A few years ago I fully reversed the 1581 board and made an identical 1:1 reproduction. If the guy with the rotten 1571 board sends it to me I'll reverse it and make the PCB files and gerbers open-source.
Most of the 1571's are dead, either because the CIA chip is dead (and those are available NOS from Mouser), or because the read/write heads have failed open. It would be far better if someone could produce replica 1571 ready/write head assemblies.
@@glenndoiron9317 Given that the board and chips are almost 40 years old it is surprisingly reliable. How many LCD TV's from 2000 are still working now.... I'd say zero. The heads are the main issue. But there is another way to solve that problem. Only a handful of (forgetful) titles were released on double-sided disks so the 1571 isn't required.....
2:08 You only need the Serial Shift Register, Interupt, and TimerA in your 1571 CIA. You can sub in an Amiga 8520 CIA, or any 6526A chips you might have even if they have faulty IO ports.
No. The chip uses DB0-7 and other pins too. I just reversed and re-created the 1571 board and I know for a fact that exactly 20 pins on the 6526 are used. I seriously doubt a partially working 6526 will work. Generally if the chip is bad then it will have other serious issues that affect everything not just a few pins. Anyway 6526 are not that hard to find now.
@@g4z-kb7ct By IO ports I'm talking about the PA[0:7] and PB[0:7] pins. I.E. Pins 2 thru 17. Of course the DB[0:7] pins are required, how else do you program the timers or write to the serial shift registers if you don't connect the data-bus?
@@pits645 You said exactly this... "You only need the Serial Shift Register, Interupt, and TimerA in your 1571 CIA". That is just plain WRONG. If you knew the DB0-7 pins are used you should have said so.... but you didn't lol! In reality you should not have commented at all because now you look dumb and are trying to recover this hole you dug for yourself by adding more info. A bad chip is a bad chip period and should not be used regardless of the fault it has. Next time just keep quiet to avoid the embarressment LOL!
@@pits645 lol if you knew db0-7 was used you should have said so. A bad chip is a bad chip and should not be used regardless. Next time just keep quiet to avoid embarressment lol
Great research. You are right, reverse engineering old Commodore PCBs isn't easy. I went through this with a PCB design guru a few years ago to make a replica SX-64 I/O PCB. If you don't have access to someone with the requisite skills it's a monumental task.
About that LED connector: you could eject the crimp terminals from the crimp housing and rearrange them in the required way. Using ready made Dupont cables is a good thing. You could get some crimp housings and just swap the single pin housings for a fitting (here 7 pin) crimp housing. That might be mechanically more stable. Or you secure the connector with a drop of silicon glue (which can be cut open easily, if required).
Huh, I always thought the boards were the same in a 1571 an a C128. Never did check though. Fwiw, I would just have run an IEC cable between the connectors for a test like this. :)
Hello, a great experiment with the c128. I think it's very interesting. A question: "Does anyone know about the original C65 (!) and a way to deactivate the internal drive? So that I could operate an IEC2SD module? And can you operate a C64 module on a C65 with a C16 adapter? I would be for All suggestions are very grateful. Kind regards, all the best and thanks for the clip. Greetings to all retro technology fans. PS: sorry for my lousy english..😞 your RoboTronic64 from Chemnitz...
if you own a real and working c65 you are one of about maybe 3 people. Meaning no one knows anything or has any experience with it except those 3 people and highly likely 2 of them are not watching this vid or reading your comment ;-) One way could be to change the device number on the internal drive using the usual solder blob jumpers (or software commands) to device 9 and then use the sd2iec as device 8. Another way is use the sd2iec as device 9.
Great work man! I have a 128D without ready cursor in 128 mode: looking this video I now suppose is due to a non working floppy, not a broken cia as I imagined 😞
I'd still suspect the CIA. Does the keyboard work at all, or does it show a cursor in 64 mode? You could always disconnect the IEC cable going to the floppy controller board to disable it (assuming it is not the DCR version)
@@TheRetroChannel if I remember well the keyboard worked in 64 mode ...but I didn't try any floppy with it because I would like to clean the drive before, so now I will try to disconnect the floppy, mine is not a DCR..thank you for now
Sorry, but unless you document all of the changes, down the road, the owner then. will have an UN-repairable KLUDGE. Which will not be cost effective to take the time to repair. Reverse engineering is one thing but jury-rigging is something very different.
A few years ago I fully reversed the 1581 board and made an identical 1:1 reproduction. If the guy with the rotten 1571 board sends it to me I'll reverse it and make the PCB files and gerbers open-source.
He tried to leave a comment but it was automatically removed by RUclips 😒
You can find him in my discord server (link is in the description)
@@TheRetroChannel Yeah he got hold of me. I don't do discord, waste of time ;-)
@@TheRetroChannel Had a chat. You won't believe it, he lives only about 1km from me in the same suburb a couple of streets away lol!
Most of the 1571's are dead, either because the CIA chip is dead (and those are available NOS from Mouser), or because the read/write heads have failed open. It would be far better if someone could produce replica 1571 ready/write head assemblies.
