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svofski / vector06cc

Вектор-06ц в ПЛИС / Vector-06c in FPGA
http://svofski.github.io/vector06cc/
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Implement FDC write mode #22

Closed GoogleCodeExporter closed 9 years ago

GoogleCodeExporter commented 9 years ago 
Floppy drives used to be write-enabled.

Original issue reported on code.google.com by svof...@gmail.com on 18 Jan 2008 at 10:14

GoogleCodeExporter commented 9 years ago

Original comment by svof...@gmail.com on 31 Jan 2008 at 8:31

GoogleCodeExporter commented 9 years ago 
Woo. Hoo.

Even with DMA. Mutisector mode not tested as nothing seems to be using it, just 
like
mutisector read.

Original comment by svof...@gmail.com on 12 Feb 2008 at 1:09

GoogleCodeExporter commented 9 years ago 
Better reopen it.

Rewrote big part of the state machine, command begin-closure mating.. Now both 
BIOSes
seem to be more happy than not, but there's still an occaional miss every now 
and then.

Here's an excerpt from an erroneous write operation:
{{{
430347+`430348+`430349+`43034a+`43034b+`43034c+`43034d+`41034d+
rHST:01034d:00+
4dwHST:00034d4d:00
4d 41 49 ce 05 02 80 35 02-00 00 00 00 00 00 00 MAI....5........
}}}

According to directory entry, the data was supposed to be written to 
HST:01:03:4d,
which is 5 sectors earlier than it was written here (side 0). Who switches 
sides, duh! 

(test case: boot from cullshit.fdd, run
  cc1 aa -az
  cc2 aa
the operaion above is from writing aa.crl)

Original comment by svof...@gmail.com on 16 Feb 2008 at 2:27

GoogleCodeExporter commented 9 years ago 
Some analysis:
if MASTER_COMMAND is printed when entering Write command handler, in faulty 
cases it
retains the value $80, that is ACK. Roughly this means that:

WD issued a WRITE request
WD decided that operation is complete faster than CPU acknowledged BUSY
WD issued CPU_REQUEST_ACK before CPU even started to process ?

Original comment by svof...@gmail.com on 18 Feb 2008 at 11:26

GoogleCodeExporter commented 9 years ago 
CPU_REQUEST_ACK comes from $D0/INTERRUPT command

Original comment by svof...@gmail.com on 19 Feb 2008 at 1:09

GoogleCodeExporter commented 9 years ago 
Mostly done. BDS C chaining is probably related, but it's a new issue.

Original comment by svof...@gmail.com on 22 Feb 2008 at 10:25