>From: "Pete Turnbull" <pete(a)dunnington.u-net.com>
>
>On Jun 4, 14:14, Joe R. wrote:
>> Dwight,
>>
>> I have a programmer that's suppsoed to be for the intel 2704 and
>2708.
>> I've never seen any info on the 2704 and I've never seen one but I'm
>> guessing that it's a half bad 2708. Do you know any more about it?
>
>Maybe. If so it must have been identified before the leads were added,
>because the Intel Data Catalogue 1976 lists both 2704 and 2708 on the
>same page, and the only difference is pin 22. On a 2708, that's A9, on
>a 2704 it's always 0V (always 0V, cf 2716/2758 below). No pictures,
>unfortunately, so no immediate way to tell if the dies look the same.
>
>Interestingly, the 1976 book doesn't list anything bigger than a 2708.
> So a 2708 obviously wasn't a half-bad 2716 (at least, Intel ones
>weren't).
Hi
No, I was talking about Intel's 2508( maybe 2758 from your later
note ), not the 2708 that was a multi-voltage part.
Dwight
>
>The 1979 Data Catalogue lists the 2704 only as a footnote to the 2708
>description, and the 2716 appears only as a single-rail version. I
>thought they did both, but I must have been thinking of another
>manufacturer.
>
>The 1979 book lists 2716, 2732, and 2578. The 2758 has exactly the
>same power consumption, access times, programming, and pinout as the
>2716, except that pin 19 is A10 on a 2716 and is AR on a 2758. AR is
>"select reference input voltage". The tables show this as always Vil
>(ie, 0V) but in one place only, the small print says that it's always
>0V *except* for devices labelled "2758 S1865", when it needs to be Vih
>(+5V). Hmm, that sounds exactly like Dwight's description of a half
>bad chip to me :-)
>
>
>--
>Pete Peter Turnbull
> Network Manager
> University of York
>
Oops, I deleted the original so can't reply directly to it :-(
I hope someone has better info than me, because although I think I have
a 16KZ-K for my Cromemco, the only manuals I can find are for Godbout,
Irvine, Integrand, Tuscan, and a few other memory boards -- none of
which I have!
All I can find is the entry in the 1978 Cromemco Microcomputer Systems
catalogue, which says that it offers expandability to 512K bytes with
bank select, has fully-transparent dynamic refresh, operates at 4MHz
with no wait states, and costs $495 (fully assembled, tested, and
burned in, as the 16KZ-W, is $595).
"With bank select each memory board may reside in one or more
of the 8 possible memory banks. An 8-position DIP switch on
the board is used to select each of the banks in which the
board resides.
"The active bank or banks of memory are selected under software
control. Output port 40H is dedicated to this function. Each
of the 8 bits of data of output port 40H are used to turn on or
off the corresponding bank of memory. A "1" in the
corresponding bit position will turn on the memory bank. A "0"
will turn it off. All circuitry required to detect the output
of 40H is included on the memory card itself.
"Bank select provides a convenient method by which to expand
system memory space beyond 64K. Bank select also permits the
implementation of time-sharing systems with a minimum of
software overhead - up to 8 users can use the system
simultaneously with each confined to his own bank of memory."
This implies the card can be multiply decoded (to appear more than
once). I imagine if you want it to appear from 0000H to 0FFFFH, you
turn on the switch in position 1, and turn off the rest (unless you
want it to appear elsewhere as well). Similarly to appear from 10000H
to 1FFFFH, switch position 2. Although, since it's easier to provide a
pullup resistor than a pulldown on TTL, likely "switch on" grounds the
line and means a "0". Try it and see!
--
Pete Peter Turnbull
Network Manager
University of York
On Jun 4, 14:14, Joe R. wrote:
> Dwight,
>
> I have a programmer that's suppsoed to be for the intel 2704 and
2708.
> I've never seen any info on the 2704 and I've never seen one but I'm
> guessing that it's a half bad 2708. Do you know any more about it?
