[N8VEM: 16738] New Zeta Build Pics

[Andrew Bingham]

Well, I received my parts from Mouser and my PCBs from Sergey, so here we
go.

Pictures attached.

I ended up not having exactly the right 5V barrely plug supply so I'll get
that today and try and boot it up tonight.

I'll also be building the ParPortProp board soon as well.

Andrew

[Jim Strickland]

Nice job.

A couple things from my own build:

If that Zeta was mine, I'd give the parallel connector the once over for solder bridges. What I'm seeing is /probably/ flux (hard to tell in the picture) but better safe than sorry.

You're aware the Zeta won't boot without the battery installed, right?

Do you know what clock speed your 82c55AC is rated at? It needs to be 1/2 CPU speed, apparently. (I can't read your u21 oscillator's frequency, so this may not be an issue.) I've read on here that one can put an extra wait state in the 8255's driver code and solve this problem in software. (Wayne et al's bios code is a joy to read, even if you've not dealt with assembler before. Shouldn't be too bad.) You won't notice the 82c55's problems - if any - until you try to boot the PPP rom image.

Finally, prior to first powerup, others have recommended putting your VOM across the the Zeta's power terminals and checking resistance. It should be pretty high - the zeta doesn't draw much current.

Feel your chips when you plug in. If you had an FDC, it would be far and way the warmest chip, but nothing should be too hot to touch.

Terminal at 38400, 8n1, flow control off, and set carrier-watch off if you're using kermit to talk to the zeta. Also, you need a null modem, most likely. PC rs232 ports (including the USB dongle type) and the Zeta's rs232 ports are wired the same way.

Good luck and please let us know how it goes. :)

-JRS
(new Zeta owner, currently at 10mhz)

[Andrew Bingham]

Well, I just spent the better part of an hour with a hand-soldered null
modem cable trying to get my Zeta up and running....*without* the battery.

So now I'll go steal a battery from a recently-deceased PC motherboard and
try again.

Thanks for the tips! I did give everything a good once over with a
magnifying glass before I plugged it in. I didn't have any alcohol handy
to clean up the flux. Soldering is one of my least favorite things in the
world so this project is a pretty big deal. (Mostly because my desire to
play with homebrew PCs outstrips how much I dislike soldering). I did buy
myself a nice Weller digital station which greatly improved my experience
over past experiences, so clearly good equipment makes a difference.

I picked up a Vector Graphic MZ from a coworker with what should be a
functional set of boards (Z80, 64KB RAM, Flashwriter II, FDC Controller)
and plenty of free slots for more S-100 cards, so this Zeta is just a
start.....

Andrew

Post by Jim Strickland
Nice job.
If that Zeta was mine, I'd give the parallel connector the once over for
solder bridges. What I'm seeing is /probably/ flux (hard to tell in the
picture) but better safe than sorry.
You're aware the Zeta won't boot without the battery installed, right?
Do you know what clock speed your 82c55AC is rated at? It needs to be 1/2
CPU speed, apparently. (I can't read your u21 oscillator's frequency, so
this may not be an issue.) I've read on here that one can put an extra wait
state in the 8255's driver code and solve this problem in software. (Wayne
et al's bios code is a joy to read, even if you've not dealt with assembler
before. Shouldn't be too bad.) You won't notice the 82c55's problems - if
any - until you try to boot the PPP rom image.
Finally, prior to first powerup, others have recommended putting your VOM
across the the Zeta's power terminals and checking resistance. It should be
pretty high - the zeta doesn't draw much current.
Feel your chips when you plug in. If you had an FDC, it would be far and
way the warmest chip, but nothing should be too hot to touch.
Terminal at 38400, 8n1, flow control off, and set carrier-watch off if
you're using kermit to talk to the zeta. Also, you need a null modem, most
likely. PC rs232 ports (including the USB dongle type) and the Zeta's rs232
ports are wired the same way.
Good luck and please let us know how it goes. :)
-JRS
(new Zeta owner, currently at 10mhz)

[Jim Strickland]

Isn't it funny how you just wind up accumulating Z80 machines once you mention an interest in them? I wound up with an Ampro Littleboard that way along with two fully functional Tandon full height 5.25 inch drives straight out of an original PC. Boots right up off 30 year old media. :) (I've made a new boot disk since then.)
-JRS

[Andrew Bingham]

So, even with a battery (from a ~2 year old motherboard, I'll get some new
batteries tomorrow), I'm not getting anything out of the serial terminal on
this board. I also notice that none of the ICs are getting even a little
bit warm, they are all cool/room temperature to the touch. Which seems
strange.