@@glenndoiron9317 Given that the board and chips are almost 40 years old it is surprisingly reliable. How many LCD TV's from 2000 are still working now.... I'd say zero. The heads are the main issue. But there is another way to solve that problem. Only a handful of (forgetful) titles were released on double-sided disks so the 1571 isn't required.....
This is just my type of shenanigans. Always good to know what could get an old C=128 up and running again.
2:08 You only need the Serial Shift Register, Interupt, and TimerA in your 1571 CIA. You can sub in an Amiga 8520 CIA, or any 6526A chips you might have even if they have faulty IO ports.
No. The chip uses DB0-7 and other pins too. I just reversed and re-created the 1571 board and I know for a fact that exactly 20 pins on the 6526 are used. I seriously doubt a partially working 6526 will work. Generally if the chip is bad then it will have other serious issues that affect everything not just a few pins. Anyway 6526 are not that hard to find now.
@@g4z-kb7ct By IO ports I'm talking about the PA[0:7] and PB[0:7] pins. I.E. Pins 2 thru 17. Of course the DB[0:7] pins are required, how else do you program the timers or write to the serial shift registers if you don't connect the data-bus?
@@pits645 You said exactly this... "You only need the Serial Shift Register, Interupt, and TimerA in your 1571 CIA". That is just plain WRONG. If you knew the DB0-7 pins are used you should have said so.... but you didn't lol! In reality you should not have commented at all because now you look dumb and are trying to recover this hole you dug for yourself by adding more info. A bad chip is a bad chip period and should not be used regardless of the fault it has. Next time just keep quiet to avoid the embarressment LOL!
@@pits645 lol if you knew db0-7 was used you should have said so. A bad chip is a bad chip and should not be used regardless. Next time just keep quiet to avoid embarressment lol
@@g4z-kb7ct Nice projection. You're probably the only one to read "IO ports" and assume someone is talking about the data-bus.
Great research. You are right, reverse engineering old Commodore PCBs isn't easy. I went through this with a PCB design guru a few years ago to make a replica SX-64 I/O PCB. If you don't have access to someone with the requisite skills it's a monumental task.
Oh wow, I wouldn't have thought of shoving the header in the connector that way! Thanks !
Great repairing!
Excellent video. Another one saved! U are very smart/intelligent. Great work and troubleshooting. 5 stars
Good video. I've wondered for decades how much that built in drive differs from the 1571. The answer: Not much.
Great job, makes me wonder that no one tried this before...
👍👍👍
Very cool. I suspect that the 6th pin is the shield on the din connector which has little effect if you are not using a shielded cable.
About that LED connector: you could eject the crimp terminals from the crimp housing and rearrange them in the required way. Using ready made Dupont cables is a good thing. You could get some crimp housings and just swap the single pin housings for a fitting (here 7 pin) crimp housing. That might be mechanically more stable. Or you secure the connector with a drop of silicon glue (which can be cut open easily, if required).
Ah yeah true, probably a good idea if it was installing it permanently.
Huh, I always thought the boards were the same in a 1571 an a C128. Never did check though. Fwiw, I would just have run an IEC cable between the connectors for a test like this. :)
lol'd at the unmatched probe connectors!
Very entertaining. What would we do without Dupont connectors?
Sounds like a ROM in the C128D is different.
The ROMs used for the 128D drive and the 1571 are identical.
Made me sad for culling my C128D years ago. 😢
15:42 "gut" 😂 I like You speaking German!
Danke!
Hello, a great experiment with the c128. I think it's very interesting. A question: "Does anyone know about the original C65 (!) and a way to deactivate the internal drive? So that I could operate an IEC2SD module? And can you operate a C64 module on a C65 with a C16 adapter? I would be for All suggestions are very grateful. Kind regards, all the best and thanks for the clip. Greetings to all retro technology fans. PS: sorry for my lousy english..😞 your RoboTronic64 from Chemnitz...
if you own a real and working c65 you are one of about maybe 3 people. Meaning no one knows anything or has any experience with it except those 3 people and highly likely 2 of them are not watching this vid or reading your comment ;-)
One way could be to change the device number on the internal drive using the usual solder blob jumpers (or software commands) to device 9 and then use the sd2iec as device 8. Another way is use the sd2iec as device 9.
🍪
🔩🤖🔩
👍
Great work man! I have a 128D without ready cursor in 128 mode: looking this video I now suppose is due to a non working floppy, not a broken cia as I imagined 😞
I'd still suspect the CIA. Does the keyboard work at all, or does it show a cursor in 64 mode?
You could always disconnect the IEC cable going to the floppy controller board to disable it (assuming it is not the DCR version)
@@TheRetroChannel if I remember well the keyboard worked in 64 mode ...but I didn't try any floppy with it because I would like to clean the drive before, so now I will try to disconnect the floppy, mine is not a DCR..thank you for now
Sorry, but unless you document all of the changes, down the road, the owner then. will have an UN-repairable KLUDGE. Which will not be cost effective to take the time to repair. Reverse engineering is one thing but jury-rigging is something very different.
don't worry I re-made a new c128 style internal 1571 board.