Maybe. If so it must have been identified before the leads were added,
because the Intel Data Catalogue 1976 lists both 2704 and 2708 on the
same page, and the only difference is pin 22. On a 2708, that's A9, on
a 2704 it's always 0V (always 0V, cf 2716/2758 below). No pictures,
unfortunately, so no immediate way to tell if the dies look the same.
Interestingly, the 1976 book doesn't list anything bigger than a 2708.
So a 2708 obviously wasn't a half-bad 2716 (at least, Intel ones
weren't).
The 1979 Data Catalogue lists the 2704 only as a footnote to the 2708
description, and the 2716 appears only as a single-rail version. I
thought they did both, but I must have been thinking of another
manufacturer.
The 1979 book lists 2716, 2732, and 2578. The 2758 has exactly the
same power consumption, access times, programming, and pinout as the
2716, except that pin 19 is A10 on a 2716 and is AR on a 2758. AR is
"select reference input voltage". The tables show this as always Vil
(ie, 0V) but in one place only, the small print says that it's always
0V *except* for devices labelled "2758 S1865", when it needs to be Vih
(+5V). Hmm, that sounds exactly like Dwight's description of a half
bad chip to me :-)
--
Pete Peter Turnbull
Network Manager
University of York
>From: "Tom Jennings" <tomj(a)wps.com>
>
>On Thu, 2004-06-03 at 18:18, Fred Cisin wrote:
>
>> > We used to pay $80 for a box of DSDD Dysan 8" floppies and align the
>> > disk drives every year with a Dysan alignment diskette and an
>> > oscilloscope. That's what it took for repeatable reliability. It sucked.
>>
>> ... and yet nobody was buying 8" Dysan alignment diskettes and new
>> shrinkwrapped Dysan floppies at $1 per diskette at VCF! My biggest
>> market segment was teachers who each wanted ONE diskette to wave in
>> the air when talking to classes about the days of dinosaurs.
>
>No, and you don't see people wearing onions around their neck anymore to
>ward off illness either.
>
>Man, like many others I used to do edits and huge (sic) compiles and
>library building and linking, HOONK HOONK HOONK for hours, every day,
>for however long an individual floppy lasted. (1.25MB each, seemed like
>a lotta space at the time.) THAT ate up floppies and drives! I put
>solidstate relays on the big AC motors and let them run down after some
>idle period, that helped.
Hi
A handy thing to have is a handfull of bearings and a bearing
puller.
Dwight
>From: "Roger Merchberger" <zmerch(a)30below.com>
>
>Rumor has it that Nico de Jong may have mentioned these words:
>
>> > I have a DEC RX01 drive and the box of floppies that I have
>> > with it are 8 inch single sided single density. Are 8" hard
>> > sectored floppies compatible with these?
>>
>>Hard and Soft sectored disks are never compatible.
>
>Ah, never say never, my friend! ;-)
>
>I know little about 8" floppies, but I know that Apple ][ 5.25" drives
>(which used GCR encoding, IIRC) could use hard or soft sector floppies. It
>actually wrote an "index blip" (for lack of the correct term) on the disk
>itself during format & used that instead of any physical hole(s) in the disk.
>
Hi
I also believe that one can use hard sectored disk in place of
soft sectored disk in most machines( of course formatted as soft
sectored ).
There is a difference between single and double
density that is related to the position of the index hole. My
understanding is that unlike the 5-1/4 disks, the 8 in. media
is the same for the single and double density, just higher
quality. In fact, I punch a new index window in some of my
double density 8 inch floppies and I've been using them, with
no troubles, as single density.
The 5-1/4 disk are a different story. Single/Double don't mix.
Dwight
>From: "Ron Hudson" <ron.hudson(a)sbcglobal.net>
>
>
>> On Thu, 3 Jun 2004, Tom Jennings wrote:
>> There used to be a popular folk myth that all single sided diskettes
>> actually double sided ones that had failed testing on one side.
