S-100 board PCB planning

Rod Smallwood rodsmallwood at btconnect.com
Tue Nov 9 03:42:25 CST 2010

    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.

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
> bouncing back.
> Hi Andrew.
>     I am restoring a Northstar Horizion. Would any of your boards be
> 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,  
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 
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.


> 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
> we did a major update/respin cycle to the boards and made manufactured
> 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
> 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
> 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
> 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
> schematics, PCB layouts, bill of materials, etc are available on either
> N8VEM wiki or S100Computers.com website including build instructions for
> 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
> 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
> 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

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