On Sat, 26 Apr 2008 09:46:21 -0700 (PDT), lynchaj <lynchaj@yahoo.com> wrote:
: Hi,
:
: I am working on a Z80 SBC home brew project and am looking for some
: experienced persons who are interested in early testing and
: development. Preferrably with electronic technician and/or engineer
: with home brew SBC experience with your own tools and workbench.
Use a 64180 instead, the CMOS version. It's a Hitachi part. HC64C180
IIRC but it's been a long time. It's worth the $$$ in terms of real
estate you'll save on the PCB and the fun that can be directed towards
I/O and code.
On Apr 27, 7:26*pm, hgold...@mpcs.com (Howard Goldstein) wrote:
> On Sat, 26 Apr 2008 09:46:21 -0700 (PDT), lynchaj <lync...@yahoo.com> wrote:
>
> *: *Hi,
> *:
> *: *I am working on a Z80 SBC home brew project and am looking for some
> *: *experienced persons who are interested in early testing and
> *: *development. *Preferrably with electronic technician and/or engineer
> *: *with home brew SBC experience with your own tools and workbench.
>
> Use a 64180 instead, the CMOS version. *It's a Hitachi part. *HC64C180
> IIRC but it's been a long time. *It's worth the $$$ in terms of real
> estate you'll save on the PCB and the fun that can be directed towards
> I/O and code.
Hi,
The Hitachi 64180/Zilog Z180 is a pretty neat part alright. It is a
64 pin DIP component which is huge but with all the integrated
peripherals, it is a space saver overall.
While using the HD64180 is a nice thought and it would make more sense
if this project were still in the planning phase. However, since I
have already built the prototype with the Z80 CPU and written software
for it I don't really think starting over almost completely from
scratch is terribly practical. In addition, the I have ordered some
PCB prototypes and they are on their way. So a complete redesign is
pretty much out of the question as far as I am concerned.
That being said, I still consider this home brew project to be in its
initial stages. There is some simple software already (boot loader,
monitor, RTC utility, disk formatter, CP/M CBIOS, etc) but the overall
state is still pretty raw. The software will require some
modifications just due to the minor changes introduced in the PCB
transition.
In particular, I know the transition from the 32Kx8 EEPROM to the 1Mx8
EPROM introduced a new ROM memory extended addressing and
configuration latch which will have a ripple effect. I think the RTC
original design had some anomalies which I addressed in the PCB and
will require some minor software changes. Who knows what else will
shake out before it is over -- assuming the new PCB design works at
all.
One nice thing about protoboards and point to point wiring is they
give tremendous flexibility to address problems. Once the PCBs are
cut, that is it. Modifications are now all "cuts and jumpers" if
there are any changes. Permanent changes require a respin of the PCB
and that can get expensive quick.
On 2008-04-27, lynchaj <lynchaj@yahoo.com> wrote:
>
> You could be right, I have no way of knowing for sure. My guess based
> on discussions with people familiar with computers is that few do
> anything with hardware except a few brave ones may build their own
> systems or add a peripheral occasionally. Actually get out the
> soldering iron and VOM and building something is pretty rare, I think.
I'm not entirely sure where the emphasis is in this paragraph. The
routine adding of peripherals, even internal drives and expansion
cards, is commonplace and performed by even fairly nontechnical
users. In my experience even users who wouldn't know how to set
up a simple Ethernet network when the hardware is already installed
in each PC are often comfortable slotting in a new graphics card
or whatever.
As for a more component based approach, yes, it _is_ a tiny minority.
It always has been. The only exception was with the homebuilt
computer kits of the 70's such as the Altair 8800, and even then
some got others to assemble their machines, and the numbers of
people involved in the field was tiny. Even by the time of the
first 'home' computers of the early eighties - the Sinclair Spectrum,
Commodore 64 etc, very few people were designing and building
peripherals. The proportion of users doing so was greater than
today but the user base was still small by modern standards.