I've ordered a real null modem cable from Amazon, but until I get that - I
do have one of the Open Bench Logic Sniffers - are there some basic points
I can probe to make sure that the appropriate clocks are making it out onto
the board, etc?

Should I be seeing any output from the bottom LED at all to tell me this
thing is doing something? I guess I'm used to more blinkenlights.

Andrew

Post by Jim Strickland
Isn't it funny how you just wind up accumulating Z80 machines once you
mention an interest in them? I wound up with an Ampro Littleboard that way
along with two fully functional Tandon full height 5.25 inch drives
straight out of an original PC. Boots right up off 30 year old media. :)
(I've made a new boot disk since then.)
-JRS

[Jim Strickland]

The bottom light(halt) will sometimes come on when the board hangs, but otherwise doesn't usually have much to say.

The usual advice is to pull all the ics and check for power and ground on each socket.

You can also hook your logic sniffer to the cpu's clock line, chip select on the ram and rom, and if you have more channels, some address or data lines .

Pull the jumper off fd interrupt/nmi, too. That can cause confusion.

However, I would really suspect your term software and/or serial cabling. Rs232 is /fussy/. Make sure your term software has no flow control at all, as the zeta doesn't do any by default.

If everything else looks good, check the inputs and outputs on the 16550.

I assume you put the zeta std rom file in your flash rom. The PPP one won't boot without the PPP installed.

-JRS

[Jim Strickland]

Oh yeah. You're hitting the reset button during boot attempts. Right?

[Sergey]

Good job.

Newer RomWBW/PPP firmware (versions 2.0+ or so) will use serial port for
console if JP1/CONFIG jumper is closed. This allows using Zeta without PPP.
I've updated Zeta documentation page accordingly.

Troubleshooting:
- Visually inspect the board. I suggest cleaning the flux, as it can cover
some solder bridges, or cold joints.
- Measure voltage on ICs (note not all ICs have ground/VCC on the last pin
in the row, some like Z80 have them elsewhere... check datasheets).
- Good method to test the serial connection and MAX232 level converters is
to extract 16550 and short its TX and RX pins (on the socket)... and then
try typing something in the terminal. You should be getting an echo.

[Andrew Bingham]

Tonight I made a few changes:
-Went through a pile of old CR2032 cells and found one that was still at 3V
-Swapped out the "angular style" CR2032 holder for one of the nicer "round
style" ones, repurposed off a dead PC motherboard (I snapped the plastic
catch that held the battery off the "angular" style one - when I soldered
it in, the leaf spring that held the battery in wasn't flush with the
bottom and the battery got stuck - after looking at the design I decided
the "round style" ones are much nicer to use. I tried to save like $1 on
this part when I chose between the 2 Mouser Parth #'s. I highly recommend
the round ones)
-Jumpered JP1 "CONFIG" as suggested by Sergey (using a jumper from the same
dead motherboard as the battery holder)
-Dug out a Windows XP laptop, to use my junky Prolific chipset USB->Serial
with that has driver issues with all of my Window 7/8 computers

And the verdict is.....it's alllliiiveee! Well, kind of. In HyperTerminal
I can see the boot ROM code go by, then it boots ZDOS, then....gibberish
happens. See this pastebin: http://pastebin.com/jSVncJrJ

I've got the ParPortProp board BOM on the way from Mouser and a new FTDI
chipset USB->Serial and a not-hand-soldered null modem cable coming
tomorrow (maybe that will help with the gibberish?), so I should have
everything squared away before I head off for my holiday vacation on the
23rd.

I'm just happy to see that it is running some kind of code and doing things
that I expect it to do.

