Topics

I received the 1802 Membership card #MembershipCard


Kazuhiro Ouchi
 

Hi,

I received the 1802 Membership card.
I collect parts that I don't have now.
I will assemble it when the parts are collected.

Thanks
Kazu


joshbensadon
 

Good luck on your build!


From: cosmacelf@groups.io <cosmacelf@groups.io> on behalf of Kazuhiro Ouchi <goomog@...>
Sent: Saturday, September 19, 2020 10:21 PM
To: cosmacelf@groups.io <cosmacelf@groups.io>
Subject: [cosmacelf] I received the 1802 Membership card #MembershipCard
 
Hi,

I received the 1802 Membership card.
I collect parts that I don't have now.
I will assemble it when the parts are collected.

Thanks
Kazu


Kazuhiro Ouchi
 

Hi Lee,

It worked.
It's a great board. Thank you.
https://youtu.be/2_dGH8FV8zc

Regards,
Kazu


Alan Jones
 

Good job Kazu.
I like your homebrew SIP resistors!

Alan

On Sat, 17 Oct 2020 05:23:40 -0400, Kazuhiro Ouchi <goomog@...> wrote:

Hi Lee,

It worked.
It's a great board. Thank you.
https://youtu.be/2_dGH8FV8zc

Regards,
Kazu



Lee Hart
 

Kazuhiro Ouchi wrote:
Hi Lee,

It worked.
It's a great board. Thank you.
https://youtu.be/2_dGH8FV8zc
Congratulations. You're a member of the 1802 club for a while; but now you have your membership card. :-)

Lee Hart

--
A designer knows he has achieved perfection not when there is
nothing left to add, but when there is nothing left to take away.
-- Antoine de Saint Exupery
--
Lee Hart, 814 8th Ave N, Sartell MN 56377, www.sunrise-ev.com


Kazuhiro Ouchi
 

Hi Lee,

My Membership Card works, but there was one problem. when MCSMP20J.bin was written into EEPROM 28C256, the monitor did not start inevitably.
Then, when I wrote into EPROM 27C256, it worked normally.
If you have any tips on this, please let me know.
The details are in the blog. Please use the translation site as it is in Japanese.

https://kanpapa.com/cosmac/blog/2020/10/1802-membership-card-part2.html

Regards,
Kazu


Kazuhiro Ouchi
 

It just occurred to me, but is it possible that the contents of the EEPROM may be rewritten when the Front panel is connected?

Regards,
Kazu


the-eagle@att.net
 
Edited

Kazu,

            A few years ago I ordered 10 EEPROM's (28C256) from China, they were all defective, I have tested the MCSMP20J in a 64K RAM system without error. You have to properly set the P2 and P3 memory jumpers (which is the same for a upper 32K RAM chip). Please set P2 with pin 1 to pin 2 and also pin 4 to pin 5, then also set P3 with pin 1 to pin 3 and also pin 2 to pin 4. This is on the schematic of the Membership as well. This should work for with EEPROM okay as it also works having a 32K RAM upper memory as well.

 

Regards,

Chuck Yakym

 


Lee Hart
 

Kazuhiro Ouchi wrote:
It just occurred to me, but is it possible that the contents of the
EEPROM may be rewritten when the Front panel is connected?
Yes, in fact you *can* write to an EEPROM addressed at zero with the 1802MC front panel. It will program exactly like a RAM at this address.

Also, be sure the P2 and P3 jumpers are set correctly for your EEPROM. The jumper positions are *different* for EPROMs and EEPROMs!

Lee Hart

--
A designer knows he has achieved perfection not when there is
nothing left to add, but when there is nothing left to take away.
-- Antoine de Saint Exupery
--
Lee Hart, 814 8th Ave N, Sartell MN 56377, www.sunrise-ev.com


Kazuhiro Ouchi
 

Hi Lee and Chuck,

Thank you for your comment.
I was using the TABLE 1 setting when using the 28C256 EEPROM.

P2 1-2, 4-5
P3 1-3, 2-4

I removed the 28C256 EEPROM where the MCSMP20J monitor was not working and tried to read the data and found that the data in the following two places had been rewritten to 00.