> Agree -- the options for integrated CPU chips like MC68HC11 and the
> Zilog Z8 family are making a PCB full of chips an obsolete form of
> electronics. Especially the PIC and AVR families of
> microcontrollers. No argument there. Making a small computer with
> the Z80 will be 5 or so large chips and about 10 to 20 small chips
> depending on what IO you add. The smallest Z80 SBC made from common
> parts (ie not programmable parts will be around 12 or so chips total)
> but will be very limited in capability.
I didn't do any actual design, just put a system together in my
head. You can do it in far less than a dozen. You need a processor,
1 chip, RAM and ROM, 1 chip each and a couple of 74 series chips
for address decoding. You can probably make up a clock with the
unused portions of the 74 series chips. Of course that doesn't
have any I/O capabilities to speak of but it serves to illustrate
the truly minimal system.
> True, what people have done with FPGA and CPLDs is amazing. Although
> I think rather defeats the whole vintage electronics feel though and
> starts to resemble computer pure programming. I can see the appeal
> though, the PCB layouts are amazingly simple and the boards are tiny
> and nearly empty. Basically just a big Xilinx FPGA in the center and
> some connectors. Maybe some passive components but few of those.
They don't have to be programmed using VHDL or Verilog - schematic
capture is also an option and is more in keeping with the traditional
way of doing things. It's what I've used myself when working with
FPGAs - I played around with them at university and never really
got to grips with them properly since. I have certainly never
learned a synthesis language. You're right that it is a different
discipline than traditional hobbyist electronics assembly, but how
is your time best spent? Dreaming up new ideas that soon reach a
level of complexity and performance you could never achieve by
hand, or by tracking down shorts and figuring out how to route so
many traces on only a double sided board?
> Maybe building 74LSxxx TTL chip homebrew computers has finally passed
> into obscurity. Oh well, at least I still enjoy it. I will continue
> the hobby simply because it is so enjoyable to make things work. Of
> course, I enjoy repairing and working with the vintage microcomputers
> of the CP/M era (Heath, NorthStar, Vector Graphic, etc) so that
> effects my view point.
I think that that is fair to say. When you cast your mind back to
when people were doing that kind of thing they weren't doing it
out of any retro interest, they were designing and building systems
that either didn't exist or otherwise couldn't afford. You seem
to have the same narrow idea in your head but time has moved on.
Sure nowadays you can buy more processing than you could ever build
yourself for a morning's pay, but people still want greater levels
of performance that the homebuilt systems of old. You can't compete
on either price or performance with commercial kit so the hobbyist
side is mainly for niche areas where commercial equipment isn't
available.
On May 1, 6:10*am, Andrew Smallshaw <andr...@sdf.lonestar.org> wrote:
> On 2008-04-27, lynchaj <lync...@yahoo.com> wrote:
>
>
>
> > You could be right, I have no way of knowing for sure. *My guess based
> > on discussions with people familiar with computers is that few do
> > anything with hardware except a few brave ones may build their own
> > systems or add a peripheral occasionally. *Actually get out the
> > soldering iron and VOM and building something is pretty rare, I think.
>
> I'm not entirely sure where the emphasis is in this paragraph. The
> routine adding of peripherals, even internal drives and expansion
> cards, is commonplace and performed by even fairly nontechnical
> users. *In my experience even users who wouldn't know how to set
> up a simple Ethernet network when the hardware is already installed
> in each PC are often comfortable slotting in a new graphics card
> or whatever.
>
> As for a more component based approach, yes, it _is_ a tiny minority.
> It always has been. *The only exception was with the homebuilt
> computer kits of the 70's such as the Altair 8800, and even then
> some got others to assemble their machines, and the numbers of
> people involved in the field was tiny. *Even by the time of the
> first 'home' computers of the early eighties - the Sinclair Spectrum,
> Commodore 64 etc, very few people were designing and building
> peripherals. *The proportion of users doing so was greater than
> today but the user base was still small by modern standards.
