Re: [N8VEM-S100:1386] S-100 64KIO board tool *preliminary design*

[Tom Lafleur <laf...@lafleur.us>]

This would be an ideal board for the S100 RomWBW project if the RAM
pin-out were to be change to also support 29/39F040 FLASH memory...
minor change with jumpers
one could have 32k of ram and 32k of flash .... or 64k or ram, 64k of flash...

minor points

1) if you have room, a maxim DS1210 could be added to support ram
memory back up with on board battery and with a external 3 pin
connector for aux battery....
this is what was done in zeta board...

2) I also think that the 16550 serial chip would be a better choice,
8251 are harder to get, 16550 are easy to program... requires only a
oscillator/xtal and would eliminate the hard to get AY-5-8116 and it
associates parts


my two bits...

tom...

On Sun, Feb 10, 2013 at 7:12 AM, Andrew Lynch <LYN...@yahoo.com> wrote:
> Hi
>
>
>
> Rather than confuse the S-100 bus terminator discussion with the S-100 64KIO
> board please let’s continue it here.  Attached are the *preliminary* S-100
> 64KIO board schematic and PCB layout files.  Please review so we can discuss
> at the concept level not necessarily the implementation details.
>
>
>
> The purpose of this board is to be a *tool* not a permanent system board per
> se.  It would be useful to bootstrap broken S-100 boards and system.  Sort
> of like the S-100 backplane, S-100 bus extender, S-100 SMB, etc.
>
>
>
> In theory this board would be sufficient to bootstrap an S-100 system with
> itself and bare CPU board *only* in a temporary configuration.  Once it is
> fully working either the legacy boards would be repaired and replaced or new
> boards installed.
>
>
>
> Please note that Neil is in the process of completely redesigning this board
> so don’t get lost on the implementation details.  I believe it is going to
> change very significantly if not completely.
>
>
>
> Thanks and have a nice day!
>
> Andrew Lynch
>
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Tom Lafleur
(858) 759-9692