Andrew

Post by Sergey
Good job.
Newer RomWBW/PPP firmware (versions 2.0+ or so) will use serial port for
console if JP1/CONFIG jumper is closed. This allows using Zeta without PPP.
I've updated Zeta documentation page accordingly.
- Visually inspect the board. I suggest cleaning the flux, as it can cover
some solder bridges, or cold joints.
- Measure voltage on ICs (note not all ICs have ground/VCC on the last pin
in the row, some like Z80 have them elsewhere... check datasheets).
- Good method to test the serial connection and MAX232 level converters is
to extract 16550 and short its TX and RX pins (on the socket)... and then
try typing something in the terminal. You should be getting an echo.

[Jim Strickland]

Post by Andrew Bingham
-Went through a pile of old CR2032 cells and found one that was still at 3V
-Swapped out the "angular style" CR2032 holder for one of the nicer "round
style" ones, repurposed off a dead PC motherboard (I snapped the plastic
catch that held the battery off the "angular" style one - when I soldered
it in, the leaf spring that held the battery in wasn't flush with the
bottom and the battery got stuck - after looking at the design I decided
the "round style" ones are much nicer to use. I tried to save like $1 on
this part when I chose between the 2 Mouser Parth #'s. I highly recommend
the round ones)
-Jumpered JP1 "CONFIG" as suggested by Sergey (using a jumper from the
same dead motherboard as the battery holder)
-Dug out a Windows XP laptop, to use my junky Prolific chipset USB->Serial
with that has driver issues with all of my Window 7/8 computers
And the verdict is.....it's alllliiiveee! Well, kind of. In
HyperTerminal I can see the boot ROM code go by, then it boots ZDOS,
http://pastebin.com/jSVncJrJ<http://www.google.com/url?q=http%3A%2F%2Fpastebin.com%2FjSVncJrJ&sa=D&sntz=1&usg=AFQjCNFw7XQxJRZuUPMaiGmGDDIvMfmVDg>
I've got the ParPortProp board BOM on the way from Mouser and a new FTDI
chipset USB->Serial and a not-hand-soldered null modem cable coming
tomorrow (maybe that will help with the gibberish?), so I should have
everything squared away before I head off for my holiday vacation on the
23rd.
I'm just happy to see that it is running some kind of code and doing
things that I expect it to do.
Andrew

Post by Sergey
Good job.
Newer RomWBW/PPP firmware (versions 2.0+ or so) will use serial port for
console if JP1/CONFIG jumper is closed. This allows using Zeta without PPP.
I've updated Zeta documentation page accordingly.
- Visually inspect the board. I suggest cleaning the flux, as it can
cover some solder bridges, or cold joints.
- Measure voltage on ICs (note not all ICs have ground/VCC on the last
pin in the row, some like Z80 have them elsewhere... check datasheets).
- Good method to test the serial connection and MAX232 level converters
is to extract 16550 and short its TX and RX pins (on the socket)... and
then try typing something in the terminal. You should be getting an echo.

Yeah, you want the RomWBW version of the rom. The Wiki's a little confusing
about that, but WBW 2.5.2 seems to be the latest and is the version I'm
running on my Zeta. It's here:
http://n8vem-sbc.pbworks.com/w/browse/#view=ViewFolder&param=RomWBW - just
grab the whole zip file, unzip it, go to the output directory, and scroll
down until you find one of the ones prefixed with Zeta. I'm using the
zsystem ppp one personally. I'd suggest using the non-ppp one until you get
your PPP put together, but contrary to what I said earlier, the ppp version
/will/ boot without the ppp present if JP1 is set, like Sergey said above.
I just wasn't waiting long enough.

You'll like the PPP. Having disk space is lovely. Make sure to load the
PPP's flash chip too. I did it with my rom burner, but apparently you can
program it from the serial port, or with the propeller cable (sold
separately.)

When you set up the ppp: make sure that jp2 is set to pins 1 and 2,
grounding pin 25. I had mine the other way, and it doesn't work. PPP is not
PPIDE.(I'm probably lucky I didn't fry something that way. It's a
surprisingly robust little machine.)

Oh, when logic sniffing the Z80, remember that the lines are almost all
active low. That threw me the first time I saw it. :)

-JRS

[Andrew Bingham]

Today I received my new FTDI-based USB->Serial adapter, and a real null
modem cable. This has cleared up the gibberish from last night and I can
now boot from the board ROM and get to a CP/M prompt. So things are
looking very good indeed!