>
> > Agree -- the options for integrated CPU chips like MC68HC11 and the
> > Zilog Z8 family are making a PCB full of chips an obsolete form of
> > electronics. *Especially the PIC and AVR families of
> > microcontrollers. *No argument there. *Making a small computer with
> > the Z80 will be 5 or so large chips and about 10 to 20 small chips
> > depending on what IO you add. *The smallest Z80 SBC made from common
> > parts (ie not programmable parts will be around 12 or so chips total)
> > but will be very limited in capability.
>
> I didn't do any actual design, just put a system together in my
> head. *You can do it in far less than a dozen. *You need a processor,
> 1 chip, RAM and ROM, 1 chip each and a couple of 74 series chips
> for address decoding. *You can probably make up a clock with the
> unused portions of the 74 series chips. *Of course that doesn't
> have any I/O capabilities to speak of but it serves to illustrate
> the truly minimal system.
>
> > True, what people have done with FPGA and CPLDs is amazing. *Although
> > I think rather defeats the whole vintage electronics feel though and
> > starts to resemble computer pure programming. *I can see the appeal
> > though, the PCB layouts are amazingly simple and the boards are tiny
> > and nearly empty. *Basically just a big Xilinx FPGA in the center and
> > some connectors. *Maybe some passive components but few of those.
>
> They don't have to be programmed using VHDL or Verilog - schematic
> capture is also an option and is more in keeping with the traditional
> way of doing things. *It's what I've used myself when working with
> FPGAs - I played around with them at university and never really
> got to grips with them properly since. *I have certainly never
> learned a synthesis language. *You're right that it is a different
> discipline than traditional hobbyist electronics assembly, but how
> is your time best spent? *Dreaming up new ideas that soon reach a
> level of complexity and performance you could never achieve by
> hand, or by tracking down shorts and figuring out how to route so
> many traces on only a double sided board?
>
> > Maybe building 74LSxxx TTL chip homebrew computers has finally passed
> > into obscurity. *Oh well, at least I still enjoy it. *I will continue
> > the hobby simply because it is so enjoyable to make things work. *Of
> > course, I enjoy repairing and working with the vintage microcomputers
> > of the CP/M era (Heath, NorthStar, Vector Graphic, etc) so that
> > effects my view point.
>
> I think that that is fair to say. *When you cast your mind back to
> when people were doing that kind of thing they weren't doing it
> out of any retro interest, they were designing and building systems
> that either didn't exist or otherwise couldn't afford. *You seem
> to have the same narrow idea in your head but time has moved on.
> Sure nowadays you can buy more processing than you could ever build
> yourself for a morning's pay, but people still want greater levels
> of performance that the homebuilt systems of old. *You can't compete
> on either price or performance with commercial kit so the hobbyist
> side is mainly for niche areas where commercial equipment isn't
> available.
>
> --
> Andrew Smallshaw
> andr...@sdf.lonestar.org
OK, well, I guess this must be the wrong USENET group to be posting on
the subject of home brew computers.
Once I get the CP/M rehosted over to the new PCB, I'll bring up the
topic again over on comp.os.cpm.
Best of luck and have a nice day! Thanks!
Andrew Lynch
PS, if anyone is interested, I am posting updates to the Z80 home brew
project at:
================================================== ===================
1.1 What the group is about
This group was formed for the discussion of homebuilt computer
hardware, as the name implies. The term "homebuilt" or alternately,
"homebrew", refers to the hobby of building electronics at home,
generally with a soldering iron or wire wrap.
Please note: Unfortunately, the term "homebuilt" causes a great deal
of confusion amongst IBM clone builders, which leads to a large number
of inappropriate posts on this newsgroup. This group, as a general
rule, is not for discussion of IBM related hardware ...
================================================== ===================
- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.
On May 10, 11:36*pm, Franc Zabkar <fzab...@iinternode.on.net> wrote:
> On Sat, 3 May 2008 20:40:51 -0700 (PDT), lynchaj <lync...@yahoo.com>
> put finger to keyboard and composed:
>
> >OK, well, I guess this must be the wrong USENET group to be posting on
> >the subject of home brew computers.
>
> Actually you are the only one who is on-topic.
