Cool - I've been watching tcpdump on the Linux box, so I'm seeing the
I'll spare everybody and ask that people send me email (directly) only
if they see a problem. I'm going to comb through the logs from the DOS
box and the tcpdump when all is done to see if I missed any corner cases
in the protocol.
Straight TCP/IP is pretty fun to do. Getting the error handling down is
not as easy. I'm also missing a few functions:
- I'm not honoring the receive window from the other side.
- I'm not detecting or cleaning up half-open connections.
- I don't have a really robust algorithm for measuring round trip packet
time and determining a timeout period. (I'm just defaulting to 10 secs ..)
All of this will get fixed, but I was so desperate after a year of work
to see this code do something. :-)
I recently dug out an IBM XT to create some 5.25 floppy images and
while I'm at it I thought I'd try to get the Plus Hardcard 20
installed it it working. (This is a dual floppy XT without an
original IBM hard drive).
Does anyone know how to low-level format the Plus Hardcard 20? There
is ROM data at C800:0, but it doesn't look like g=C8000:5 would
execute valid code so I don't think that is the trick with this drive.
I searched the net for while but came up empty for useful info.
> Ohhh - nice big power hungry ECL based Classic 3000! Really slow
> compared to later PA-RISC cousins, but a nice machine. Pair this with a
> Stan Seiler might have some additional color. I was working in the RTE
(Sieler: i before e)
The HP 3000/64, /68, and /70 were nice, big machines. My company still
has a client running an HP 3000/70 ... they claim they've twice tried
to migrate to a newer (PA-RISC based) HP 3000, but that each time the
migration "failed" (no one there now remembers anything about the failures :)
They're running it with the clock set back 28 years to avoid Y2K problems.
The 3000/64 was interesting. IIRC, it could have about 8 MB of RAM (based
on both marketing and operating system limitations), but the backplane had
enough wires/signals that it could really support something like 128 MB.
So, when we created the RAM disk for it (with Kelly Computer Systems),
we were able to stick in something like up to seven 16 MB boards for a large
(in those days) RAM disk. We were disappointed to see that the /68 and /70
reduced the backplane's ability to talk to memory down to 32 MB ... so
we changed our RAM disk to use bank switching. I remember being amused
because the engineer who was tasked with making the board design changes was
a nice guy named Lim (#1).
We got a surprising bump in orders during the buildup to the first Gulf War,
because the Navy used a lot of 3000/70s and needed to speed up processing
(and they chose to use our RAM disk).
#1: LIM = Lotus-Intel-Microsoft, the guys who "invented" bank switching for
the IBM PC sometime after it was already on the market from Tall Tree Systems.
sieler at allegro.comwww.allegro.com/sieler/wanted/index.html
At 5:09 -0600 12/24/06, Patrick Finnegan wrote:
>A new mainframe. :)
>Happy holidays to all!
notes, down at the bottom, that my 68k NeXT cube  is just about,
finally, after many years of trying, to crunch enough OGR-25 units to
surpass the total done by S/390's (under Linux).
Sure hope Pat keeps that beauty (for which, let me add my
congratulations!) on its original OS....
Happy New Year to all!
 I *think* I have the only 68k NeXT contributing to that project...
Mark Tapley, Dwarf Engineer
(I haven't cleared my neighborhood)
210-379-4635 Dwarf Phone, 210-522-6025 Office Phone
> Something else to think about is that he can claim copywrite on the
> compilation of those scans, thereby preventing you from posting *HIS*
> scans, so just do yours at a higher resolution :^)
I'm not sure you can claim copyright on a collection
of copyright violations :)
With the evil copyright laws, I suspect that the originals are still
protected by copyright. (Making a scanned copy for backup would be
legit, but not selling that scanned copy separate from the original.)
http://en.wikipedia.org/wiki/Copyright is a nice background piece.
sieler at allegro.comwww.allegro.com/sieler/wanted/index.html
--- Tony Duell <ard at p850ug1.demon.co.uk> wrote:
> > Going slightly OT, I assume the same thing
> > would happen to any rubber rollers in VHS
> > players, and be the main (only?) reason why
> > VHS players start chewing VHS tapes?
> I've not (yet) aeen a video recorder where the
> rollers have turned to
> goo. Not saying it can't happen, though.
> The usueal reason for tape chewins is wear on the
> reel-drive idler which
> means the tape is not wound nack into the cassette
> on eject (And may not
> be properly taken up during play/record, so it get
> tangled round bits of
> the machine). Or wear of the backtension band so
> that the tape loops on
> the feed side of the head during play/record and
> gets tangled. Or wear on
> the pinch roller so that the tape runs away from t
> correct path.
> Assuming the heads are still good, a set of roller
> and tension band is
> not expensive. Setting up the back tension is 'fun
> and you will need a
> service manual for the machine (but hey, do you
> really have a machine
> that you don't have the service manual for?).
Service manual?!!! The only service manual I
know I have is for my car. Everything else
I have has manuals, but the service bit usually
requires ringing the manufacturer to get them
I know I have the VCR manual here somewhere.....
Andrew D. Burton
aliensrcooluk at yahoo.co.uk
Over the weekend, I got out two old DC-600 tape drives out of storage
- a Wangtek and an Archive. Only the Wangtek has a SCSI-to-QIC24
interface board, but I think I can use that on either drive (the board
may in fact be originally from the Archive drive anyways).
Anyways, after a quick visual inspection and wiping some dust off, I
did try it with an old DC-600 tape cartridge - one that I knew was not
important. It loaded OK and I started an attempt to image the tape to
About 1/4 into the tape something started vibrating, quickly
escalating and before I could do anything, the tape stopped. Result:
rubber goo on the plastic roller that drives the DC-600 cartridge
drive belt, some on the tape itself, and the tape shows deformation
(wavy) on the top half. I had to toss it.
The drive itself: the rubber roller driving the aforementioned plastic
roller had melted. Clearly visible is the area where the rubber meets
the cartridges' roller - the rubber is notched. Furthermore the
rubber roller is no longer cylindrical. Luckily there seems to be no
other damage to the drive - no rubber seems to have been deposited on
the R/W head.
Any idea what could have caused this and how to prevent it? I now
have two options: I can move the SCSI-to-QIC24 interface to the
Archive drive, but I want to make sure that the same doesn't happen
there. The other option is to remove the melted rubber roller and
steal the one from the Archive drive.
The mechanisms of the drives are different (the Archive has a lever
mechanism, whereas the Wangtek has a spring-loaded push mechanism) so
it's hard for me to tell if I can even move the rubber roller. Is
this maybe a component that can easily be obtained elsewhere?
Good morning Heinz,
My name is Pete and I work for a company that is trying to find a good home for (2) COM units that utilize the PDP8E computers. Did you ever market yours? Do you have any suggestions for marketing mine? Do you have any ideas about how to determine their value? Do you know anyone that is still utilizing this computer? We also have (2) RKO5 disk drives that also need a good home. Any and all suggestions will be welcomed.
R. Peter Merecki
Tony Duell wrote:
and you will need a service manual for the machine (but hey, do you really
have a machine that you don't have the service manual for?).
Yes, many machines. I can buy a new VCR/DVD combination for $89 with a one
year warrenty. Why would I want to waste a weekend repairing a worn out
VCR? That is time much better spent playing with my own designs, writing a
utility routine, or working on some old unique piece of computer gear.
Repairing a cheap piece of consumer electronics may be fun but the critical
shortage in my life is time. There is never enough to do all the fun
things, so I have to pick what gives the most pleasure. Repairing something
just to say I can do is not on my list of priorities.