On Mon, 05 Jun 2006 06:08:17 GMT, dgriffi@cs.csbuak.edu (Dave
Griffith) wrote:

>It doesn't run CP/M, but I'm sure it'll interest some of you. Over on
>the cctalk (http://www.classiccmp.org/lists.html) list, the guy who made
>the SBC6120 single board PDP8 clone is taking names for a new run of
>boards. The more people who express interest, the better the chances of
>him going forward with a new run. Hopefully he can be talked into doing
>a new run of front panel kits too.
>
>Read about this SBC at
>http://www.sparetimegizmos.com/Hardware/SBC6120-2.htm

Correction. The board has been in continous production for several
years and the call was a "last call" as parts were getting scarce.
Same is true for the pannel.

Bottom line is when sales are only a few a year or diminishing there
is a question should one buy ans stock the parts to continue or is it
time to declare it end of life?

I am not associated with this board or the production of it. Only
that I've been aware of STG for some 10 years or more with various
projects and products Bob has sold had going back to a solid state
replacement for a TU58 DECtape.

Allison

In article ,
nospam@nouce.bellatlantic.net wrote:

> On Mon, 05 Jun 2006 06:08:17 GMT, dgriffi@cs.csbuak.edu (Dave
> Griffith) wrote:
>
> >It doesn't run CP/M, but I'm sure it'll interest some of you. Over on
> >the cctalk (http://www.classiccmp.org/lists.html) list, the guy who made
> >the SBC6120 single board PDP8 clone is taking names for a new run of
> >boards. The more people who express interest, the better the chances of
> >him going forward with a new run. Hopefully he can be talked into doing
> >a new run of front panel kits too.
> >
> >Read about this SBC at
> >http://www.sparetimegizmos.com/Hardware/SBC6120-2.htm
>
> Correction. The board has been in continous production for several
> years and the call was a "last call" as parts were getting scarce.
> Same is true for the pannel.
>
> Bottom line is when sales are only a few a year or diminishing there
> is a question should one buy ans stock the parts to continue or is it
> time to declare it end of life?
>
> I am not associated with this board or the production of it. Only
> that I've been aware of STG for some 10 years or more with various
> projects and products Bob has sold had going back to a solid state
> replacement for a TU58 DECtape.
>
> Allison

Sort of suprised that CPU is still available. Does it have any uses
other then something like this?

At least a z80 is still used in a lot of embedded products. ( not a slam
on the 6120, just curious about its current day 'market' )

In article ,
dgriffi@cs.csbuak.edu (Dave Griffith) wrote:

> It doesn't run CP/M, but I'm sure it'll interest some of you. Over on
> the cctalk (http://www.classiccmp.org/lists.html) list, the guy who made
> the SBC6120 single board PDP8 clone is taking names for a new run of
> boards. The more people who express interest, the better the chances of
> him going forward with a new run. Hopefully he can be talked into doing
> a new run of front panel kits too.
>
> Read about this SBC at
> http://www.sparetimegizmos.com/Hardware/SBC6120-2.htm

Im hoping the *minimal* z80 board i want to do turns out to be simple
enough that anyone can do it.. It may or may not run cpm out of the box
since im going for really minimal hardware, but it wouldnt be hard with
a 'extension module'.

Had to switch attention to other things for a few weeks ( I have a sick
car and i hate driving the 'spare' around in this weather ) but I've not
lost interest the project, yet.

I still need to find a SIO or 2, does anyone sell them anymore?

> I still need to find a SIO or 2, does anyone sell them anymore?

I believe that BG Micro and JDR both have
4MHz versions in unit quantities.

Digikey has them in bulk, @ ~6$ X 130
- ridiculous, but 6,8, and 10 Mhz avail.

Mouser has unit quantities, ~7.50$,
6,8, 10(?)MHZ avail.

HTH,
Tarkin

ziggy wrote:

> Im hoping the *minimal* z80 board i want to do turns out to be simple
> enough that anyone can do it.. It may or may not run cpm out of the box
> since im going for really minimal hardware, but it wouldnt be hard with
> a 'extension module'.