Now - what kind of fun old CP/M software is there out there? And how can I
transfer it over (XM.COM?)

Andrew

Post by Jim Strickland

Post by Andrew Bingham
-Went through a pile of old CR2032 cells and found one that was still at 3V
-Swapped out the "angular style" CR2032 holder for one of the nicer
"round style" ones, repurposed off a dead PC motherboard (I snapped the
plastic catch that held the battery off the "angular" style one - when I
soldered it in, the leaf spring that held the battery in wasn't flush with
the bottom and the battery got stuck - after looking at the design I
decided the "round style" ones are much nicer to use. I tried to save like
$1 on this part when I chose between the 2 Mouser Parth #'s. I highly
recommend the round ones)
-Jumpered JP1 "CONFIG" as suggested by Sergey (using a jumper from the
same dead motherboard as the battery holder)
-Dug out a Windows XP laptop, to use my junky Prolific chipset
USB->Serial with that has driver issues with all of my Window 7/8 computers
And the verdict is.....it's alllliiiveee! Well, kind of. In
HyperTerminal I can see the boot ROM code go by, then it boots ZDOS,
http://pastebin.com/jSVncJrJ<http://www.google.com/url?q=http%3A%2F%2Fpastebin.com%2FjSVncJrJ&sa=D&sntz=1&usg=AFQjCNFw7XQxJRZuUPMaiGmGDDIvMfmVDg>
I've got the ParPortProp board BOM on the way from Mouser and a new FTDI
chipset USB->Serial and a not-hand-soldered null modem cable coming
tomorrow (maybe that will help with the gibberish?), so I should have
everything squared away before I head off for my holiday vacation on the
23rd.
I'm just happy to see that it is running some kind of code and doing
things that I expect it to do.
Andrew

Post by Sergey
Good job.
Newer RomWBW/PPP firmware (versions 2.0+ or so) will use serial port for
console if JP1/CONFIG jumper is closed. This allows using Zeta without PPP.
I've updated Zeta documentation page accordingly.
- Visually inspect the board. I suggest cleaning the flux, as it can
cover some solder bridges, or cold joints.
- Measure voltage on ICs (note not all ICs have ground/VCC on the last
pin in the row, some like Z80 have them elsewhere... check datasheets).
- Good method to test the serial connection and MAX232 level converters
is to extract 16550 and short its TX and RX pins (on the socket)... and
then try typing something in the terminal. You should be getting an echo.

Yeah, you want the RomWBW version of the rom. The Wiki's a little
confusing about that, but WBW 2.5.2 seems to be the latest and is the
http://n8vem-sbc.pbworks.com/w/browse/#view=ViewFolder&param=RomWBW -
just grab the whole zip file, unzip it, go to the output directory, and
scroll down until you find one of the ones prefixed with Zeta. I'm using
the zsystem ppp one personally. I'd suggest using the non-ppp one until you
get your PPP put together, but contrary to what I said earlier, the ppp
version /will/ boot without the ppp present if JP1 is set, like Sergey said
above. I just wasn't waiting long enough.
You'll like the PPP. Having disk space is lovely. Make sure to load the
PPP's flash chip too. I did it with my rom burner, but apparently you can
program it from the serial port, or with the propeller cable (sold
separately.)
When you set up the ppp: make sure that jp2 is set to pins 1 and 2,
grounding pin 25. I had mine the other way, and it doesn't work. PPP is not
PPIDE.(I'm probably lucky I didn't fry something that way. It's a
surprisingly robust little machine.)
Oh, when logic sniffing the Z80, remember that the lines are almost all
active low. That threw me the first time I saw it. :)
-JRS

[Jim Strickland]

Switch to a drive you have write access on - a for ramdrive c for floppy 1 e and beyond for sd card when your PPP is done. Then type b:xm rc <file name>

Xm is for xmodem and your terminal sw hopefully speaks it.

