Files to burn to Eproms and Jumper functions

[asapreta]

Hi! Where do I can find the contents for the 2716 Eproms? Are they the same as prom5 and prom6?

Also, what are the jumpers for?

Thank you!

[mengstr]

I downloaded my images from https://mirrors.apple2.org.za/Apple%20II%20Documentation%20Project/Interface%20Cards/Disk%20Drive%20Controllers/Apple%20Disk%20II%20Interface%20Card/ROM%20Images/

[btb]

The jumpers just go directly to your eprom's extra address lines, A8, A9 and A10, and you set them high or low to select the region of the eprom where you have placed the desired firmware.

[asapreta]

I downloaded my images from https://mirrors.apple2.org.za/Apple%20II%20Documentation%20Project/Interface%20Cards/Disk%20Drive%20Controllers/Apple%20Disk%20II%20Interface%20Card/ROM%20Images/

Thank you, I thought I need to be something diferent (code or so) to use on regular EEPROMs!

[asapreta]

The jumpers just go directly to your eprom's extra address lines, A8, A9 and A10, and you set them high or low to select the region of the eprom where you have placed the desired firmware.

So, as the code is "small" we can have different codes in the same IC, right? Interesting feature.

[asapreta]

And, I don't know why this project isn't popular. Do people think it won't work?

[btb]

I myself haven't gotten to test it yet (no disk drives), but it should work. @mengstr is your board working now?

[asapreta]

My main doubt was about the code to write in the EEPROMs as they are the same of the PROMs I will send the gerber to create the board and test it.

[btb]

I have built and tested my board, and it doesn't work without some rewiring, which I added to the wiki here: https://github.com/btb/DiskII/wiki/Revision-0-errata

After rewiring, I tested it successfully using the 16 sector firmware that @mengstr linked above.

[asapreta]

I have built and tested my board, and it doesn't work without some rewiring, which I added to the wiki here: https://github.com/btb/DiskII/wiki/Revision-0-errata

After rewiring, I tested it successfully using the 16 sector firmware that @mengstr linked above.

Thanks for all the information and testing. I will try to redesign the board with your fixes.

When you mention unscrambled 16 sector firwmare, we have to change anything from the ones @mengstr linked from Asimov, or just burn to a regular eeprom?

Thank you!

[btb]

No changes needed to the firmware, just make sure you set the jumpers A8 A9 A10 as appropriate (i.e. all LO, assuming you put the .bin files at offset 0 in the EPROMs)

[btb]

The kicad project is now updated with correct wiring as well. I haven't updated the gerbers because I want to make some other changes before I release it as "revision 1"

[asapreta]

No changes needed to the firmware, just make sure you set the jumpers A8 A9 A10 as appropriate (i.e. all LO, assuming you put the .bin files at offset 0 in the EPROMs)

The kicad project is now updated with correct wiring as well. I haven't updated the gerbers because I want to make some other changes before I release it as "revision 1"

Well, this project is evolving a lot. Thank you. I will wait for the updated gerbers then!

[btb]

Revision 1 is now, done, with gerbers here: https://github.com/btb/DiskII/releases/tag/rev1

[asapreta]

Revision 1 is now, done, with gerbers here: https://github.com/btb/DiskII/releases/tag/rev1

Thank you very much. I will make a batch for me. There are some APII needing them here!

[btb]

Thank you very much. I will make a batch for me. There are some APII needing them here!

Great! Let me know how it goes, and check my notes here regarding the parts you need: https://github.com/btb/DiskII/wiki/Materials-Needed

[Daniel102010]

Hello from Ireland, I have ordered few PCB rev.1 but unfortunately didn’t work for me. When I power on my Apple IIe the computer beeps and jumps on the Applesoft Basic. Any idea? Thanks in advance

[btb]

Hello from Ireland, I have ordered few PCB rev.1 but unfortunately didn’t work for me. When I power on my Apple IIe the computer beeps and jumps on the Applesoft Basic. Any idea? Thanks in advance

Sure. So you have a bootable disk in the drive and you're trying to boot from that? Does it boot from basic with "PR#6"? Can you send a photo of your board?

[asapreta]

Hello from Ireland, I have ordered few PCB rev.1 but unfortunately didn’t work for me. When I power on my Apple IIe the computer beeps and jumps on the Applesoft Basic. Any idea? Thanks in advance

Without disks the Apple should hang in the Apple ][ (or Apple //e) logo screen and wait until a disk is present in the drive or a CTRL+RESET is done to go to basic.

Your card seems not being recognized.