So, what's the objective for your Z80 board? What advantages does it
have over the P112? This isn't intended to lord the P112 over yours.
There are several things about the P112 that I'd like to redo if/when I
have the time. Maybe this summer I'll see if I can do something for
your Z80 project.

I'd like to see something comparable to the P112 in versatility and
power but adding the following:

1) Two layer circuit board which permits easy board etching at home.

2) All through-hole and easy to find parts.

3) A stack-up style expansion connector that's easier to source. The
socket called for on the mainboard is easy enough to find, but I have to
special-order ones with longer tails from the manufacturer. Soldering
is also a pain.

4) Provisions for a front panel. Ideally this would combine what you
get from an IMSAI 8080 and the Jade Bus Probe.


--
David Griffith
dgriffi@cs.csbuak.edu <-- Switch the 'b' and 'u'

In article ,
dgriffi@cs.csbuak.edu (Dave Griffith) wrote:

> ziggy wrote:
>
> > Im hoping the *minimal* z80 board i want to do turns out to be simple
> > enough that anyone can do it.. It may or may not run cpm out of the box
> > since im going for really minimal hardware, but it wouldnt be hard with
> > a 'extension module'.
>
> So, what's the objective for your Z80 board? What advantages does it
> have over the P112? This isn't intended to lord the P112 over yours.
> There are several things about the P112 that I'd like to redo if/when I
> have the time. Maybe this summer I'll see if I can do something for
> your Z80 project.
>
> I'd like to see something comparable to the P112 in versatility and
> power but adding the following:
>
> 1) Two layer circuit board which permits easy board etching at home.
>
> 2) All through-hole and easy to find parts.
>
> 3) A stack-up style expansion connector that's easier to source. The
> socket called for on the mainboard is easy enough to find, but I have to
> special-order ones with longer tails from the manufacturer. Soldering
> is also a pain.
>
> 4) Provisions for a front panel. Ideally this would combine what you
> get from an IMSAI 8080 and the Jade Bus Probe.

Im not trying to outdo the P112 at all. the P112 a modern, advanced and
perhaps the 'best' choice for a modern-day plug and play CPM machine.

The "advantages" to what im proposing is that it will be a really simple
and traditional base, with options for expansion for 'extras', like
disk, video, extra I/O ports, A/D etc.. ( even a front panel interface
like you want ). Trying to keep the base board to CPU/RAM/ROM and 1
serial, 1 parallel.. The bare minimum.

It has to be an easy to etch 2 sided board and easy assemble at home, no
SMT chips or esoteric components.. A true hobbiest 'roll your own'
thing. Was thinking similar to the PC104 type of stackable boards, or
can use ribbon cable between them..

CPM will even end up being a option that will have to be dealt with
afterwards.. ( and will require some of the optional add-on boards )

> I still need to find a SIO or 2, does anyone sell them anymore?

Hey, ziggy, have I got a deal for you.
I have:
2 x 44-pin PLCC Zilog SCC's, pn Z85C3008SVC
1 x " " " DMA, pn Z84C1008VEC

As they are PLCC, I have little or no use for them.
You get dibs; if you're not interested, somebody else may
want them.

I will accept in trade the following:

1 POKEY chip suitable for use in a stock Atari 800
1 8255/82C55A or equivalent
1 FDC, WD1791 or better/equivalent.

Or best offers. I will be out of town and unable
to ship for a week, but will check my email and
respond to those interested.

TTFN,
Tarkin

Dave Griffith wrote:
[snip]

