I was surprised to find a local supplier clearing old stock of 2112 RAMs.
This is an NMOS static RAM 256bit x 4. The chips are new, labelled SY2112-A
(Synertek I think) and they're supposedly 350 nS devices.
I believe this was the chip used in late-model Commodore PETs (after they
designed out the earlier 6550 chips); maybe someone wants to confirm this
for the list. I seem to recall the Heathkit micro trainer used a couple
too, but I could be mis-remembering.
Not as commonly needed as the 2102 or 2114 I know, but if anybody wants some
I could pick them up. They're 5 for a buck, plus whatever it costs to mail
them-- unless of course you want to offer me something extra for my trouble
:)
--
Arlen Michaels
arlen.michaels(a)sympatico.ca
I just came across a large number of loose 2102 chips in a junkbox, and
wondered if anyone has a schematic of a test circuit for these. I'm not
sure how many of them there are yet, but they all appear to be from the
same batch; AM9102BPC/P2102A-4 7632QD [32nd week, 1976]. An couple
interesting facts I dug up on these chips is that the AM9102 was AMD's
first RAM product, and it was first produced in quantity in 1975.
I'm thinking these chips might be a good source of ram for a 6800 based
homebrew system, especially since I already have the chips and lots of
wirewrap (and patience)...
-Toth
After a trip down to Asian Pearl, Al and I took a
trip down to the local recycle place. He spotted an
Apple 3.5 inch External drive, the 800k variety we
were discussing recently on the list. He wasn't
interested, so I snagged it, and it appears to be
working fine on the Mac IIci, although I wasn't
sure at first, as it took me a while to find any
800k disks.
Outside, I found an IBM Type 9331 011 8 inch external
floppy drive, a nice black enclosure with the IBM logo
in the oval badge set at 45 degrees, like the PS/2 line
logos were. The interface connector on the rear has 37
pins and so I'm hoping it's the same as the interface
on the old IBM floppy interfaces that had a 37-pin
external connector.
Anyone know what these drives were used with, and will
I luck out on the interface? It needs cleaning...
Also, an IDE removable harddrive carry case & two mounting
frames, so I can start carrying serious storage two & fro
the orifice, er, office.
No blinkenlights, although the poprietor indicated he'd
dumped a bunch of old stuff six months ago. Oh well, the
way he does this is he leaves a pallet out front for people
to stack stuff on. I'll start checking more often.
Anyway, total damage for the above: eight bucks; five for
the Apple drive, two for the IBM floppy, and 1 for the IDE
shuttles.
-dq
> I got a type 9331 model 011 with an AS/400 system... I
> think. When I get home, I'll look at it (and its //manual// :)
> again.
Excellent, and thanks in advance!
-dq
> From: "Stan Sieler" <sieler(a)allegro.com>
> To: cdl(a)proxima.ucsd.edu (Carl Lowenstein), classiccmp(a)classiccmp.org,
> classiccmp(a)classiccmp.org
> Date: Fri, 3 May 2002 12:10:42 -0700
> Subject: Re: Tape dumping programs for Unix/Linux...
> Priority: normal
> In-Reply-To: <200205030710.AA16219(a)proxima.ucsd.edu.UCSD.EDU>
>
> Re:
>
> > Look for a program named "copytape". It copies tapes including the
> > block structure, file marks, etc. Unlike dd(1) which only really
> > works if all blocks are the same size and there is only one file
> > on the tape. It can copy tape-drive to tape-drive or tape-drive to
> > disk file, and puts markers in the disk file to indicate the
> > structure of the data on the tape.
> >
>
> The versions I found do a fair job of copying a tape...but not
> a complete job (particularly for DDS and DLT tapes).
>
> Why?
>
> It doesn't know about "setmark".
>
> On a DDS (DAT) drive, you can have a data record (of variable length,
> not just multiples of 128 or 256 bytes, BTW), an EOF (end-of-file mark),
> a setmark, or an end-of-tape indicator.
OK. It _was_ written long before anything as smart as a DAT drive
had been devised.
Why do you stress "data record not just multiples of 128 or 256 bytes"?
Oh, this is qualified by "on a DDS drive". Certainly 7-track and 9-track
1/2" drives could have fairly arbitrary data records. I have seen
tapes with records as short as 14 bytes, and as long as 65535 bytes.
