Re: S-100 VDP prototype board PCBs are here

[lynchaj <lyn...@yahoo.com>]

Hi,
The FMS6141 is optional but provides improved video amplification if
installed.  The transistor amplifier will also work and probably just
as well.  All the N8 builders AFAIK used the transistor and it worked
fine.

I am not sure the status of the 1.2V Zener diode but the BT478
datasheet was pretty specific about the part number.  They did say the
part could be substituted with equivalent components (page 4-33) but
finding any 1.2V Zener diode may be a trick.

We used a similar circuit on the uPD7220 video board so maybe this
will be helpful

http://n8vem-sbc.pbworks.com/w/browse/#view=ViewFolder&param=ECB%20uPD7220%20GDC

NS LM385BZ-1.2 is a part number but the package seems to be a
mismatch.

Thanks!

Andrew Lynch

PS, we could ask John Coffman if he recalls what we did on the uPD7220
board.

On Feb 8, 9:17 pm, "Neil Breeden" <nbre...@comcast.net> wrote:
> Yes - The N8. Does anyone recall the video config's with/without the
> FMS6141?
> -N
>
>
>
> -----Original Message-----
> From: n8vem...@googlegroups.com [mailto:n8vem...@googlegroups.com] On
>
> Behalf Of Max Scans
> Sent: Wednesday, February 08, 2012 4:41 PM
> To: n8vem...@googlegroups.com
> Subject: Re: [N8VEM-S100:700] Re: S-100 VDP prototype board PCBs are here
>
> Hi Neil,  I think the N8 was the other board you were referring to
>
> Cheers,
>
> Max
>
> Sent from my iPhone
>
> On 09/02/2012, at 10:42 AM, "Neil Breeden" <nbre...@comcast.net> wrote:
>
> > The FMS6141 is a video filter, as I recall you can leave it off and go
> > with the 2N3904 based amp instead, it needs to be one or the other, not
> both.
>
> > I ordered the 6141 from Digikey -
> >http://search.digikey.com/us/en/products/FMS6141CSX/FMS6141CSXCT-ND/13
> > 05865
>
> > Note that I have NOT verified the info below, it is based on looking
> > at the schematic.
>
> > If you use the FMS6141 I believe these other parts are needed as well:
>
> > P36 FMS4161
> > R28 0 Ohm (wire jumper)
> > R29 470 Ohm
> > C24 0.1uF
> > R30 75 Ohm
> > R31 75 Ohm
> > C26 220uF
> > C27 0.1uF
> > Jumper L1 (this will supply VCC to the FMS6141) or use an Inductor
> > bead to limit noise back onto VCC
>
> > If you are not using the FMS4161 then you will also need:
>
> > Q1 2N3904
> > C25 22uF
> > L1 Inductor Bead
>
> > Again this is a guess based on what I see in the schematic; there was
> > a discussion some time ago on another thread about a similar design on
> > another board; I haven't been able to find that discussion however.
>
> > -Neil
>
> > -----Original Message-----
> > From: n8vem...@googlegroups.com [mailto:n8vem...@googlegroups.com]
> > On Behalf Of Elsid
> > Sent: Wednesday, February 08, 2012 12:53 PM
> > To: N8VEM-S100
> > Subject: [N8VEM-S100:698] Re: S-100 VDP prototype board PCBs are here
>
> > When I checked my parts for the VDP I discovered I'd forgotten the
> > FMS6141 IC.
> > There doesn't seem to be anything available locally that will do the job.
> > It'll take about a week to come in from RS Components. I know they are
> > a bit pricey, but they don't have a minimum order for their free
> > delivery if you order online in Australia, unlike Element 14 or
> > XON(Mouser agents) or Digikey. (I don't have any association with RS)
>
> > Leon
>
> > On Feb 8, 8:08 am, Elsid <le...@swiftdsl.com.au> wrote:
> >> Hi Neil,
>
> >> I think I have most if not all of the parts for the VDP now.
> >> I will most likely build the board this weekend.
> >> What were you going to try as far as software?
> >> I thought I'd try building a text driver for CP/M 3 first, though it
> >> would be nice to see MSX running on an S-100 machine.
>
> >> Leon
>
> >> On Feb 8, 4:37 am, "Neil Breeden" <nbre...@comcast.net> wrote:
>
> >>> I'm wondering who else is testing / building an S-100 VDP board?
>
> >>> I have my board assembled and all the parts in hand with the
> >>> exception of one part, the 1.2V zener/voltage reference. Nobody in
> >>> my area stocks the voltage reference listed in the schematic, I'm
> >>> waiting to get an order above the minimum on Digikey so I can kick
> >>> off
> > an order.
>
> >>> -Neil
>
> >>> From: n8vem...@googlegroups.com
> >>> [mailto:n8vem...@googlegroups.com] On Behalf Of Andrew Lynch
> >>> Sent: Thursday, December 29, 2011 4:35 PM
> >>> To: n8vem...@googlegroups.com
> >>> Subject: [N8VEM-S100:634] S-100 VDP prototype board PCBs are here
>
> >>> Hi!
>
> >>> I've already sent S-100 VDP prototype board PCBs to Dave and Neil
> >>> for build and test.
>
> >>> However if anyone else would like to participate in the build and
> >>> test phase please let me know.
>
> >>> This is going to be a fun project and has the potential for somewhat
> >>> VGA compatibility.
>
> >>> It also lays the foundation for a potential MSX2 compatibility for
> >>> the S-100 bus.
>
> >>> That's unprecedented AFAIK.  It could be very interesting!
>
> >>> It is not recommended for new builders though -- this will be "blood
> >>> and guts" all the way!
>
> >>> Thanks and have a nice day!
>
> >>> Andrew Lynch- Hide quoted text -
>
> >> - Show quoted text-- Hide quoted text -
>
> - Show quoted text -