>
> http://www.faqs.org/faqs/homebuilt-comp-FAQ/
>
> ================================================== ===================
> 1.1 What the group is about
>
> This group was formed for the discussion of homebuilt computer
> hardware, as the name implies. The term "homebuilt" or alternately,
> "homebrew", refers to the hobby of building electronics at home,
> generally with a soldering iron or wire wrap.
>
> Please note: Unfortunately, the term "homebuilt" causes a great deal
> of confusion amongst IBM clone builders, which leads to a large number
> of inappropriate posts on this newsgroup. This group, as a general
> rule, is not for discussion of IBM related hardware ...
> ================================================== ===================
>
> - Franc Zabkar
> --
> Please remove one 'i' from my address when replying by email.
Franc,
As right as you may be, I am afraid there is little discussion of
homebrew computing done here anymore.
At any rate, I received the initial prototype PCBs, fully build one
machine, tested it, and it works per design. The SBC boots into a
custom monitor and will boot CP/M on demand. There were a few design
issues uncovered which I corrected in a new version of the PCB.
Nothing critical but enough to warrant a respin.
I recently updated the SBC CBIOS to support the full 1MB ROM as a
block device (F. It works great and as soon as the updated design
finishes in the autorouter / optimizer, which will probably be several
more days, I intend to order some additional PCBs for interested
hobbyists.
On May 12, 1:53*am, lynchaj <lync...@yahoo.com> wrote:
> On May 10, 11:36*pm, Franc Zabkar <fzab...@iinternode.on.net> wrote:
>
>
>
>
>
> > On Sat, 3 May 2008 20:40:51 -0700 (PDT), lynchaj <lync...@yahoo.com>
> > put finger to keyboard and composed:
>
> > >OK, well, I guess this must be the wrong USENET group to be posting on
> > >the subject of home brew computers.
>
> > Actually you are the only one who is on-topic.
>
> >http://www.faqs.org/faqs/homebuilt-comp-FAQ/
>
> > ================================================== ===================
> > 1.1 What the group is about
>
> > This group was formed for the discussion of homebuilt computer
> > hardware, as the name implies. The term "homebuilt" or alternately,
> > "homebrew", refers to the hobby of building electronics at home,
> > generally with a soldering iron or wire wrap.
>
> > Please note: Unfortunately, the term "homebuilt" causes a great deal
> > of confusion amongst IBM clone builders, which leads to a large number
> > of inappropriate posts on this newsgroup. This group, as a general
> > rule, is not for discussion of IBM related hardware ...
> > ================================================== ===================
>
> > - Franc Zabkar
> > --
> > Please remove one 'i' from my address when replying by email.
>
> Franc,
>
> As right as you may be, I am afraid there is little discussion of
> homebrew computing done here anymore.
>
> At any rate, I received the initial prototype PCBs, fully build one
> machine, tested it, and it works per design. *The SBC boots into a
> custom monitor and will boot CP/M on demand. *There were a few design
> issues uncovered which I corrected in a new version of the PCB.
> Nothing critical but enough to warrant a respin.
>
> I recently updated the SBC CBIOS to support the full 1MB ROM as a
> block device (F. *It works great and as soon as the updated design
> finishes in the autorouter / optimizer, which will probably be several
> more days, I intend to order some additional PCBs for interested
> hobbyists.
>
> Those interested can follow along athttp://groups.google.com/group/n8vem
> or join USENET comp.os.cpm or in thehttp://www.vintage-computer.com/vcforum
> "other" category.
>
> Thanks and good luck!
>
> Andrew Lynch- Hide quoted text -
>
> - Show quoted text -
Z80 that's a blast from the passed. I built a Nascom (Z80) bassed in
the late 70s. Love to get my hands on a Nascom 2, but not found
anything yet.
On May 17, 8:46*am, Desmond <otuat...@aol.com> wrote:
> On May 12, 1:53*am, lynchaj <lync...@yahoo.com> wrote:
>
>
>
>
>
> > On May 10, 11:36*pm, Franc Zabkar <fzab...@iinternode.on.net> wrote:
>
> > > On Sat, 3 May 2008 20:40:51 -0700 (PDT), lynchaj <lync...@yahoo.com>
> > > put finger to keyboard and composed:
>
> > > >OK, well, I guess this must be the wrong USENET group to be posting on
> > > >the subject of home brew computers.
