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About willyvmm

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    jmp $e477
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    Atari Hardware
  1. Hi. Thanks. Again, great job. I just started to do the same, ... but i will only complete the data. I did analyzed only MFM mode, so the following covers only ED and DD. Following FDC279x datasheet, all gaps ($4E bytes) , except one, between IDAM and DAM, can be shortened to be as short as 2 bytes. But, it is not recommended because of PLL synchronization. And the only critical structure is sector layout. All firmwares, are creating identical sector layout (using different software). IndexDatamark is optional, and is not required. SyncMarks, are special bytes, wroten with missing clock bit - its FDC special feature, "commands" F5 and F6. F5 "command" write A1 byte with missing clock bit. (pre DAM sync mark) F5 "command" write C2 byte with missing clock bit. (pre IndexMark sync mark) F7 "command" write 2 bytes CRC, calculated by Hardware In every case sector layout is identical, and is achieved by using different software tricks. MFM sector layout: 12 x $00 3 x PRE DAM sync (F5 "command") 1 x $FE (IDAM) 1 x Track number 1 x Side number 1 x Sector number 1 x Sector Length ($00 = 128, $01 = 256, $02 = 512, $03 = 1024) 2 x CRC (F7 "command") 22 x $4E (GAP - may not be shorter) 12 x $00 3 x PRE DAM sync (F5 "command") 1 x $FB (DAM) xx x DATA (128 or 256 bytes of data, it could be also 512 or 1024) 2 x CRC (F7 "command") 24 x $4E (PostData Gap) (this varries, and is sometime located in leadin area, usually 24 bytes.) All firmwares are using long track LEAD-IN, that is overlapped by last bytes/sector leadout, it is (i guess) to erase any remaining data on track. Thats, not true for xf551 - because of using Index hole. IndexMark, and PreIndexMark Sync are optional, and not required by FDC. I think this should help to explain all. Btw. I could not find any info, that 1050 is not supporting $4E/$4F commands.
  2. Thanks. It makes sense. I took a qiuck peek into 1050 ROM, and can say that info provided in link from 1'st post is absolutelly fabricated... maybe it match its bigger brothers drives (ST) but not 8bit, specially 1050. So i'll have to examine 1050 ROM, and TopDrive (easiest) ROM to find the proper track layout. or Just hook logic analyzer to my 1050 and have some fun
  3. Hello folks. I need to know a logical structure of DD atari floppy track. I found some info here: http://www.ataripreservation.org/websites/freddy.offenga/megazine/ISSUE6-FDTECH.html.. but it seems that is somehow wrong. As SD and ED looks reliable (SD/ED uses ca. 97% of theoretical capacity.), DD track exceeds theoretical limit of bytes on the track. Theoretical capacity is 6510 bytes/track for MFM encoding, alnd half of that for FM encoding. for DD track: 51+18*(112+256)=6675, its 165 bytes more that theoretical capacity ... Is there someone who can explain that? Or Could someone upload Kyroflux image of DD track ? (perfectly would be get it as MFM decoded stream) Or any other idea ? Br. willy.
  4. No. Sorry. Buyt you can send me an email and I will put you on a list.
  5. SOLD OUT. For now. There will be some more after easter, but unfortunatelly the price will be higher. Any question? Just ask me.
  6. Many people are asking me how to buy etc, so i started new thread: http://atariage.com/forums/topic/230666-skunkboard-sillyventure-edition-how-to-buy/
  7. How to buy/pay Plaese send Payment in € (EURO) into my PayPal account : (mynick on AA)@gmail.com (unshure ? contact me!) Include your nick on AA and shipping adresse!!!. Sipping day is Thursday (sometimes also Wednesday). You should get email including tracking number Friday after shipping day. If you don't get tracking number, please contact me immediately. There is also possible to pay via bank transfer, if so please contact me. preorder Price: If there is someone who didn't get preordered SkunkBoard, please contact me. Price for AA users: 75€ + P&P. - payment via PayPal as Gift or add 4% to cover PayPal fees. Ebay price: 90€ + P&P via Ebay (please contact me if you wish to buy via Ebay) P&P: 8€ + 2€ every extra board - insured (1pc - 8€, 2pcs 10€ etc..). This is possible for following countries: .at .be .bg .br .cn .cz .dk .fi .fr .gr .es .nl .in .ie .is .jp .kr .no .nz .pt .sk .si .ch .se .tr .ua .hu .it 12€ all other countries (UK, USA, DE etc ...) - insurance is covering only 1 piece! if you want more - please contact me first. If you are unsure, please contact me!! Willy.
  8. Just follow this guide: http://atariage.com/forums/topic/223026-skunkboard-production-batch-declare-list/?p=3074297 Or send me PM if you have any question. W.
  9. It is working exactly as Rev. 3, because it is Rev. 3 I can see there is something wrong on my website, I guess I missed up permissions. I will check that later today. Thanks for feedback.
  10. Hi guys. Could You please help me to keep an eye over shipping. Please reply for email with tracking number when you receive package. It will help me to keep things in order. Please do not send me PM with confirmation Thanks.
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