Can someone point me to somewhere where I can get a case cracker of some
sort? I don't think I'm going to score an official Apple one, so I'll
settle for one that looks like the one on this page:
http://www.answers.com/topic/case-cracker
--
David Griffith
dgriffi at cs.csubak.edu
A: Because it fouls the order in which people normally read text.
Q: Why is top-posting such a bad thing?
A: Top-posting.
Q: What is the most annoying thing in e-mail?
>
>Subject: Re: Unknown S100 system
> From: "Roy J. Tellason" <rtellason at verizon.net>
> Date: Fri, 21 Sep 2007 16:35:41 -0400
> To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org>
>
>On Friday 21 September 2007 16:01, Chuck Guzis wrote:
>> On 21 Sep 2007 at 14:07, Roy J. Tellason wrote:
>> > I wonder why they went with that part? I seem to remember some others
>> > that used it as well, though specifics are not coming to mind at the
>> > moment. I have a bunch of those on hand, and think about doing
>> > something with them from time to time. It's a fairly easy chip to use,
>> > with an eprom and a ram chip and a single address latch, I just haven't
>> > decided yet what I'm gonna do with it.
>>
>> Compupro 85/88 board; my own Durango F-85 and a host of others. If
>> you can find some of the support chips (8155, 8755), the parts count
>> can be very low, given the vintage of the 8085.
>
>Compupro was the one that was hanging out there at the edge of recall...
There was a really nice 8085 system on a board that ran CP/M from Autocontrol
the AC-85. Its featurees were a 5mhz 8085, DMA, 64k ram, FDC, 3 serial channels
and a real time clock interrupt. What made it unique is the DMA was there
to support the FDC for full DSDD 8" and it also unburdened the cpu for
background tasks and interrupt servicing.
>I may have some of those support chips, too. 8155 (and 8156, which is the
>same part with a different select pin polarity if I'm remembering right)
>sound real familiar. I have the 8085 Cookbook and a few others that Sams put
>out, one covering this text editor and assembler (which I didn't really care
>for, but...). No interest in the ROM-based 8355 and I've never seen the
>EPROM-based 8755. The relative i/o and RAM address mapping of those parts
>gets a little confusing, though, and the book is a bit less clear than it
>could be on that aspect of it.
I have tubes of the 8085 support chips (8155, 8156, 8755) they can also be
used with 8048, 8051, 8088 or pairs for the 8086. The Eprom 8755 is easy
to find and still available from various sources.
A system using an 8085, 8155, 8755 has the following:
2k Eprom
256bytes ram
1 Timer (8155)
38 io lines (8755 and 8155)
3 maskable interrupts
1 trap (non maskable interrupt)
SID and SOD lines (serial IO)
It is/was popular in embedded systems and robotics.
They were also available in CMOS and Rad-hard CMOS making them useful
for extraterrestrial systems.
>> I suspect that the reason 8088/8085 pairs were fairly common in
>> comparison to Z80/8088 pairs was that timings and buses on the 8088
>> and 8085 are *very* similar and getting them to work with 8000-series
>> peripherals was very easy. IIRC, one could even replace an 8085 with
>> an 8088 (assuming you were restricting it to 64K addressing) with a
>> minimum of "glue". Both multiplex the data lines on A0-A7 the same
>> way.
Exactly. Also the 8085 was available to at least 6mhz. The 64k/1m
addressing differnce was taken care of with a simple address mapping
scheme for the 8085. Compupro used it as most using the 8088 and later
boards wer more interested in the 16bit cpu rather than any of the
8 bitters so z80/8085 was not an issue as it was a migration tool
and allowed the use of older CP/M software. Most CP/M commercial
software ran the 8080 programming model.
>> I suspect it might be easier to substitute an NSC800 for an 8085 if
>> Z80 functionality is needed than trying to shoehorn in a Z80.
>
>That's another part I have no familiarity with at all at this point in time,
>though of course I've heard of it.
Not easilly done as the NSC800 is both scarce and it's timing is
different enough to complicate matters.
