[N8VEM: 16954] N8-2312 fixed SD card interface and RTC

Discussion:

Arlen

2014-01-03 02:39:37 UTC

I'm continuing to test and debug my N8-2312 with RomWBW 2.5.2.

ROM drive, RAM drive, and floppy have all been working well. But the SD
interface was not working at all.

I started with the SD card socket, since this has been problematic for a
few builders. I am using a known-good part number (TE Connectivity
2041021-4) and my novice smd soldering seemed good enough. So I pulled out
the voltmeter. The "SD-howto" note helped me recognize a suspiciously low
0.47v on SD pin 1. Tracing back, I eventually saw that I had an
out-of-spec BUF_02 signal, caused by a faulty 74LS574 (U11). When I
replaced U11 the SD interface started working immediately.

The RTC also relies on U11, which explains why the RTC.COM test program had
not been responding sensibly either.

It's always nice to fix two problems for the price of one.

Arlen Michaels

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Rich Cini

2014-01-03 04:31:07 UTC

Permalink

Arlen - this is good stuff. As a result of your work I looked at my build and I discovered that I substituted 4.7 ohm and 2.7 ohm resistors for the 4.7k and 2.7k. Oops. I guess I need better glasses!

Although I made this repair, the SD card still doesn't work. What are the specs of the SD card you are using (size and format)? I've been using a Kingston 512mb card that I formatted as both FAT and FAT32.

Did you make any other changes to the ROM?

Rich Cini
Sent from my iPhone

Post by Arlen
I'm continuing to test and debug my N8-2312 with RomWBW 2.5.2.
ROM drive, RAM drive, and floppy have all been working well. But the SD interface was not working at all.
I started with the SD card socket, since this has been problematic for a few builders. I am using a known-good part number (TE Connectivity 2041021-4) and my novice smd soldering seemed good enough. So I pulled out the voltmeter. The "SD-howto" note helped me recognize a suspiciously low 0.47v on SD pin 1. Tracing back, I eventually saw that I had an out-of-spec BUF_02 signal, caused by a faulty 74LS574 (U11). When I replaced U11 the SD interface started working immediately.
The RTC also relies on U11, which explains why the RTC.COM test program had not been responding sensibly either.
It's always nice to fix two problems for the price of one.
Arlen Michaels
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Arlen

2014-01-03 17:40:10 UTC

Permalink

Rich,

You want to be really careful about the SD circuit because with any error
there's a risk of putting 5v on the SD socket pins instead of 3.3v. So I
suggest you patiently check the voltage at every pin before plugging in
cards. Also, some SD card sockets have pinouts that don't match the pcb
layout, so that's an obvious source of trouble.

You might find this little extender board for the SD socket useful:
http://www.sparkfun.com/products/11468. I used one and it gave me more
confidence that my socket pin-outs and its surface mount soldered
connections were good.

I've been using a junk no-name SD card labelled "Super Talent 2GB" (love
those bizarre Chinese brand names!) without any problems. No changes to
the standard ROM were needed. You'll notice that the standard 2312
configuration file specifies the SD capacity as 64 MB, which is fine; it
simply creates four cp/m drives on the SD card using a fraction of the true
capacity of the card, but this is fine for testing that everything works.
Later I did change the configuration file's SD capacity setting to (232*9)
MB, built a new ROM, and used MULTIFMT.COM to initialize all 232 LUs of
storage on this 2 GB card. btw, it takes many minutes for MULTIFMT to
initialize all 232 LUs on a 2GB card.

Arlen Michaels

Post by Rich Cini
Arlen - this is good stuff. As a result of your work I looked at my build
and I discovered that I substituted 4.7 ohm and 2.7 ohm resistors for the
4.7k and 2.7k. Oops. I guess I need better glasses!
Although I made this repair, the SD card still doesn't work. What are the
specs of the SD card you are using (size and format)? I've been using a
Kingston 512mb card that I formatted as both FAT and FAT32.
Did you make any other changes to the ROM?
Rich Cini
Sent from my iPhone
I'm continuing to test and debug my N8-2312 with RomWBW 2.5.2.
ROM drive, RAM drive, and floppy have all been working well. But the SD
interface was not working at all.
I started with the SD card socket, since this has been problematic for a
few builders. I am using a known-good part number (TE Connectivity
2041021-4) and my novice smd soldering seemed good enough. So I pulled out
the voltmeter. The "SD-howto" note helped me recognize a suspiciously low
0.47v on SD pin 1. Tracing back, I eventually saw that I had an
out-of-spec BUF_02 signal, caused by a faulty 74LS574 (U11). When I
replaced U11 the SD interface started working immediately.
The RTC also relies on U11, which explains why the RTC.COM test program
had not been responding sensibly either.
It's always nice to fix two problems for the price of one.
Arlen Michaels
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Rich Cini

2014-01-03 18:50:38 UTC

Permalink

Arlen -- it's amazing what the right resistors will do! I rebuilt the rom with the PPIDE change (for consistency) and gave it a try. The N8 fully recognizes the card. I formatted 4 partitions and made the first bootable. Yea! It works.

