The Dan ][ SD card disk controller

dabone wrote:

CVT wrote:

dabone wrote:

Ok, how about this for 28cXX support?

 

It's pin 27 that the problem,  it's actually A14 on 27256s and 27512s, but the 28c series uses it as the write enable pin.

So for proper address decoding on standard eproms, this pin should be held low, but on the 28c series it needs to be held hig

 

The original design only went as high as 27C128 for the 27-series EPROMS:

Apple2Card.png

There is no need to go higher. The 27C128 chip fits 16K, while the firmware that needs to be written is only 512 bytes: https://github.com/ThorstenBr/Apple2Card/blob/main/eprom/bin/eprom.bin

I currently have around 100 25c512s, and 20 or so w27c512s, and 10 or so 27256s.

So supporting eproms that people may have or use is a good thing. 

It's true that you can just tie that pin high and offset the rom into the bigger chips, but easier if you don't need to.

dabone wrote:

I currently have around 100 25c512s, and 20 or so w27c512s, and 10 or so 27256s.

So supporting eproms that people may have or use is a good thing. 

It's true that you can just tie that pin high and offset the rom into the bigger chips, but easier if you don't need to.

 

You might happen to have lots of those, but larger chips are more expensive and harder to find. So, perhaps going lower instead of higher might be something else to consider, like AT28C16 in DIP24 package.

FYI I've just ordered a batch of boards - they should be available in the UK in the coming weeks. If anyone's interested please dm me. I can also probably prepare full kits (assembled or not).

CVT wrote:

dabone wrote:

I currently have around 100 25c512s, and 20 or so w27c512s, and 10 or so 27256s.

So supporting eproms that people may have or use is a good thing. 

It's true that you can just tie that pin high and offset the rom into the bigger chips, but easier if you don't need to.

 

You might happen to have lo

AT28C64 are super easy to find and reasonably priced.  I've used them in the original DAN ][ design.  Most of the ones I have built I used an AT28C256 ot CAT28C256

I'm doing one more respin of this, and defaulting to pin 27 being tied high for 28cxx compatiblity, but allowing a solder jumper to handle 27 tied low so it can work with 27256s, 27257s, 27512s, and w27c512s.

These will also work with 27 tied high, but then you have to figure out your offset when you burn your image.

That gives the most options and ease of use.

dabone wrote:

I'm doing one more respin of this, and defaulting to pin 27 being tied high for 28cxx compatiblity, but allowing a solder jumper to handle 27 tied low so it can work with 27256s, 27257s, 27512s, and w27c512s.

These will also work with 27 tied high, but then you have to figure out your offset when you burn your image.

That gives the most options and ease of use.

 

&n

Sounds like a plan!

tamsoftware wrote:

FYI I've just ordered a batch of boards - they should be available in the UK in the coming weeks. If anyone's interested please dm me. I can also probably prepare full kits (assembled or not).

Received the boards - all good. Very precise design @profdc9, looks wonderful.

TL;DR: I'm getting random results, each boot returns something new - sometimes I see the menu, sometimes I can navigate, sometimes I see the files, sometimes I don't,.

Sometimes I see the files of slot 1 in slot 2, although it's empty, sometimes in both. It always freezes.

The best I've had so far is the welcome screen of the total_replay disk before freezing. Once in a while I fall back to the monitor after hitting Return.

Jumpers:

• JP2: closed
• JP5: closed
• all others: open

Slot 1: 128MB class 4, FAT 16

• VOL00_TotalRecall_5.2.po
• VOL01_ip65.po

• Slot 2: empty

Ethernet: not yet

I've used @MacFly 's 1.1.1 iBom to get the latest on resistor values: https://htmlpreview.github.io/?https://github.com/ThorstenBr/Apple2Card/blob/main/Apple2Card/bom/ibom.html

(btw, D7 is missing)

IMG_1394.jpeg

• Chips:
  • ATMEGA328P U
  • CP82C55AZ
  • AT28C256
  • 02AF65M
  • 2AA6X9M

I've programmed the ATMega and EEPROM with a T48 as such, using @MacFly 's repo https://github.com/ThorstenBr/Apple2Card.

I'm putting the different atempts for the EEPROM in case it can help others.

$ minipro -p 'ATMEGA328P@DIP28' -c code -w Apple2Arduino.ino.328p.with_bootloader.hex -f ihex -e

Found T48 01.1.03 (0x103)

Warning: T48 support is experimental!

Warning: Firmware is out of date.

  Expected  01.1.31 (0x11f)

  Found     01.1.03 (0x103)

Device code: 48B20792

Serial code: 20EFIUY6TXOA3UVA1KPY5736

Chip ID: 0x1E950F  OK

Found Intel hex file.

Writing Code...  1.81Sec  OK

Reading Code...  0.66Sec  OK

Verification OK

$ minipro -p 'ATMEGA328P@DIP28' -c config -w fuses.cfg

Found T48 01.1.03 (0x103)

Warning: T48 support is experimental!

Warning: Firmware is out of date.

