Re: S-100 VDP prototype board PCBs are here

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

Hi
That's the plan however the timing of the VDP probably does not
support most of the older VGA monitors.  Possibly we can connect a VGA
HD15 connector to it any way and drive some of the newer LCD
monitors.  We are doing something like that with the new ColorVDU
board on the N8VEM list.  It converts CGA to a VGA display and some of
the newer monitors are able to sync.

The primary display at first is the composite video and once that is
working let's see if we can get VGA to work as well.  The S-100 VDP
prototype is mostly but not quite there yet.

Thanks and have a nice day!

Andrew Lynch

On Feb 10, 4:36 am, Elsid <le...@swiftdsl.com.au> wrote:
> I had a look at the uPD7720 V2 ECB circuit and I can see where the
> BT478 color output pins are taken to the VGA connector. Were the color
> outputs of the BT478 meant to be used the same way on the S-100 VDP
> board?
>
> Leon
>
> On Feb 10, 8:15 am, Elsid <le...@swiftdsl.com.au> wrote:
>
>
>
> > Thanks for the info about the FMS6141.
> > I'll give it a try using the 2N3904 first.
>
> > I was trying to undersand how the BT478 is being used in the circuit.
> > Is it being used as a digitizer or external DAC?
> > I can't see the RED, GRE and BLU pins being taken out to any header in
> > the circuit.
>
> > Leon
>
> > On Feb 9, 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/1...
>
> > > 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 -
>
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