-JRS

[Jim Strickland]

Gamewise, the Zork trilogy is out there, all the games from Basic Computer games are out there (in BASIC, obviously, but you actually MS basic already in the rom files). Wordstar is out there, but if you search the n8vem group you can find a link to a version that's already tweaked to run on N8/Zeta. (Do grab the rest of a Wordstar archive and copy it in. There are tools that are nice to have.) Turbo pascal is out there, several different C compilers including one that is both ansi and cpm hosted. Its a treasure trove of software out there, really. Documentation can be a little thin, but hey, if you wanted it easy, you'd use a mac/windows pc. :)

About the only catch is that a lot of the stuff is zipped with more modern versions of zip than are available in CP/M. I installed ARC on my linux machines and now I can unzip with modern zip, then arc it up, xmodem it across, unarc it, and usually that's all it takes. If you wind up with one big file with an LBR extention, NULU is the tool you want. Cross platform compatibility can be ... interesting.

Once you get some disk space (Floppy or PPP) I suggest going into the RomWBW folder and into the ***_1024KB directory that matches your installed rom image. Arc that up and download it onto the zeta, then pip the entire contents of b: on top of it. Also grab all the WS*.* stuff and VIDATT.Z80 from the CPM_1024KB romdisk if you're running zsystem. That's WordStar, arguably the first wordprocessor ever.

I put the whole shmutz on an HD floppy for safe keeping. (I know, I know... SD cards are much more safe, until you consider the monkey at the keyboard (me) who likes his disk access fast even if he does want to hear a floppy drive grunt now and then. :)

All kinds of software is indexed here: http://www.classiccmp.org/cpmarchives/index.php.

Have fun. :)

-JRS

[Jim Strickland]

Gamewise, the Zork trilogy is out there, all the games from Basic Computer games are out there (in BASIC, obviously, but you actually MS basic already in the rom files). Turbo pascal is out there, several different C compilers including one that is both ansi and cp/m hosted. Its a treasure trove of software out there, really. Documentation can be a little thin, but hey, if you wanted it easy, you'd use a mac/windows pc. :)
About the only catch is that a lot of the stuff is zipped with more modern versions of zip than are available in CP/M. I installed ARC on my linux machines and now I can unzip with modern zip, then arc it up, xmodem it across, unarc it, and usually that's all it takes. If you wind up with one big file with an LBR extention, NULU is the tool you want. Cross platform compatibility can be ... interesting.

Once you get some disk space (Floppy or PPP) I suggest going into the RomWBW folder and into the ***_1024KB directory that matches your installed rom image. Arc that up and download it onto the zeta, then pip the entire contents of b: on top of it. Also grab all the WS*.* stuff and VIDATT.Z80 from the CPM_1024KB romdisk if you're running zsystem. That's WordStar, arguably the first wordprocessor ever.

I put the whole shmutz on an HD floppy for safe keeping. (I know, I know... SD cards are much more safe, until you consider the monkey at the keyboard (me) who likes his disk access fast even if he does want to hear a floppy drive grunt now and then. :)

All kinds of software is indexed here: http://www.classiccmp.org/cpmarchives/index.php.

Have fun. :)

-JRS

[oscarv]

Hi,

WRT available software, you can also have a look at my page (link<http://obsolescence.wix.com/obsolescence#!n8vemimage/c1v04>)
for the N8VEM demodisk I cooked up. It has most, but not all, of the famous
CP/M software on it.

If you have a CF/SD card and RomWBW, the download button on that page to
the actual disk image is useful.
As long as you're working on the RAM disk only, the fourth download button
has all the files in a DOS directory for uploading to the N8VEM via XModem.
Nice thing is that everything is preconfigured for VT-100.

Recommendations for software to be added are welcome!

Regards,

Oscar.

[Andrew Bingham]

I had to switch from Putty to TeraTerm, but once I did that XMing over
things was easy as pie.

Now I just need to get some storage. My FDC chip is still on its way from
China, so I think I'll have to build up the ParPortProp board to solve that
issue.

Andrew

Post by Jim Strickland
Switch to a drive you have write access on - a for ramdrive c for floppy 1
e and beyond for sd card when your PPP is done. Then type b:xm rc <file
name>
Xm is for xmodem and your terminal sw hopefully speaks it.
-JRS