$B4FF D5 -> 00
$FFFF FF -> 00

When I installed the front panel, I thought that ~WE might be unstable and the data might be rewritten, so I tried to connect  EEPROM's ~WE to VDD.
The settings of the jumpers are as follows.

P2 1-2, 4-5
P3 1-3, 4-5

I confirmed that the MCSMP20J monitor works normally when I installed the 28C256 EEPROM and Front Panel in this condition.

This may be a hint to solve the problem that the MCSMP20J monitor does not work using EEPROM.

Regards,
Kazu


Hans Liss
 

Hi Kazu,

I had this problem with my MC using an EEPROM. I ended up having to jumper it as read-only. I'm using the same jumper settings you came up with:

P2:1-2,4-5

P3:1-3,4-5

So, the same as the manual lists for 28256, but with WE tied to Vdd.

/Hans

On 2020-10-20 13:45, Kazuhiro Ouchi wrote:
Hi Lee and Chuck,

Thank you for your comment.
I was using the TABLE 1 setting when using the 28C256 EEPROM.

P2 1-2, 4-5
P3 1-3, 2-4

I removed the 28C256 EEPROM where the MCSMP20J monitor was not working and tried to read the data and found that the data in the following two places had been rewritten to 00.

$B4FF D5 -> 00
$FFFF FF -> 00

When I installed the front panel, I thought that ~WE might be unstable and the data might be rewritten, so I tried to connect  EEPROM's ~WE to VDD.
The settings of the jumpers are as follows.

P2 1-2, 4-5
P3 1-3, 4-5

I confirmed that the MCSMP20J monitor works normally when I installed the 28C256 EEPROM and Front Panel in this condition.

This may be a hint to solve the problem that the MCSMP20J monitor does not work using EEPROM.

Regards,
Kazu


Kazuhiro Ouchi
 

Hi Hans,

Thank you for your comment.
I was relieved to see that we are using the same setup.
I've been thinking about it in the bath, but most of the binaries are match, and it's hard to imagine the monitor program not working at all just because the last byte of memory was rewritten.
It occurred to me that if the monitor's initialization routine was trying to identify the memory map by writing to the last byte of memory, it might be working in a way that was not expected.

Regards,
Kazu


Hans Liss
 

Hi Kazu,

Yes, that was my conclusion as well. I reported this on the list on Mar 19. Chuck said that the monitor will start at $FFFF and search downwards to look for useable RAM memory, even when the monitor is located at $8000. I guess this might be difficult to change in the monitor code, but maybe a footnote in the MC manual would be helpful:

"If you are running the MCSMP monitor from a 28256 EEPROM at $8000, set P3 to 1-3,4-5 instead of 1-3,2-4."

/Hans

On 2020-10-20 14:37, Kazuhiro Ouchi wrote:
Hi Hans,

Thank you for your comment.
I was relieved to see that we are using the same setup.
I've been thinking about it in the bath, but most of the binaries are match, and it's hard to imagine the monitor program not working at all just because the last byte of memory was rewritten.
It occurred to me that if the monitor's initialization routine was trying to identify the memory map by writing to the last byte of memory, it might be working in a way that was not expected.

Regards,
Kazu


Kazuhiro Ouchi
 

Hi Hans,

Thank you for the good information.
Now that's a mystery solved!
I'm very happy.

Regards,
Kazu


Hans Liss
 

Have fun with the MC! I'm contemplating buying another kit, just because it was so much fun to build. :)

/Hans

On 2020-10-20 14:47, Kazuhiro Ouchi wrote:
Hi Hans,

Thank you for the good information.
Now that's a mystery solved!
I'm very happy.

Regards,
Kazu


Kazuhiro Ouchi
 

Hi Alan,

Yes. I use this method a lot.
It doesn't look good, though.

Regards,
Kazu


COSTAS SKORDIS
 

Agree Hans, 

Building the MC was most enjoyable.

On Oct 20, 2020, at 7:49 AM, Hans Liss <Hans@...> wrote:



Have fun with the MC! I'm contemplating buying another kit, just because it was so much fun to build. :)

/Hans

On 2020-10-20 14:47, Kazuhiro Ouchi wrote:
Hi Hans,

Thank you for the good information.
Now that's a mystery solved!
I'm very happy.

Regards,
Kazu