A few bits are clearly incorrect or missing; for example, P/OS and TRAX are both not there. I was going to mention them to the author of that chart but I don't actually know the correct placement. (Is P/OS an RSX-11/M or M+ derivative? I should know but don't.)
Neat to see RSX-15 mentioned as the ancestor of RSX-11/D. Did the earlier RSX-11 versions ever ship? I know I have seen traces of /A and/or /C...
The DOS-11 and RSTS entries aren't quite right either, I can send feedback for those.
Also, while VMS is reasonably listed as RSX-11/M derivative, I always thought that VAXElan was unrelated. Along the same lines, where would MicroPower/Pascal fit?
paul
As many have heard, COMPUTE!'s GAZETTE magazine has been resurrected as of
this past July 2025. And its fifth issue for November is just days away.
I'm not sure if attachments are working here, but there should be a catalog
summary of the article titles (for those who aren't subscribed but were
curious to browse the kinds of things being covered).
That same summary catalog is also archived here:
https://github.com/voidstar78/GC_TOC_SUM_CAT/blob/main/CG_2025_TSC_V0_1.TXT
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