Also pre-DLT tapes (DEC TK50) with 1MB records, but only to be read
by a MicroVax not a PDP11.
> >From "man mt" on HP-UX (since at least 1992, so it fits the 10 year rule, too
> :)
> DDS format devices also support setmarks which are hierarchically
> superior to filemarks. A setmark is used to delineate a group (set)
> of files. Reading a setmark is also returned as a zero-length read.
> The two can be distinguished by unique bits in the mt_gstat field.
>
> (In fact, #$%^ HP took out the above text from the 10.20 "man mt" doc, leaving
> just a bare reminder that setmarks exist)
>
> Who uses setmarks? Backup software that wants to be able to locate
> files quickly.
>
> E.g., consider a modified tar/gtar that writes an EOF after every
> file, and a setmark after every 1000 files, and also writes s table
> of contents (list of files to be backed up) at the start of the tape.
> If the user says "restore file FOO", the software can read the table of
> contents and determine that FOO is file, say, 2349. It can then issue
> two "forward setmark" commands, and then 349 "forward EOF" (or "forward
> filemark" or "forward space file") commands to quickly get to the file.
>
> DDS drives can find a setmark very quickly, faster than they can find
> an EOF.
>
> So....any software trying to *accurately* duplicate a tape should
> record the fact a setmark was seen, as well as data record and EOFs
> and errors :)
As I recall, DDS tapes can also have two partitions, independently
writeable. So the tape index can be written onto the first partition
_after_ the data is written on the second partition. I don't know any
common software that takes advantage of this.
carl
--
carl lowenstein marine physical lab u.c. san diego
clowenstein(a)ucsd.edu
Hi
One could throw together a simple socket and connector
circuit to put on a parallel printer port. Use a '273 to
increase the number of outputs and use one pin as the input.
The pins for the 2102 are 1,2,4,5,6,7,13,14,15 and 16 are
address lines. 3 is MWR\. 11 is data in and 12 is data out.
10 is +5 and 9 is ground.
You do need a bi-directional parallel port.
Check out : http://www.lvr.com/jansfaq.htm for ideas
on how to control the printer port of a PC ( I would
do it with Forth, myself but most others would use C
or something ). Write a March "C" and pause between passes
for a few seconds to check retention.
Dwight
>From: Tothwolf <tothwolf(a)concentric.net>
>
>I just came across a large number of loose 2102 chips in a junkbox, and
>wondered if anyone has a schematic of a test circuit for these. I'm not
>sure how many of them there are yet, but they all appear to be from the
>same batch; AM9102BPC/P2102A-4 7632QD [32nd week, 1976]. An couple
>interesting facts I dug up on these chips is that the AM9102 was AMD's
>first RAM product, and it was first produced in quantity in 1975.
>
>I'm thinking these chips might be a good source of ram for a 6800 based
>homebrew system, especially since I already have the chips and lots of
>wirewrap (and patience)...
>
>-Toth
>
>
A power supply for an RS/6000 397.
Peace... Sridhar
--
"How do you fight such a savage?"
"With heart, faith, and steel. There can be only one."
-MacLeod and Ramirez, "Highlander"
Anyone need a power supply for an RS/6000 380/390/390H/3AT/3BT/3CT?
Peace... Sridhar
--
"How do you fight such a savage?"
"With heart, faith, and steel. There can be only one."
-MacLeod and Ramirez, "Highlander"
I picked up another Mac SE today, and it's got a "Macintosh SE PC Drive
Card" installed in it, with a big connector on the back of the SE. What is
the card for?
--
Owen Robertson
JP Hindin <jplist(a)globe.net.nz> wrote:
> I see le0 a lot, but I picked up ie0 from my Sun 4/470, which I'm using on
> the 386i. Is this an error on my part? Should I try and set up le0
> instead?
Maybe. ie is the driver for an Intel Ethernet chip/card (I have
vague recollections of the card being a Multibus card in a VME-to-
Multibus frame in a Sun 4/370). le is the driver for an AMD LANCE
chip. I can't remember what Ethernet hardware is in the 386i,
but a LANCE-based design would not be surprising.
Does your 386i boot at all? If so I would expect it to tell you at
boot time what devices the kernel is finding. If you can log in, the
dmesg command should replay those messages for you (if they're still
in the kernel's buffer).
-Frank McConnell
