>From: Joe <rigdonj(a)cfl.rr.com>
>
>At 08:26 PM 12/14/02 -0800, you wrote:
>>I was trying to get some information on this old B1702A chip. I know
>>it is a 256x8 chip but someone told me that "B" marked chips are
>>normally gray with tin leads.
>
> I was wondering about the "B" markings. I was sorting a bunch of
surplus chips a few days ago including a big pile of 2716s and I found one
marked "B 2716". (The complete markings are "i B2716 023D3-V (c) INTEL
'77") It has a large square window of frosted material and the window is
rasied above the IC surface. All the D 2716s have smaller round clear
windows that are flush with the IC surface. The B part and most of the D
parts all have tinned leads and gray bodies.
>
>>
>>This one is white ceramic with gold leads. I tried finding something
>>on this but have not found this particular marking and colors.
>>Anyone know the skinny?
>>
>>http://www.msdsite.com/temp/1702a2.jpg
>
>
>>http://www.msdsite.com/temp/1702a.jpg
>
> I looked at this picture and saw the "1602" die marking. The Intel 1602
was a PROM and not an EPROM and other than being non-eraseable was
completely compatible with the 1702. I suppose they used the same die but in
different packaging. I'm guessing that your 1702 is an early one. I just
sold a 1602 to a collector, I think it was the only one that I had ever
seen.
>
Hi
I have either a 1702 or may it is a 1701, non-A, someplace.
There were not many of these made.
Most all of the early 1702's were put into the gold lead
with the clear quartz windows, glued on. It wasn't until
later that they started to use the frosted glass and then
later still when they used the monolithic ceramic/quarts
that had the clear( but distorted ) window.
Dwight
Got the following:
1. Another joystick for the Micro Genius IQ150 Perfect console. ($3)
2. Radio Shack TRS-80 Pocket Computer Cat no. 26-3501, not tested yet. ($2)
3. OT: iMac no KB or mouse with it but it's a 400 MHZ/521k LC/128MBRam/13gig
HD/DVD/2 Firewire/ pretty clear blue see-thru color. ($15) model M5521
4. Sega Genesis 32X game unit. ($5)
5. About 8 different mice and 12 mousepads for the collection. (Free to 99
cents)
J.C.Wren wrote:
> ...< a lot of soldering wisdom, then>...
> Probably nobody has really read this far, and I can't think of anything
>else at the moment, and my fingers are tired.
Twice. Then saved it for good measure. Thanks! I'll start saving for a Metcal.
- Mark
On Sun, 15 Dec 2002 ard(a)p850ug1.demon.co.uk (Tony Duell) wrote:
> > On Thu, 12 Dec 2002 ard(a)p850ug1.demon.co.uk (Tony Duell) wrote:
> >
> >
> > > > Huh? No. Actually, the data track itself is used as the servo signal. The
> > > > head centers in on the track by centering on where the amplitude is
> > > > strongest.
> > >
> > > Do you have any evidence for that?
> >
> > Yup. I quote:
> > "1.3.3.2 Sector Format - As shown in Figure 1-3, each sector contains:
>
> OK, let me quote the RL01/RL02 Disk Drive Technical Manual.
[...]
Seems like you had the better manual at hand. I'll check it out tomorrow,
when I'll pass by where I have that manual.
> > * Servo information for head positioning
>
> Sure, I'll agree the servo bursts are in the sector header. They are just
> not radially aligned with the data track. I guess you're working from a
> manual that oversimplifies things.
RL01/RL02 Disk Subsystem User's Guide.
> > Eh. This is on most controller not something you check or take care about
> > in software, but hardware. When you specify to the controller (for
> > instance en RK11) that you want track 10, it both figures out how many
> > tracks the heads need to move, and in which direction. It then checks that
> > you really are at the right track, otherwise you get an error back.
>
> I am _darn_ sure the seek function on an RK11 doesn't check sector
> headers (I would have to actually dig out the prints to be sure). I know
> I've used it to move heads around on the alignment pack, which doesn't
> have convnetionally recorded headers. Quite apart from the fact that an
> RK05/RK11 can seek on a blank disk so as to be able to format it (a blank
> RK05 pack really is blank).
We must have been talking past each other here. I didn't mean that the
controller/drive made a check on the disk that it was on the right
track. The drive *knows* it's on the right track, without checking. Like
you said, the RK05 can seek on a blank disk, and format it.