>
>With regard to what little programming I've done, the thing I like most about
>the z80 is relative jumps, which makes relocatable code easy to do. The
>other big deal is the alternate register set and the index registers, which
>I really haven't used all that much.
>
The items that make z80 desireable for programming to me are the repeat
instructions (LDIR) and the loop (DJNZ) plus some of the smaller instructions
that make the CPU more symetrical. It always bugged me that 8080 can load the
SP but storing it required clearing the HL and adding SP to HL.
What makes the 8085 appealing is in small systems it has hardware advantages
like internal clock oscillator, multiple maskable interrupts, two pins for
single bit IO (SID/SOD), easier timing compared to z80. It doesnt hurt that
it's an upward 8080. it also doesnt hurt that faster parts (6mhz) had far
less difficult memory timing than 6mhz z80. It's also common as house
flies still.
NSC800, had a short product life, I don't think National ever got it
faster than 4mhz, production volumes were small and I rarely ever see
one.
8088/86, hardware around it was easy, hated programming it. Always felt
it was an 8080 with a bag on the side and borrowed the worst z80 features.
It's big cache was it's was 16bit and had the ability to address 1mb.
Allison
How many of you are located near government liquidation preview areas?
I'm wondering if we can't pool our efforts a little in evaluating lots
on govliquidation.com by helping each other preview stuff that is
local to us but not to someone else.
I'm local to Hill Air Force Base in Ogden, UT.
Anyone else?
--
"The Direct3D Graphics Pipeline" -- DirectX 9 draft available for download
<http://www.xmission.com/~legalize/book/download/index.html>
Legalize Adulthood! <http://blogs.xmission.com/legalize/>
On 9/23/07, Zane H. Healy <healyzh at aracnet.com> wrote:
> At 10:46 PM -0700 9/22/07, David Griffith wrote:
> >Can someone point me to somewhere where I can get a case cracker of some
> >sort? I don't think I'm going to score an official Apple one, so I'll
> >settle for one that looks like the one on this page:
> >
> >http://www.answers.com/topic/case-cracker
>
> I've used a clamp like you would use for holding up a tarp while
> welding. Yes, this is a really bad explanation. You shove the tip
> in the crack, and as you squeeze the clamp open, it pries the case
> apart.
That is, essentially, what at least the third-party crackers were - a
flat-metal A-frame spring-clamp with a tip about 3/4" wide, and thin
enough that the tips on both sides would fit in the groove around the
Mac case. They are commonly made of chromed sheet metal with red
plastic-dip handles.
Hopefully that description will help you spot one in a hardware/home
improvement store. They shouldn't be expensive.
-ethan
Using the 8085 instead of a Z-80 was absolutely the right decision (and if
you are wondering, who made that decision ..... it was me).
The objective was to do a dual processor system with an 8088 and some 8-bit
CPU that would run CP/M. It would have been extremely difficult to have
done that with a Z-80, it was trivial with an 8085 (using a Z-80 would
probably have taken an additional almost 2 dozen ICs ... the external
hardware and bus interfaces and signals were just totally different).
Further, the performance of the 8085 was (ok, arguably) higher .... true, we
were stuck with the 8080 instruction set, but the 8085 ran at 5MHz (later
6MHz) with FAR better timing margins than a 4MHz Z-80. There were things
that, in retrospect, we might have done differently (strapping the 8088 for
"min" mode instead of "max" mode, for example), but using the 8085 wasn't
one of them. All commercial software used 8080 instructions, and the
machine was primarily for running MS-DOS anyway. From our perspective (as
the manufacturer) we never felt a downside to that decision.
Barry Watzman
Former computer product line director
Heathkit and Zenith Data Systems
On Friday 21 September 2007 13:56, Chuck Guzis wrote:
> Unlike the Rainbow, the use of the 8085 was probably not such a great
> idea after Heath/Zenith had been producing Z-80 systems.
I wonder why they went with that part? I seem to remember some others that
used it as well, though specifics are not coming to mind at the moment. I
have a bunch of those on hand, and think about doing something with them
>from time to time. It's a fairly easy chip to use, with an eprom and a ram
chip and a single address latch, I just haven't decided yet what I'm gonna
do with it.
