Re: 6502 board resistor networks

[yoda <yo...@r2d2.org>]

I was just suggesting typical values of pull-ups  - I would generally
use 1K for faster rise times but have seen 4.7K used when that is not
an issue.  What I was trying to point out is that specifying 1.3 K
resistor networks is just going to raise questions by inexperienced
builders as I have found no place to source such networks and new
builders are not going to find them.  I think we should have some
general guidelines that we use common readily available components (I
understand there are special cases where that is not possible).

On Jan 12, 1:04 am, John Monahan <mon...@vitasoft.org> wrote:
> In generally 1k is sufficient for TTL Pullups. The reason for higher values is to save power drain on the v regulator. You can go up to about 4.7k
> Pullups to bus lines are another story
> Joh
>
> Sent from my iPhone
>
> On Jan 11, 2012, at 7:12 PM, yoda <y....@r2d2.org> wrote:
>
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> > Hi Andrew
>
> > Would it be possible to have some design rules in general.  I have
> > seen a lot of these boards use parts that are not easily obtainable
> > which suggests these are copies of old boards without thought.  If
> > they are supposed to be pull-up resistors then in general I would
> > expect 1K or 4.7K be specified as they are pretty standard.  I checked
> > Jameco, Digikey and Mouser and they don't have 1.3 K.  I know
> > experienced people can interpret schematics but it tends to discourage
> > new people into the hobby that don't have that experience.  Also it
> > would be nice to do some standardization of buss interface.  I see
> > this board uses ls541's where most other boards use ls373's so one has
> > to "stock" many more parts to participate.
>
> > Just a thought
>
> > Dave
>
> > On Jan 11, 6:50 pm, "Andrew Lynch" <LYN...@YAHOO.COM> wrote:
> >> Hi Kipp!  The 1.3K ohm resistors are all pull up resistors and have a broad
> >> tolerance.
>
> >> Almost certainly the 1.2K ohm resistors will work just fine.
>
> >> Thanks and have a nice day!
>
> >> Andrew Lynch
>
> >>> -----Original Message-----
> >>> From: n8vem...@googlegroups.com [mailto:n8vem-
> >>> s1...@googlegroups.com] On Behalf Of kyeakel
> >>> Sent: Wednesday, January 11, 2012 10:44 AM
> >>> To: N8VEM-S100
> >>> Subject: [N8VEM-S100:655] 6502 board resistor networks
>
> >>> I couldn't find 1.3k ohm resistor networks. I have 1.2k networks, any
> >> issue
> >>> with using them?
> >>> Kipp