9 Nov
2010
9 Nov
'10
8:01 a.m.
On 11/09/2010 04:42 AM, Rod Smallwood wrote:
Hi
Thanks for the reply. Well I do have a genuine (N*H) motherboard.
The serial I/O is on the motherboard so I am assuming it will boot to ROM
Monitor with just the N*H CPU card in position. As you confirm that it?s a
generic S100 motherboard then other non N*H S100 boards may well run.
Wrong on the boot monitor. Standard NS* the boot is on the FDC card
and is only enough to boot a floppy. the nominal location for that boot
rom is E800 and is either 256(SD) or 512(DD) bytes.
A minimal NS* must have CPU, FDC with one drive, and 16K ram,
and the left serial prot configured/populated to boot/run NSdos.
As NS* basic is nearly 24K a usable system is 32K but 56K is preferred.
The backplane is a standard S100 bus save for the back end has two
serial IO,
parallel IO, and interrupt and heartbeat logic. Most other vendors put that
on a seperate serial parallel card. That area also contains the 5V/12V
regulators
for the dual floppies. There is NO rom back there.
If you want a bootable monitor I suggest a CPU-Z or similar with rom on
the cpu
card and put your own or some prefered monitor in that. the best address
for that
rom and (any extra ram) is in the 0xF000 to 0xFFFF block. This space is
normally
unused in NS* systems as the FDC fills the 0xE800-0xEFFF block breaking
up the
address space.
Cards I know run well in the NS* backplane..
Compupro: CPU-Z, DIsk1(and A), Disk2, Disk3, MPX1, Interfacer
series,M-driveH,
and ram16, 17 (all ram if CPU-Z is used due to banking). I've also used
the 8085/8088 card with ram22 and 23 boards.
NOTE: the CPU-Z can be configured with 2k Eprom and 2K ram (at f000 and
f800)
making it desirable to debug a dead NS* system.
SBC880 cpu [my prefered card to test and debug a dead NS*.]
California Computer Systems cards all work, note they also have banking so
jumper must be set to match the CPU in use. [ I have a spare full set of CCS
cards in a third NS* chassis that work fine.]
Generally the NS* Z80 cpu card is a good one but the rom position is
2708 and
hard to populate making it harder to use for debugging a dead system.
The typical failure point for dead NS* systems or boards is either the
bus interface
chips because people pull the card before waiting for the bus voltages
to bleed down
or the FDC has a problem (won't boot). The most common FDC problem is
not bus level
interface chips is crappy sockets. During part of the production life
NS* used a cheap
side wipe socket and they fatigue and make bad/intermittent/no contact.
I've worked on
a large number of FDC boards (both SD and DD) with this problem.
The other problem to note is that a SD system will not boot a DD disk
and a DD system
will not boot a SD disk(it can read/write it but not boot it). Find a
source of 10 hole
hard sector media as it is scarce.
Allison
Regards
Rod Smallwood
-----Original Message-----
From: cctech-bounces at classiccmp.org [mailto:cctech-bounces at classiccmp.org]
On Behalf Of allison
Sent: 08 November 2010 22:08
To: General Discussion: On-Topic Posts Only
Subject: Re: S-100 board PCB planning
On 11/08/2010 01:20 AM, Rod Smallwood wrote:
********************** Attention Bob Rosenbloom
***********************
Please contact me at rodsmallwood at btconnect.com my email re NS boards
keeps
bouncing back.
Hi Andrew.
I am restoring a Northstar Horizion. Would any of your boards be
suitable
substitutes for the original NS ones?
As NS* user the answer is sorta. The board will plug in but none are NS*
replacements if only the include things NS* never imagined or implemented.
In short, all of those boards can be used in a NS* Horizon as the backplane
in that machine is generic S100 and oddly enough 99% IEEE696 compatable
(needs terminations, and only for 8bit IO) and already has two serial,
parallel
ports, interrupt logic plus interrupt control. However stock NS* cards
are not
completely 696 compatible so some care with mixing them needs to be taken.
The yabut is that none are replacement cards, though most would extend the
machine nicely especially the z80/floppy and the IDE.
I happen to have two NS* horizons.