>
> I'd like to see something comparable to the P112 in versatility and
> power but adding the following:
>
> 1) Two layer circuit board which permits easy board etching at home.
>
> 2) All through-hole and easy to find parts.
>
> 3) A stack-up style expansion connector that's easier to source. The
> socket called for on the mainboard is easy enough to find, but I have to
> special-order ones with longer tails from the manufacturer. Soldering
> is also a pain.
>
> 4) Provisions for a front panel. Ideally this would combine what you
> get from an IMSAI 8080 and the Jade Bus Probe.
>
FWIW, some of the design decisions I made when I created the P112, 11
years ago:
1. Given I wanted a 3" drive form factor, I really couldn't use
thru-hole CPU and memory chips (not enough room). Remember, the 40-DIP
Z80 is just a CPU: you need all the peripherals separately.
2. I wanted current-production (1995) chips: that ruled out most of the
40-DIP diskette controllers, even had there been room.
3. Having burned my fingers with ground noise once before, I took no
chances, & opted for a 4-layer board. Never had any noise problems with
those. That's not to say it can't be done 2-layer, of course; just I
wanted to be sure it would go first time.
4. Back in 1995, that stack-up connector was readily available here in
Australia. Times change, of course.

David R Brooks wrote:
> FWIW, some of the design decisions I made when I created the P112, 11
> years ago:
> 1. Given I wanted a 3" drive form factor, I really couldn't use
> thru-hole CPU and memory chips (not enough room). Remember, the 40-DIP
> Z80 is just a CPU: you need all the peripherals separately.

This wishlist of mine would probably mean abandoning the 3" drive form
factor.

> 2. I wanted current-production (1995) chips: that ruled out most of the
> 40-DIP diskette controllers, even had there been room.

I hear that there are some reimplementations of the old 40-DIP
controllers done in GAL, PEEL or something else like that.

> 3. Having burned my fingers with ground noise once before, I took no
> chances, & opted for a 4-layer board. Never had any noise problems with
> those. That's not to say it can't be done 2-layer, of course; just I
> wanted to be sure it would go first time.

That's another gremlin that would force me to abandon the 3" format.

> 4. Back in 1995, that stack-up connector was readily available here in
> Australia. Times change, of course.

Maybe a staggered stack-up would be more future-proof.

--
David Griffith
dgriffi@cs.csbuak.edu <-- Switch the 'b' and 'u'

On 2006-06-10, Dave Griffith wrote:
> David R Brooks wrote:
>> FWIW, some of the design decisions I made when I created the P112, 11
>> years ago:
>> 1. Given I wanted a 3" drive form factor, I really couldn't use
>> thru-hole CPU and memory chips (not enough room). Remember, the 40-DIP
>> Z80 is just a CPU: you need all the peripherals separately.
>
> This wishlist of mine would probably mean abandoning the 3" drive form
> factor.

Could go with an ATX motherboard form factor...

--
roger ivie
rivie@ridgenet.net

In article <1149907640.317434.156300@j55g2000cwa.googlegroups. com>,
"Tarkin" wrote:

> > I still need to find a SIO or 2, does anyone sell them anymore?
>
> Hey, ziggy, have I got a deal for you.
> I have:
> 2 x 44-pin PLCC Zilog SCC's, pn Z85C3008SVC
> 1 x " " " DMA, pn Z84C1008VEC
>
> As they are PLCC, I have little or no use for them.
> You get dibs; if you're not interested, somebody else may
> want them.
>
> I will accept in trade the following:
>
> 1 POKEY chip suitable for use in a stock Atari 800
> 1 8255/82C55A or equivalent
> 1 FDC, WD1791 or better/equivalent.
>
> Or best offers. I will be out of town and unable
> to ship for a week, but will check my email and
> respond to those interested.
>
> TTFN,
> Tarkin

Trying to stick with DIP chips in what im doing, but thanks for the
thought

In article ,
Roger Ivie wrote:

> On 2006-06-10, Dave Griffith wrote:
> > David R Brooks wrote:
> >> FWIW, some of the design decisions I made when I created the P112, 11
> >> years ago:
> >> 1. Given I wanted a 3" drive form factor, I really couldn't use
> >> thru-hole CPU and memory chips (not enough room). Remember, the 40-DIP
> >> Z80 is just a CPU: you need all the peripherals separately.
> >
> > This wishlist of mine would probably mean abandoning the 3" drive form
> > factor.
>
> Could go with an ATX motherboard form factor...

Or 5.25" form.. Lots of small cases available for that size. Think
external CDROM cases..

