Sold Commodore 1581 drive mainboard kit replica.
- Thread starter pazuzu72
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JohnnySlick
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Interested in full kit.
JohnnySlick
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Payment sent!
D
Deleted member 14264
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Anyone correct me if I am wrong but the only difference between the 8520 and the HMOS version of the 6526 (with the code 216A) is the time-of-day clock. AFAIK, the 1581 doesn't use the TOD clock so both should do just fine.
The 8520 or HMOS 6526 is required to support the C128's burst mode as both of these chips have a high speed serial port built-in.
Incidentally, a lot of C64c (board 250469) have two 6526 with code 216A but these computers don't even use the high speed port so you could just as well take a pair of old standard 6526 from C64 breadbins, put them in your C64c and use the two 6526 with code 216A on your 1581 board.
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Please note JiffyDOS for the 1571 and 1581 is auto-switching.
But even 6526s don't grow on trees
I did not know the auto switching function. However I'm pretty sure some compilations for 1581 won't work if you don't have the standard rom in the drive. I will check and confirm later.
@pazuzu72
is this your design or a shameless copy of
https://www.forum64.de/index.php?thread/102472-1581replica-gotek1581-1581-pc-drive-adapter/
this thread.
https://www.amibay.com/showthread.php?118992-Commodore-1581-drive-kit-mainboard-with-improvements
the original designer has proof that this is a copy of his.
No more declaration of interest allowed until this is resolved.
is this your design or a shameless copy of
https://www.forum64.de/index.php?thread/102472-1581replica-gotek1581-1581-pc-drive-adapter/
this thread.
https://www.amibay.com/showthread.php?118992-Commodore-1581-drive-kit-mainboard-with-improvements
the original designer has proof that this is a copy of his.
No more declaration of interest allowed until this is resolved.
I admitted without problems to the author that I had cloned the pcb that I bought from him not thinking that he had made any changes. I thought it was an exact copy of the original PCB from 1581, so I couldn't see anything wrong with it. If this violates the amibay rules, please cancel the sale of this product.
Maybe I ask you not to delete it completely just as a reference for those who have already purchased.
Regards.
Maybe I ask you not to delete it completely just as a reference for those who have already purchased.
Regards.
you might want to contact the author ( whom you are competing with on this forum ) of the pcb ( here on Amibay ) and discuss your next move.
thanks
thanks
1581 replica boards received, thank you. International shipping was pleasantly fast with respect to how packages are moving lately.
One note though, the 74LS14 provided was marginal, had to replace to allow correct operation > issue was 74LS14 gate locking up IEC bus when drive not powered up but still connected to IEC bus.
One note though, the 74LS14 provided was marginal, had to replace to allow correct operation > issue was 74LS14 gate locking up IEC bus when drive not powered up but still connected to IEC bus.
After the notification from Wes256 (which I thank) I have done some checks I unfortunately have to confirm that the 74LS14 (in this lot) are faulty.
It has the problem of blocking the IEC bus when the drive is off and another drive is connected.
Just simply replace it with another one but for any problem do not hesitate to contact me for a possible refund of the IC.
It has the problem of blocking the IEC bus when the drive is off and another drive is connected.
Just simply replace it with another one but for any problem do not hesitate to contact me for a possible refund of the IC.
D
Deleted member 14264
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Did you get them from a vendor in China ?
If so, I suggest you see this: https://youtu.be/Knfv-Qp7Q2U
I buy my chips from Digikey or Mouser only.
The marked "74LS14" are C-Mos clones, into the not powered "LS" ics the inputs result electrically insulated,
but the C-Mos input pins have ESD protection diodes that "clamp" the pin to Vcc line, so if Vcc become zero the input pin will force the line to zero, imagine this on serial lines, or on reset lines (the vic20 will be reset)
@pazuzu72
Have you contacted the author of the original design you copied ??
no more sales of this item can go ahead until you have made contact to either stop selling or resolve the issue.
D
Deleted member 14264
Guest
No.
Chinese fake/rebranded chips are CMOS clones. Genuine 74LS chips purchased from authorized distributors use BJTs - NOT CMOS - and accordingly consume more power. They also all have pull-up resistors in all inputs.
If you buy all your logic chips from Amazon or eBay from Chinese vendors then you may think all 74LS chips are CMOS clones. real ones are NOT.
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AFAIK, the 74LS14 used in Commodore 8 bit drives can be replaced with 74HCT14 and both Digikey and Mouser have them in stock.
DO NOT use the 74HC14 because the logic threshold level is 1.5V with 74HCT and it is 2.5V with 74HC when powered at 5Vdc.
See: https://learn.sparkfun.com/tutorials/logic-levels/ttl-logic-levels
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