[Daniel102010]

Hi, thanks for reply I'm not at home right now but I have some pictures on my phone of my phone with the card. How I have tested: I plugged it in Slot 6 with not disk drive just the card and no other cards present. I turn on the computer and I expect to wait for disk drive but instead just jump into AppleSoft Basic ( same thing as no card plugged at all) At this point I have tried to PR#6 just hanging.

[Daniel102010]

I forgot to mention all the IC are plugged out from tested and fully working Card I can't suspect any of them are bad.

[Daniel102010]

I have found the problem was my fault I setup the jumpers wrong, after connecting the jumpers correctly everything works flawlessly.

[btb]

oh, that's great to know. I'm curious what parts did you end up using for Q2 and Q3? and that pair of resistors on the left, I'm guessing you put two in parallel because you didn't have the right value on hand?

[Daniel102010]

I use 2N3906 and BD140 and yes I don't have 68 ohms resistor and I use two resistors in series 47 ohms and 22 ohms to make a close to 68 ohms

[asapreta]

As our friend had problems with the jumpers, is It possible to creste a table of their positions/selection? Thanks in advance

[Daniel102010]

The corect jumper's setup when you're put the bin files in the lower part of the EPROM are exactly like in the pictures below If you're going to use 2732 EPROM the jumpers will be absolutely the same but it's necessary to take pin 21 out of the socket and connect it to GND conveniently pin 22 it's connected to GND . The modification is done as you can see on the image below for both EPROM's P5 and P6 One more close picture

I hope this helps everyone who wants to DIY this project.

[StormTrooper]

Very interesting project this. Just a note on the DiskII.pdf - it's out of date and does not match with the KiCad schematic.

Trying to troubleshoot a build that is not booting up and the pdf confused me :)

[btb]

I just noticed that myself - fixed now

[btb]

The corect jumper's setup when you're put the bin files in the lower part of the EPROM are exactly like in the pictures below [...]

If you don't want to have to do that bodge on pin 21 of a 2732 EPROM, you can just put the code in the upper half (i.e., from 0800 to 08FF) - I always just do repeating copies of the code to fill up the whole thing anyway.

[msx-solis]

I've Just trying to build this project (thanks for sharing) but also a DISK II emulator. it doesn't work but I don't know if the interface or the drive emulator is wrong. I'm using my AppleIIrev0 with Applesoft and 64k RAM, and I wonder it just go to BASIC but does not try to boot. Is like the rom software was not in place but I tried to look at this (CALL-151 C600.C6FF) and I can show it. I am doing anything wrong? Should my Apple display anything different as soon as the interface is in or only if drive is detected? If I try from BASIC PR#6 the computer hangs and the drive emulator displays "track 0" but again I don't know where the problem is located. The "CHUGGA" BASIC program seems to work as should. Please, give me a hint if you can. Thank you in advance.

[msx-solis]

some pictures to show what I mean: I used W27c512 temporary patch because my 2716 flash chips where too slow and so I need to replace them (150ns) I used BD-140 as MPSU51 replacement (also with a patch). And here you are my DISK-II emulator showing "track 0" on the screen:

[vibr77]

Hello All, I confirmed it is working ! I needed this card because I am building a STM32 disk emulator and my previous controller card seems to be handling the P6 badly. I used as well a BD140G, people need to be careful because there are 2 version of the BD140 (one from STMIcro and one from Onsemi) with different pin configuration. It would be great to have a rev B with the BD140G instead of the very rare MPU51.

Quick question: do I need to solder the pad at the ROM level if I use a jumper on the top left ? (sorry I did not deep dive in the schema)

Thanks again to BTB, great stuff

[btb]

@vibr77 There is no need to do anything with the solder pads under the ROMs, unless you need to use the upper parts of the address space for some reason.

Can you link to a datasheet or more info on the transistors you used? The only info I find for BD140 and BD140G appears to show pin order of ECB or BCE, but the pin order of the MPS-U51 is EBC.

Until someone finds a good reason it should be necessary to use such high-power parts, I recommend just using the simple 2n3906 instead. It has the same pinout and appears to work fine.

[mengstr]

Are the transistors actually necessary at all? As far as I remember they just turn the VCC off for some of the ICs to reduce power consumption when the disk is not in active use. Maybe I'm wrong here - it's not like Woz to add parts that really could have been "Muntzed" away.

[btb]

As far as I know, no. https://github.com/btb/DiskII/wiki/Materials-Needed

[mengstr]

I tend to forget checking out the wikis far too often... 🤣