> > The RL11 have no such sophistication. You request a head move, and the
> > drive hopefully does it, and then you can carry on with the next
>
> That's what most controllers do. The difference is that on the RK11, you
> specify the cylinder you want to move to, and the drive (hopefully) goes
> there. You then have to check headers. On the RL11, you have to work out
> how many cylinders to move and in which direction (That bit of the
> calculation is done automatically by the RK system).
No, on an RK11 (well, admittedly I've mostly played with the RK8E) you
really don't ever check the header yourself. In fact, you can actually
start the disk transfer even if you're not on the right track. The drive
will do an implicit seek as a part of the transfer for you. Also, track
switching can occur in the middle of the transfer, without you seeing or
caring about it. Not on the RL. You cannot even switch heads in the middle
of a transfer.
> > information is constantly checked by the controller, it should be
>
> Eh, if you're making your own controller, you don't need to check the
> headers...
True. But noone said we were going to build our own controller until
now. :-)
> > Basically, if you don't have the servo information correct on the platter,
> > the drive will signal errors to the controller, and the controller which
> > just miserably fail unless header infomration keep coming in when the
> > drive is running.
>
> Ifyou don't have the correct servo information, the drive won't keep the
> heads loaded (well, it certainly won't keep them on-track). At this
> point, no controller could do anything useful with the drive.
Unless you have a drive without servo information, such as the RK05.
Johnny
Johnny Billquist || "I'm on a bus
|| on a psychedelic trip
email: bqt(a)update.uu.se || Reading murder books
pdp is alive! || tryin' to stay hip" - B. Idol
Thanks for putting up with my earlier ad. All the VAXen equipment I posted about has been claimed.
-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
Bruce Lane, Owner & Head Hardware Heavy,
Blue Feather Technologies -- http://www.bluefeathertech.com
ARS KC7GR (Formerly WD6EOS) since 12-77 -- kyrrin(a)bluefeathertech.com
"I'll get a life when someone demonstrates that it would be superior
to what I have now..." (Taki Kogoma, aka Gym Z. Quirk)
>It's always 'Deck' round here, at least amongst hackers. DEC employees
>pronounced it 'Digital' and tended to get annoyed when I refered to the
>company as 'Deck'.
You obviously met the wrong employees :-)
>Unfortunately I don't know (remember) which version was used
>to create the disk image... it was done about 8-10 years ago.
If you have access to OpenVMS, you can run BACKUP/ANA
to produce a whole bunch of extra information about
what is in there.
Antonio
LOCAL PICKUP ONLY -- SHIPPING NOT AVAILABLE DUE TO SIZE/WEIGHT
----
Fellow Classiccomp'ers and VAXen-lovers,
I need to make room. I've got three MicroVAXen in great shape that I want to get out of here. One is a MicroVAX 3 in the BA123 (end table) cabinet with 32MB RAM. I've SCSI-fied it with a Sigma RQD11S card. Said card will handle both disk and tape drives. In fact, this particular machine already has NetBSD (don't remember which version) loaded.
Second machine: VAX 4000-200 in the skinny tower cabinet. This one also works well, though I don't remember how much memory it has. It had a CMD CQD220 SCSI card in it which has been transferred (by me) to Machine #3, which is...
A VAX 4000-400 in the 'wide' tower cabinet. Also works well, and I think it's got either 48 or 64 megs RAM.
ALSO INCLUDED: MicroVAX hardware service manuals, whatever spare DEC'ish boards I have left, etc.
Here's the deal; I'm located in Kent, WA (southeast of Seattle by about 35 minutes). I don't have the facilities to palletize this stuff or get it shipped, so we're doing LOCAL PICKUP ONLY.
Because of the SCSI cards, and the fact that there's lots of extras. I'm going to ask a price of $150.00 or best offer for the whole works. YOU PICK UP -- SHIPPING NOT AVAILABLE.
You can contact me via E-mail at the human-readable address in my signature block. If your reply bounces, use my backup address of kc7gr (a/t) qsl dot net.
Thanks much.
-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
Bruce Lane, Owner & Head Hardware Heavy,
Blue Feather Technologies -- http://www.bluefeathertech.com
ARS KC7GR (Formerly WD6EOS) since 12-77 -- kyrrin(a)bluefeathertech.com
"I'll get a life when someone demonstrates that it would be superior
to what I have now..." (Taki Kogoma, aka Gym Z. Quirk)
I have N* software on floppies plus a bunch of hard-sectored 5.25"
floppies... Interested?
Will J
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On Dec 14, 21:40, Merle K. Peirce wrote:
>
> I have arrived. I was just spammed by Ron Popeil.
:-) But did you buy <whatever it was>?
--
Pete Peter Turnbull
Network Manager
University of York