The only thing I should fix is making the floppy "optional". It won't boot if the floppy drive isn't connected. Quick fix I'm sure.

Rich Cini
Sent from my iPhone

Rich,
You want to be really careful about the SD circuit because with any error there's a risk of putting 5v on the SD socket pins instead of 3.3v. So I suggest you patiently check the voltage at every pin before plugging in cards. Also, some SD card sockets have pinouts that don't match the pcb layout, so that's an obvious source of trouble.
You might find this little extender board for the SD socket useful: http://www.sparkfun.com/products/11468. I used one and it gave me more confidence that my socket pin-outs and its surface mount soldered connections were good.
I've been using a junk no-name SD card labelled "Super Talent 2GB" (love those bizarre Chinese brand names!) without any problems. No changes to the standard ROM were needed. You'll notice that the standard 2312 configuration file specifies the SD capacity as 64 MB, which is fine; it simply creates four cp/m drives on the SD card using a fraction of the true capacity of the card, but this is fine for testing that everything works. Later I did change the configuration file's SD capacity setting to (232*9) MB, built a new ROM, and used MULTIFMT.COM to initialize all 232 LUs of storage on this 2 GB card. btw, it takes many minutes for MULTIFMT to initialize all 232 LUs on a 2GB card.
Arlen Michaels

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Arlen

2014-01-03 23:29:04 UTC

Permalink

Congratulations, Rich!

I'm still trying to wrap my head around the reality of having what is
effectively an "infinite" amount of storage for CP/M!

Nice.

Arlen Michaels

Post by Rich Cini
Arlen -- it's amazing what the right resistors will do! I rebuilt the rom
with the PPIDE change (for consistency) and gave it a try. The N8 fully
recognizes the card. I formatted 4 partitions and made the first bootable.
Yea! It works.
The only thing I should fix is making the floppy "optional". It won't boot
if the floppy drive isn't connected. Quick fix I'm sure.
Rich Cini
Sent from my iPhone
Rich,
You want to be really careful about the SD circuit because with any error
there's a risk of putting 5v on the SD socket pins instead of 3.3v. So I
suggest you patiently check the voltage at every pin before plugging in
cards. Also, some SD card sockets have pinouts that don't match the pcb
layout, so that's an obvious source of trouble.
http://www.sparkfun.com/products/11468. I used one and it gave me more
confidence that my socket pin-outs and its surface mount soldered
connections were good.
I've been using a junk no-name SD card labelled "Super Talent 2GB" (love
those bizarre Chinese brand names!) without any problems. No changes to
the standard ROM were needed. You'll notice that the standard 2312
configuration file specifies the SD capacity as 64 MB, which is fine; it
simply creates four cp/m drives on the SD card using a fraction of the true
capacity of the card, but this is fine for testing that everything works.
Later I did change the configuration file's SD capacity setting to (232*9)
MB, built a new ROM, and used MULTIFMT.COM to initialize all 232 LUs of
storage on this 2 GB card. btw, it takes many minutes for MULTIFMT to
initialize all 232 LUs on a 2GB card.
Arlen Michaels

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douglas_goodall

2014-01-04 09:08:18 UTC

Permalink

Arlen,

I am so with you there. Having a 2GB chip and over 200 logical units is
awesome and bodacious (as Po would say).

Being able to save an image of the 2GB chip with the Windows imaging
program makes it painless to back up the
nearly infinite storage as well. If you back up an LU you are using for
development every day, you can do that for
about eight months before you run short. The ability to label the LU's is
sweet as well.

I am glad you are enjoying the LU support :-)

Happy New Year everyone, Douglas Goodall

Post by Arlen
Congratulations, Rich!
I'm still trying to wrap my head around the reality of having what is
effectively an "infinite" amount of storage for CP/M!
Nice.
Arlen Michaels

Post by Rich Cini
Arlen -- it's amazing what the right resistors will do! I rebuilt the rom
with the PPIDE change (for consistency) and gave it a try. The N8 fully
recognizes the card. I formatted 4 partitions and made the first bootable.
Yea! It works.
The only thing I should fix is making the floppy "optional". It won't
boot if the floppy drive isn't connected. Quick fix I'm sure.
Rich Cini
Sent from my iPhone
Rich,
You want to be really careful about the SD circuit because with any error
there's a risk of putting 5v on the SD socket pins instead of 3.3v. So I
suggest you patiently check the voltage at every pin before plugging in
cards. Also, some SD card sockets have pinouts that don't match the pcb
layout, so that's an obvious source of trouble.
http://www.sparkfun.com/products/11468. I used one and it gave me more
confidence that my socket pin-outs and its surface mount soldered
connections were good.
I've been using a junk no-name SD card labelled "Super Talent 2GB" (love
those bizarre Chinese brand names!) without any problems. No changes to
the standard ROM were needed. You'll notice that the standard 2312
configuration file specifies the SD capacity as 64 MB, which is fine; it
simply creates four cp/m drives on the SD card using a fraction of the true
capacity of the card, but this is fine for testing that everything works.
Later I did change the configuration file's SD capacity setting to (232*9)
MB, built a new ROM, and used MULTIFMT.COM to initialize all 232 LUs of
storage on this 2 GB card. btw, it takes many minutes for MULTIFMT to
initialize all 232 LUs on a 2GB card.
Arlen Michaels