In article <1149647573.441242.114350@y43g2000cwc.googlegroups. com>,
"Tarkin" wrote:

> > I still need to find a SIO or 2, does anyone sell them anymore?
>
> I believe that BG Micro and JDR both have
> 4MHz versions in unit quantities.
>
> Digikey has them in bulk, @ ~6$ X 130
> - ridiculous, but 6,8, and 10 Mhz avail.
>
> Mouser has unit quantities, ~7.50$,
> 6,8, 10(?)MHZ avail.
>
> HTH,
> Tarkin

I didnt find them while searching on digikey's site. ill go look again.
I have to hit up the shops here in town to, we have 3 of them. They are
often more $ then mail order, but they are close.

Didnt think to look at jameco. I tend to forget about them, and in the
old days that all i ever bought from. ( well that and polypack )

ziggy wrote:

> I didnt find them while searching on digikey's site. ill go look again.
> I have to hit up the shops here in town to, we have 3 of them. They are
> often more $ then mail order, but they are close.

> Didnt think to look at jameco. I tend to forget about them, and in the
> old days that all i ever bought from. ( well that and polypack )

I've long given up on getting anything useful from local shops. A while
ago I went into one looking for a 74ls279. The guy behind the counter
turned around to get one from a bin, then made a big show of blowing
dust off of it. He wanted $10 for it. I also needed some 28-pin dip
sockets. $30 for a package of four.

Sometime later I went in looking for resisters in quantities larger than
Radio Shack could provide. I felt like I was in the Cheese Shop sketch.


--
David Griffith
dgriffi@cs.csbuak.edu <-- Switch the 'b' and 'u'

Roger Ivie wrote:
> On 2006-06-10, Dave Griffith wrote:
>> David R Brooks wrote:
>>> FWIW, some of the design decisions I made when I created the P112, 11
>>> years ago:
>>> 1. Given I wanted a 3" drive form factor, I really couldn't use
>>> thru-hole CPU and memory chips (not enough room). Remember, the 40-DIP
>>> Z80 is just a CPU: you need all the peripherals separately.
>>
>> This wishlist of mine would probably mean abandoning the 3" drive form
>> factor.

> Could go with an ATX motherboard form factor...

How is everyone mounting their P112s anyhow? I just cobbled a simple
bracket to mount mine in a SCSI case.

--
David Griffith
dgriffi@cs.csbuak.edu <-- Switch the 'b' and 'u'

>I've long given up on getting anything useful from local shops. A while
>ago I went into one looking for a 74ls279. The guy behind the counter
>turned around to get one from a bin, then made a big show of blowing
>dust off of it. He wanted $10 for it. I also needed some 28-pin dip
>sockets. $30 for a package of four.

Sadly the only electronics shop near me
(Green Brook electronics NJ) is the same way:
they have the small parts & tools in single unit quantities,
but they're asking $10+ for parts that ought to be $1-2 tops.
How I miss Canal Street of the 70s
with all the surplus electronics stores.
--

-- mejeep deMeep ferret!

>> Could go with an ATX motherboard form factor...

Why not AT format and re-use the cases
that nobody else can re-use?
There were many thin 286/386 desktop cases perfect for projects.

>Or 5.25" form.. Lots of small cases available for that size. Think
>external CDROM cases..

The nice external cases have the fan and power supply internal,
such as the Sun 411 or 600 cases.
--

-- mejeep deMeep ferret!

On Sat, 10 Jun 2006 14:33:10 -0400, ziggy
wrote:

>In article ,
> Roger Ivie wrote:
>
>> On 2006-06-10, Dave Griffith wrote:
>> > David R Brooks wrote:
>> >> FWIW, some of the design decisions I made when I created the P112, 11
>> >> years ago:
>> >> 1. Given I wanted a 3" drive form factor, I really couldn't use
>> >> thru-hole CPU and memory chips (not enough room). Remember, the 40-DIP
>> >> Z80 is just a CPU: you need all the peripherals separately.
>> >
>> > This wishlist of mine would probably mean abandoning the 3" drive form
>> > factor.
>>
>> Could go with an ATX motherboard form factor...
>
>Or 5.25" form.. Lots of small cases available for that size. Think
>external CDROM cases..

That's more the size I had in mind.