>
> > > Actually you are the only one who is on-topic.
>
> > >http://www.faqs.org/faqs/homebuilt-comp-FAQ/
>
> > > ================================================== ===================
> > > 1.1 What the group is about
>
> > > This group was formed for the discussion of homebuilt computer
> > > hardware, as the name implies. The term "homebuilt" or alternately,
> > > "homebrew", refers to the hobby of building electronics at home,
> > > generally with a soldering iron or wire wrap.
>
> > > Please note: Unfortunately, the term "homebuilt" causes a great deal
> > > of confusion amongst IBM clone builders, which leads to a large number
> > > of inappropriate posts on this newsgroup. This group, as a general
> > > rule, is not for discussion of IBM related hardware ...
> > > ================================================== ===================
>
> > > - Franc Zabkar
> > > --
> > > Please remove one 'i' from my address when replying by email.
>
> > Franc,
>
> > As right as you may be, I am afraid there is little discussion of
> > homebrew computing done here anymore.
>
> > At any rate, I received the initial prototype PCBs, fully build one
> > machine, tested it, and it works per design. *The SBC boots into a
> > custom monitor and will boot CP/M on demand. *There were a few design
> > issues uncovered which I corrected in a new version of the PCB.
> > Nothing critical but enough to warrant a respin.
>
> > I recently updated the SBC CBIOS to support the full 1MB ROM as a
> > block device (F. *It works great and as soon as the updated design
> > finishes in the autorouter / optimizer, which will probably be several
> > more days, I intend to order some additional PCBs for interested
> > hobbyists.
>
> > Those interested can follow along athttp://groups.google.com/group/n8vem
> > or join USENET comp.os.cpm or in thehttp://www.vintage-computer.com/vcforum
> > "other" category.
>
> > Thanks and good luck!
>
> > Andrew Lynch- Hide quoted text -
>
> > - Show quoted text -
>
> Z80 that's a blast from the passed. I built a Nascom (Z80) bassed in
> the late 70s. Love to get my hands on a Nascom 2, but not found
> anything yet.
>
> Desmond.- Hide quoted text -
>
> - Show quoted text -
Hi!
Nascom Z80 computers show up occasionally on Ebay, especially in the
UK where they were more popular.
Good luck with your search. You might try the CCTALK mailing list or
vintage-computers.com to see if there is anyone there who has one.
There may be.
On May 17, 10:59*am, lynchaj <lync...@yahoo.com> wrote:
> On May 17, 8:46*am, Desmond <otuat...@aol.com> wrote:
>
>
>
>
>
> > On May 12, 1:53*am, lynchaj <lync...@yahoo.com> wrote:
>
> > > On May 10, 11:36*pm, Franc Zabkar <fzab...@iinternode.on.net> wrote:
>
> > > > On Sat, 3 May 2008 20:40:51 -0700 (PDT), lynchaj <lync...@yahoo.com>
> > > > put finger to keyboard and composed:
>
> > > > >OK, well, I guess this must be the wrong USENET group to be posting on
> > > > >the subject of home brew computers.
>
> > > > Actually you are the only one who is on-topic.
>
> > > >http://www.faqs.org/faqs/homebuilt-comp-FAQ/
>
> > > > ================================================== ===================
> > > > 1.1 What the group is about
>
> > > > This group was formed for the discussion of homebuilt computer
> > > > hardware, as the name implies. The term "homebuilt" or alternately,
> > > > "homebrew", refers to the hobby of building electronics at home,
> > > > generally with a soldering iron or wire wrap.
>
> > > > Please note: Unfortunately, the term "homebuilt" causes a great deal
> > > > of confusion amongst IBM clone builders, which leads to a large number
> > > > of inappropriate posts on this newsgroup. This group, as a general
> > > > rule, is not for discussion of IBM related hardware ...