  Expected  01.1.31 (0x11f)

  Found     01.1.03 (0x103)

Device code: 48B20792

Serial code: 20EFIUY6TXOA3UVA1KPY5736

Chip ID: 0x1E950F  OK

Writing fuses... 0.06Sec  OK

Writing lock bits... 0.05Sec  OK

$ minipro -p '28C256' -w ../eprom/bin/eprom.bin

Found T48 01.1.03 (0x103)

Warning: T48 support is experimental!

Warning: Firmware is out of date.

  Expected  01.1.31 (0x11f)

  Found     01.1.03 (0x103)

Device code: 48B20792

Serial code: 20EFIUY6TXOA3UVA1KPY5736

Use -P if you want to write-protect this chip.

Incorrect file size: 512 (needed 32768, use -s/S to ignore)

This chip may be write-protected. Use -u and try again.

$ minipro -p '28C256' -w ../eprom/bin/eprom.bin -s

Found T48 01.1.03 (0x103)

Warning: T48 support is experimental!

Warning: Firmware is out of date.

  Expected  01.1.31 (0x11f)

  Found     01.1.03 (0x103)

Device code: 48B20792

Serial code: 20EFIUY6TXOA3UVA1KPY5736

Use -P if you want to write-protect this chip.

Warning: Incorrect file size: 512 (needed 32768)

Erasing... 0.20Sec OK

Writing Code...  0.09Sec  OK

Reading Code...  0.00Sec  OK

Verification failed at address 0x0000: File=0xE0, Device=0xFF

This chip may be write-protected. Use -u and try again.

$ minipro -p '28C256' -w ../eprom/bin/eprom.bin -s -u

Found T48 01.1.03 (0x103)

Warning: T48 support is experimental!

Warning: Firmware is out of date.

  Expected  01.1.31 (0x11f)

  Found     01.1.03 (0x103)

Device code: 48B20792

Serial code: 20EFIUY6TXOA3UVA1KPY5736

Use -P if you want to write-protect this chip.

Warning: Incorrect file size: 512 (needed 32768)

Erasing... 0.20Sec OK

Protect off...OK

Writing Code...  0.10Sec  OK

Reading Code...  0.00Sec  OK

Verification OK

Apple //e non-enhanced FR/US

• Slot 1: serial card
• Slot 2: A2DVI
• Slot 3: 80-text + 64 MB RAM
• Slot 4: Mouse
• Slot 5: Z80
• Slot 6: Disk II
• Slot 7: Dan II

My soldering looks ok to me:

IMG_1400.jpeg

IMG_1396.jpeg

IMG_1395.jpeg

Any suggestions as to what I can check? Thank you very much!

You may need to change the value of some of the resistors depending on which 82x55 chip you are using.

You may need to change the value of some of the resistors depending on which 82x55 chip you are using.

If you are going to play around with the resistors on the 82c55 chip, you only need to try changing R2 since you only have JP2 installed (but 4.7K has always worked for me.)

Intermittent problems with similar symptoms that I have had were due to Vdd at the uSD cards being too low. Instead of the two IN4148 diodes in series I changed out one of the diodes with a lower Vf schottky diode (about 0.3 instead of 0.7v) The uSD cards were much happier after that. So, check the voltages between pins 4 and 6 on the uSD socket.

I use a different T48 type programmer for the 328p (with Win 10) so can't help much there. I do know the correct fuse settings are vitally important however.

Thank you

I've identified and fixed one issue already - I had soldered the four LEDs the wrong way.

Now it works better as in I often have the menu, the 4 arrow keys are properly detected and usually work, and the boot often starts.

Now it's upon reading the boot drive that it crashes "202C - A=04 X=04 Y=00 P=34 S=EB".

I do get the occasional boot but then freeze while selecting the game. The first initial cold boot is the one that worked the best.

Hmmm I tried putting a second card in slot 2 in case the empty slot could be source of problems.

It would appear the clicking mechanism doesn't work properly. Maybe I over-heated it.

Snif snif ...

Do you see the message "DAN II: PRESS RETURN" every single time you turn on the computer without exception? Because it you don't, the problem is in the two chips to the right or the EPROM. In fact you can remove the two chips on the left and leave just the three on the right and you should still see this message every single time when you restart the machine even as it jumps into the monitor.

This is one divide-and-conquer approach that can help in isolating the problem.

tamsoftware wrote:

Thank you

 

I've identified and fixed one issue already - I had soldered the four LEDs the wrong way.

Now it works better as in I often have the menu, the 4 arrow keys are properly detected and usually work, and the boot often starts.

Now it's upon reading the boot drive that it crashes "202C - A=04 X=04 Y=00 P=34 S=EB".

I do get the occasional

Make sure the polarity of the other diodes and the electrolytic are correct too.  Your pic is a little fuzzy so I would have to blow it up to see.

Do you see the message "DAN II: PRESS RETURN" every single time you turn on the computer without exception? 

yes the "DAN II: PRESS RETURN" is here 100% of the time

Make sure the polarity of the other diodes and the electrolytic are correct too

The 5 diodes match the silkscreen, going to check with the circuit. I believe I've been careful with the electrolytic cap but will double-check as well.

TYVM