> Can anyone help me identify my latest PDP-11 rescue. Not been able to
> get a good look at it yet as it is in a room packed (and I mean packed)
> with junk. Machine consists of a DEC Datasystems cab (about 35-40U with
> a blue bottom panel, pretty similar to light blue cabs here:
> http://www.computermuseum.li/Liste/Digital/PDP11.70.4.html)
> I'm not familiar with the DEC Datasystems versions of PDP-11s. Does
> anyone have any background information on them?
> Also, I'm pretty sure I've not lucked out and found an 11/70 as no
> toggle switch console, any ideas on what other models were fitted to
> these cabs. I'm guessing 11/34.
That is an 11/70, but with the "remote diagnostics console". You will
find a M8255 KY11-RE in there to connect up a modem to give remote console
access. Probably hooked up to a modem that was owned by DEC maintenance
org and leased as part of the maintenance agreement. I'm sure that
sometimes they asked for the modem and console back if the maintenance
contract was terminated but as a practical matter I find that they hardly
ever reclaimed the equipment.
Tim.
Your description fits PERFECTLY a Heathkit / Zenith Data Systems Z-100
series computer (actually, Z-110 or Z-120 series). I am sure, from you
description, that this is what it was. It's actually a very common system
as S-100 systems go .... about 100,000 were built, five to ten times more
than Imsai or SOL-20 systems.
>
>All of the S100 systems I've seen to date have comprised a backplane
>and then cards for various system components - including CPU and
>memory. However, I unearthed one today which held much of the system
>logic on the backplane itself (i.e. more like a modern-day PC
>motherboard - I'd heard such things existed, but this is the first one I've
actually seen).
>Unfortunately I forgot to bring the thing home with me, so I'm a bit
>light on remembered details (but can get more tomorrow if needs be).
>However, it appeared to have both an 8088 and 8085 CPU on board,
>memory, what is probably ROM, a handful of S100-bus [1] connectors,
>parallel port, a light-pen port (unusual!), plus a few other ports (at
>least one was serial I expect). There were a few other IDC-style pin
>headers too - perhaps for some sort of storage, but none of them were
obviously labeled as to function.
>
>Sound familiar to anyone?
Kind of posting on a whim that this might be something obvious...
All of the S100 systems I've seen to date have comprised a backplane and then
cards for various system components - including CPU and memory. However, I
unearthed one today which held much of the system logic on the backplane
itself (i.e. more like a modern-day PC motherboard - I'd heard such things
existed, but this is the first one I've actually seen).
Unfortunately I forgot to bring the thing home with me, so I'm a bit light on
remembered details (but can get more tomorrow if needs be). However, it
appeared to have both an 8088 and 8085 CPU on board, memory, what is probably
ROM, a handful of S100-bus [1] connectors, parallel port, a light-pen port
(unusual!), plus a few other ports (at least one was serial I expect). There
were a few other IDC-style pin headers too - perhaps for some sort of storage,
but none of them were obviously labeled as to function.
Sound familiar to anyone?
[1] Of course the only thing to make me think it's S100 is that the connectors
are the right type; there's a possibility that it's some totally random bus
specific to whatever system this is :-)
cheers
Jules
Can an ordinary modular handset cord be used for a keyboard cable on a
Kaypro? I forget if one can be used as-is or if one plug needs to be
attached upside down.
--
David Griffith
dgriffi at cs.csubak.edu
A: Because it fouls the order in which people normally read text.
Q: Why is top-posting such a bad thing?
A: Top-posting.
Q: What is the most annoying thing in e-mail?
the problem is that a regular modular handset cord is a smaller gauge wire than what came with the Kaypro. You may be able to get away with it, but the current draw of the keyboard is a bit much for the regular cord and may not be reliable.
-----Original Message-----
>From: David Griffith <dgriffi at cs.csubak.edu>
>Sent: Sep 22, 2007 10:37 AM
>To: cctalk at classiccmp.org
>Subject: Kaypro keyboard cable pinout
>
>
>Can an ordinary modular handset cord be used for a keyboard cable on a
>Kaypro? I forget if one can be used as-is or if one plug needs to be
>attached upside down.