> > > > ================================================== ===================
>
> > > > - Franc Zabkar
> > > > --
> > > > Please remove one 'i' from my address when replying by email.
>
> > > Franc,
>
> > > As right as you may be, I am afraid there is little discussion of
> > > homebrew computing done here anymore.
>
> > > At any rate, I received the initial prototype PCBs, fully build one
> > > machine, tested it, and it works per design. *The SBC boots into a
> > > custom monitor and will boot CP/M on demand. *There were a few design
> > > issues uncovered which I corrected in a new version of the PCB.
> > > Nothing critical but enough to warrant a respin.
>
> > > I recently updated the SBC CBIOS to support the full 1MB ROM as a
> > > block device (F. *It works great and as soon as the updated design
> > > finishes in the autorouter / optimizer, which will probably be several
> > > more days, I intend to order some additional PCBs for interested
> > > hobbyists.
>
> > > Those interested can follow along athttp://groups.google.com/group/n8vem
> > > or join USENET comp.os.cpm or in thehttp://www.vintage-computer.com/vcforum
> > > "other" category.
>
> > > Thanks and good luck!
>
> > > Andrew Lynch- Hide quoted text -
>
> > > - Show quoted text -
>
> > Z80 that's a blast from the passed. I built a Nascom (Z80) bassed in
> > the late 70s. Love to get my hands on a Nascom 2, but not found
> > anything yet.
>
> > Desmond.- Hide quoted text -
>
> > - Show quoted text -
>
> Hi!
>
> Nascom Z80 computers show up occasionally on Ebay, especially in the
> UK where they were more popular.
>
> Good luck with your search. *You might try the CCTALK mailing list or
> vintage-computers.com to see if there is anyone there who has one.
> There may be.
>
> Thanks and have a nice day!
>
> Andrew Lynch- Hide quoted text -
>
> - Show quoted text -
Hi,
Just a quick update on this thread. The PCBs have arrived and I have
shipped a few to some builders.
I have few PCBs left if anyone is interested. If so, please join us
on the N8VEM group mentioned earlier. Thanks!
On Jun 7, 4:44*pm, lynchaj <lync...@yahoo.com> wrote:
> On May 17, 10:59*am, lynchaj <lync...@yahoo.com> wrote:
>
[snip]
>
> PS,http://groups.google.com/group/n8vem- Hide quoted text -
>
> - Show quoted text -
Hi,
The first batch of N8VEM SBC PCBs have all sold. Several people are
building their own SBCs and a couple have already completed their
projects.
Of the two that are finished, both worked on the first try which is
encouraging. The SBC is meant to be customized so there is already
some diverse styles emerging. Some are going for the old school retro
computer style while others are going high end looking to speed up the
CPU clock. I was happy just to make it work but am glad people are
adding their personal touches.
Here are some links to photos of the two completed projects:
If you are interested in really building your own home brew computer
and are willing to commit to a purchase, I have started a waiting list
for the next batch of manufactured PCBs. I have shipped PCBs to many
places. Probably half stayed in the US and the other half went
overseas to Europe, the UK, and Australia.
If and when enough people sign up to reduce my risk of a box of unsold
PCBs, I will place the order and distribute the PCBs to those on the
waiting list first. Any remaining PCBs will be available as before.
The cost of the PCB is $20 plus shipping and the details are all on
the N8VEM Google Group site. I am not accepting advanced orders or
any funds in advance, just your word that you are committed to
purchasing a PCB to get on the waiting list.
Actual implementation costs of the SBC vary. Some have been building
the PCB for practically nothing using just what they already have on
their workbench. Others are spending quite a bit by just ordering all
the parts commerically. Some are buying much better parts than they
probably really need but it is a matter of personal preference.
Others are reusing old PC and electronic scrap for parts which really
keeps the cost down. Ultimately it is up to the builder as to what
choices they make and as long as it works its fine by me.
What is really interesting is some hobbyist projects have already
sprung up such as IDE and SD readers. We'll see how they develop but
certainly they are encouraging to see.
Re: Z80 home brew project 
. It works great and as soon as the updated design
Linear Mode