One I built in 1978 and all the boards are non stock and it has things like
10mhz z80(modified Compupro CPU-Z), 256kB ram with banking, 8085/765
smart FDC (supports 8" and 3.5", BIOS on board), Teltek HDC (2 D540s for
62mb total),
smart IDE/CF(64MB installed, smart part if the BIOS is fully implemented
it it),
512K MdriveH ramdisk, 256K romdisk, CompuPro MPX1 (intelligent IO slave),
Smart printer buffer(128K/8049), fast serial (8049 8251) for buffered
serial support.
Generally runs a very modified version of CP/M-80 with multitasking and
mountable
drive support added.
The other is a rock stock NS* 64K Horizon with either a SD or DD controller
( I have both for it). Runs NSDOS, CP/M, UCSD Pascal.
Allison
Regards
Rod Smallwood
-----Original Message-----
From: cctech-bounces at classiccmp.org [mailto:cctech-bounces at classiccmp.org]
On Behalf Of Andrew Lynch
Sent: 06 November 2010 15:34
To: cctalk at classiccmp.org
Subject: S-100 board PCB planning
Hi! Over the last couple of years several of us at N8VEM,
S100computers.com, and others have been building S-100 boards. This
summer
we did a major update/respin cycle to the boards
and made manufactured
PCBs
for many builders. For a while it seemed to
satisfy the demand for DIY
hobbyist S-100 PCBs but now the interest is starting to pick up again so I
thought I would send an update to any S-100 enthusiasts on CCTALK.
I will reorder/respin S-100 PCBs once the interest level gets to an
economically viable level for a group purchase. Normally that is around
25-30 PCBs I know builders want which makes a cost at $20 plus shipping
per
PCB affordable for most builders. This
compromise balance seems to work
well and we've produced several S-100 boards this way. Here are the
boards
we've made so far:
S-100 regular prototyping board (some remaining)
S-100 buffered prototyping board (some remaining)
S-100 backplane (8 slot plus utility circuitry - one left)
S-100 IDE (hard drive, CD-ROM, CF, ATAPI, etc)
S-100 parallel ASCII keyboard (just received a new batch of respin
PCBs)
S-100 4MB SRAM (Flash, etc)
S-100 system monitor (similar to Jade Bus Probe but two PCB set -
one or two remain)
S-100 bus extender (with logic probe, indicator LEDs, etc)
S-100 EPROM (SRAM, EEPROM, Flash, etc)
S-100 IO (dual serial, USB, voice synthesis, etc)
S-100 PIC/RTC
All of these have gone through at least one or two internal prototype
iterations plus one or more manufactured PCB orders. Since we respin the
boards based on builder feedback obviously the later generations of boards
tend to be "cleaner" than the earlier ones. This is an all volunteer
amateur project so the builders *are* the developers, QA, testers, etc in
addition to using the boards.
There are four boards in active development and/or approaching
manufactured
PCB stage
S-100 Z80 CPU (just ordered first batch of manufactured PCBs after
two rounds of prototype build and test)
S-100 Console IO (dual Propeller VGA, PS/2 keyboard, microSD,
Ethernet, etc - first iteration prototype boards ordered)
S-100 ZFDC intelligent floppy drive controller (Z80/WD2793 second
iteration prototype board imminent)
S-100 68K CPU (first iteration prototype boards ordered)
Please note the above boards no longer *planned* they are actual boards in
some form or another. There are several more in the planning stages but I
won't waste your time with those since those plans change often. All of
the
schematics, PCB layouts, bill of materials, etc
are available on either
the
N8VEM wiki or S100Computers.com website including
build instructions for
the
most part.
These are noncommercial Do It Yourself (DIY) hobbyist PCBs. They are not
perfect nor is this a business. John's apt description from comp.os.cpm
captures it well "Andrew Lynch (at N8VEM) see
(http://n8vem-sbc.pbworks.com/) and I, are in the process of having a few
commercial quality S-100 cards made for ourselves. If others are
interested
in obtaining a bare card, let Andrew or I know.
Please note these would be
bare cards, a schematic and that's it. Building the board and implementing
CPM etc., you are on your own. This is not a project for first timers."
In other words, if you want to play along that's great but this is purely
"CAVEAT EMPTOR" and there are no assurances, guarantees, or warrantees on
any aspect of the boards.
Please this is offered as an information post to interested
vintage/classic
computer hobbyists not an invitation for flames
and pointless criticisms.
Please be courteous and keep those to yourself. As always, questions,
comments and *constructive* criticism welcome.
Thanks and have a nice day!
Andrew Lynch