Re: [midatlanticretro] building new vintage hardware (was 680..)
- oh, I still have about 20 sockets left to replace, it's such an arduous
task. Something I do in between my other projects. I'm hoping that I'll
get it done once the S-100 boards I'm designing are built.
In the meantime, I'm going to fire-up my IMSAI, (figuratively speaking)
so I can get my S-100 stuff running and be ready to test the new memory
[ My Corner of Cyberspace http://ragooman.home.comcast.net/ ]
B Degnan wrote:
> Did you get your Altair 680 working?
- David Comley <david_comley@...> wrote:
>There was a recent discussion of MFM "emulation" in comp.os.cpm, where
> I'm hoping to be able to emulate a Micropolis 1325 at
> a low enough level that it could support any
> host/controller platform (that can use that particular
> drive type/geometry etc). The drive emulation should
> be transparent to the point where any low level format
> can be overlaid on it by the controller or host.
> Doing an emulation of an MFM drive would be useful for
> a variety of reasons for hobbyists, not the least of
> which is the cost of replacement drives. The MTTF of
> the platters in these drives is 4 years so they are a
> dying breed; plus, emulation would make it possible to
> expose the low-level formatting used by the hardware
> vendor, something that there's not a great deal of
> documentation on so far as I can tell.
> Of course talking about it is easier than actually
> doing it...
I participate. The discussion of "vintage" vs. "modern" design is also
of interest to me. Here's my comments.
In comp.os.cpm, it was noted that there WAS a MFM to IDE product, but
it waa a few thousand dollars. Seems to me that one reason it is that
high, is that it takes some bit of effort to support the variety of
potential uses for such a product. Those who really need an MFM
replacement, to keep production equipment going, will pay accordingly.
The drive issue as cast in comp.os.cpm was about replacing an MFM
drive in a S-100 system. It was suggested the owner use an IDE card of
some sort, and write a driver. In some number of cases, it's more
reasonable to replace the controller and adjust the software.
The point of S-100 systems with a standard bus, was that you COULD
replace and upgrade as needed. At least the hardware did not stop you
from doing so. That concept spawned a computer industry from 1976
through the 1980's. The IBM PC, to compete, HAD to offer 1) a bus and
2) clear means to add to that bus - because S-100 and other systems
set that standard. (In the minicomputer world, DEC set a similar
standard as did other manufacturers.)
In that light, there's been discussion here about building "new" S-100
cards with either "vintage" hardware or with "new" hardware. Clearly
an MFM to IDE device would be "new". It would require somewhat fast
logic: either a programmable logic device, or a "computer on a
But an IDE interface for S-100 or any Z80? - dirt simple, the IDE
drive does all the work, just a few simple chips will do it (Google
"GIDE"). But most people get stuck at the point where they have to
write software to support that new device. (I should know, I first
offered the GIDE interface in the USA, and I've watched its use.)
Note to "purists" that say a vintage system has to have "original",
vintage cards. Few REAL S-100 systems were "original", or stayed
original. People upgraded as hardware improved, as software changed.
The point? As I see it, if you are "into" old computers to show them
off in original condiiton, then all this talk about "emulators" is
moot. Pay $$$ for the last unused (or rebuilt) MFM hard drive and run
it only on exhibit day. If you are in it because you can "dig into"
it, then adapt some new hardware to old and start writing some CODE.
If you are in it for "use" only, then you depend on others to keep
providing working hardware: that, and your budget.
Herbert R. Johnson, New Jersey USA
<a href="http://www.retrotechnology.com/herbs_stuff/"> web site</a>
<a href="http://www.retrotechnology.net/herbs_stuff/"> domain mirror</a>
my email address: hjohnson AAT retrotechnology DOTT com
if no reply, try in a few days: herbjohnson ATT comcast DOTT net
"Herb's Stuff": old Mac, SGI, 8-inch floppy drives
S-100 IMSAI Altair computers, docs, by "Dr. S-100"
- Well said, Herb.
Having met so many MARCH folks at TCF, I started to
think again about my own take on the hobby. I'd
profile my own collection and activities as being
discovery - or re-discovery - related, rather than
restoration/refurbishment to original condition. Most
of the things I've acquired are missing covers or have
dings and dents, and nothing could be said to be 'New
in Box' or even close. Instead, I spend a lot of time
trying to understand how things were connected or
configured together (and even what they were used
for). That often results in repair work to return a
system to a bootable state (or in a long wait while I
scour hamfests and swap meets to find a missing board,
cable or disk).
It's a great hobby, isn't it: each of us derives
satisfaction from it from pursuing a different aspect
or perspective - and hopefully we contribute to a
broader pool of knowledge by doing so. One can only
hope that we capture that knowledge somehow for
posterity and the next generation of enthusiasts.
--- Herb Johnson <hjohnson@...> wrote:
> Note to "purists" that say a vintage system has to
> have "original",
> vintage cards. Few REAL S-100 systems were
> "original", or stayed
> original. People upgraded as hardware improved, as
> software changed.
> The point? As I see it, if you are "into" old
> computers to show them
> off in original condiiton, then all this talk about
> "emulators" is
> moot. Pay $$$ for the last unused (or rebuilt) MFM
> hard drive and run
> it only on exhibit day. If you are in it because you
> can "dig into"
> it, then adapt some new hardware to old and start
> writing some CODE.
> If you are in it for "use" only, then you depend on
> others to keep
> providing working hardware: that, and your budget.
> Herb Johnson