Re: [N8VEM-S100:702] Re: S-100 VDP prototype board PCBs are here

[Neil Breeden <nbre...@comcast.net>]

Yes, the LM385BZ-1.2 is a different package, from it's data sheet it looks like only 2 of its 3 pins are used so it should be usable, I have one on order and will post pics once I know it works.

Sent from my iPad

On Feb 9, 2012, at 4:48, lynchaj <lyn...@yahoo.com> wrote:

> 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 -