Post by Rich Cini
Arlen - this is good stuff. As a result of your work I looked at my
build and I discovered that I substituted 4.7 ohm and 2.7 ohm resistors for
the 4.7k and 2.7k. Oops. I guess I need better glasses!
Although I made this repair, the SD card still doesn't work. What are
the specs of the SD card you are using (size and format)? I've been using a
Kingston 512mb card that I formatted as both FAT and FAT32.
Did you make any other changes to the ROM?
Rich Cini
Sent from my iPhone
I'm continuing to test and debug my N8-2312 with RomWBW 2.5.2.
ROM drive, RAM drive, and floppy have all been working well. But the SD
interface was not working at all.
I started with the SD card socket, since this has been problematic for a
few builders. I am using a known-good part number (TE Connectivity
2041021-4) and my novice smd soldering seemed good enough. So I pulled out
the voltmeter. The "SD-howto" note helped me recognize a suspiciously low
0.47v on SD pin 1. Tracing back, I eventually saw that I had an
out-of-spec BUF_02 signal, caused by a faulty 74LS574 (U11). When I
replaced U11 the SD interface started working immediately.
The RTC also relies on U11, which explains why the RTC.COM test program
had not been responding sensibly either.
It's always nice to fix two problems for the price of one.
Arlen Michaels
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douglas_goodall

2014-01-04 09:15:11 UTC

Permalink

Arlen,

It is a pleasure to see you using MULTIFMT. It is my favorite of all the
utilities I wrote. It really tries to keep you from shooting yourself in
the foot.

It does take some time to format 232 LU's, but it does do a lot of work. In
addition to formatting the directory, it initializes the metadata. Take the
time
to learn to use the META utility as protecting LU's is handy.

Douglas

Post by Arlen
Rich,
You want to be really careful about the SD circuit because with any error
there's a risk of putting 5v on the SD socket pins instead of 3.3v. So I
suggest you patiently check the voltage at every pin before plugging in
cards. Also, some SD card sockets have pinouts that don't match the pcb
layout, so that's an obvious source of trouble.
http://www.sparkfun.com/products/11468. I used one and it gave me more
confidence that my socket pin-outs and its surface mount soldered
connections were good.
I've been using a junk no-name SD card labelled "Super Talent 2GB" (love
those bizarre Chinese brand names!) without any problems. No changes to
the standard ROM were needed. You'll notice that the standard 2312
configuration file specifies the SD capacity as 64 MB, which is fine; it
simply creates four cp/m drives on the SD card using a fraction of the true
capacity of the card, but this is fine for testing that everything works.
Later I did change the configuration file's SD capacity setting to (232*9)
MB, built a new ROM, and used MULTIFMT.COM to initialize all 232 LUs of
storage on this 2 GB card. btw, it takes many minutes for MULTIFMT to
initialize all 232 LUs on a 2GB card.
Arlen Michaels

Arlen

2014-01-05 19:46:31 UTC

Permalink

I agree! MULTIFMT and META are elegant and invaluable tools.

Their benefit is really proven when you also implement the Windows cp/m
file system driver "cpmcbfs", as Oscar has pointed out
(https://groups.google.com/forum/?hl=en&fromgroups#!topic/n8vem/l-7Z3_ZawWI).
It then becomes easy to move lots of software around and fully exploit
those LUs.

Arlen Michaels

Post by douglas_goodall
Arlen,
It is a pleasure to see you using MULTIFMT. It is my favorite of all the
utilities I wrote. It really tries to keep you from shooting yourself in
the foot.
It does take some time to format 232 LU's, but it does do a lot of work.
In addition to formatting the directory, it initializes the metadata. Take
the time
to learn to use the META utility as protecting LU's is handy.
Douglas

Post by Rich Cini
Arlen - this is good stuff. As a result of your work I looked at my
build and I discovered that I substituted 4.7 ohm and 2.7 ohm resistors for
the 4.7k and 2.7k. Oops. I guess I need better glasses!
Although I made this repair, the SD card still doesn't work. What are
the specs of the SD card you are using (size and format)? I've been using a
Kingston 512mb card that I formatted as both FAT and FAT32.
Did you make any other changes to the ROM?
Rich Cini
Sent from my iPhone
I'm continuing to test and debug my N8-2312 with RomWBW 2.5.2.
ROM drive, RAM drive, and floppy have all been working well. But the SD
interface was not working at all.
I started with the SD card socket, since this has been problematic for a
few builders. I am using a known-good part number (TE Connectivity
2041021-4) and my novice smd soldering seemed good enough. So I pulled out
the voltmeter. The "SD-howto" note helped me recognize a suspiciously low
0.47v on SD pin 1. Tracing back, I eventually saw that I had an
out-of-spec BUF_02 signal, caused by a faulty 74LS574 (U11). When I
replaced U11 the SD interface started working immediately.
The RTC also relies on U11, which explains why the RTC.COM test program
had not been responding sensibly either.
It's always nice to fix two problems for the price of one.
Arlen Michaels
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