>> I find it hard to believe that any company could be profitable
>> with THAT high a failure rate!
>>
>I once worked in memorex in the tape plant where open reel tape was made
>and that is exactly how it was done, raw tape was run through error
>detecting
>machines and sorted.
>
>
Hi
This thinking always reminds me of a story from Intel.
When they first started making 2716's, TI was biting
into their 2708 market with the 2758's. Intel fought
back with their version of the 2508. These were early
half bad failures from the 2716 line. They even had
a H/L pin to select which half to use. When they
first started, they sold for quite a bit less than
the 2716's ( about $30 ea ). Over time, the 2716's
pricing went down to around $4 someplace. I got a kick
out of seeing one of their price list showing the
2508's still being sold for $32 ea.
While I suspect that originally the half bad parts
made sense but at the premium price they got for these,
I suspect that they later just took fully tested
2716's and relabeled them.
I wonder how many purchasing agents realized that
the 2716's worked just as well.
Dwight
I have a Cromemco 64KZ-II memory board but no manual. If anyone has a
manual in PDF format, that would be ideal, but in the absence of that,
I'd settle for a short description of how the board is organized and
what the 3 dip switches and two LEDs do.
I am also looking for the following manuals if anyone has these in PDF
formats:
IMSAI VIO, MIO and SIO2-2
Processor Technology VDM-1 and 3P+S
Industrial Microsystems 8K static memory board
Seals 8K Static Ram
I have over 100 manuals in PDF format, and have made significant
contributions to the S-100 manual library at:
http://www.hartetechnologies.com/manuals/
Direct E-Mail responses would be appreciated.
Thanks,
Barry Watzman
Watzman(a)neo.rr.com
I would guess it has something to do with Labview. Labview was originally
developed on the Mac (No decent Windows GUI back then, though I think there
was an OS/2 version) Labview in a rack-mount would have been pretty sweet at
the time.
Damn, another Apple clone to add to my wish list..
>From: "Steven Canning" <cannings(a)earthlink.net>
>Reply-To: "General Discussion: On-Topic and Off-Topic
>Posts"<cctalk(a)classiccmp.org>
>To: "General Discussion: On-Topic Posts Only" <cctech(a)classiccmp.org>
>Subject: Re: Rackmount MAC Classic
>Date: Thu, 3 Jun 2004 20:08:17 -0700
>
>On Thu, 3 Jun 2004, Ram Meenakshisundaram wrote:
>
>Never seen this before:
>
>http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=4604&item=4134681929&
>rd=1
>
>A Rackmountable MAC Classic with a VME Backplane.....
>
>Wow, how cool is that?
>
>But my question is, "why?"
>
>
>To further the "why" question..... quoting my wise grandfather, "Just
>because you 'can' put a diamond in a goat's ass, doesn't mean you should
>!"
>
>regards, SAC
>
>
_________________________________________________________________
Is your PC infected? Get a FREE online computer virus scan from McAfee®
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Never seen this before:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=4604&item=4134681929&
rd=1
A Rackmountable MAC Classic with a VME Backplane.....
Ram
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On Jun 3, 21:56, Don Maslin wrote:
> On Fri, 4 Jun 2004, Pete Turnbull wrote:
>
> > The original IBM hard-sectored 8" floppies had 8 sectors, and I
don't
> > think 3M ever made those :-)
>
> Do you know how they formatted them, Pete? Perhaps 512/sector?
I don't know. I've never actually seen one (except in photos), let
alone used one. I know they only held 80K, spun in the opposite
direction to modern floppies, were much thicker, and (for the customer)
were read-only.
http://www.computerworld.com/news/1999/story/0,11280,62286,00.htmlhttp://history.acusd.edu/gen/recording/mag/p42.html
--
Pete Peter Turnbull
Network Manager
University of York
