| |
Flavioweb
Registered: Nov 2011
Posts: 463 |
Drive code: 1541/81 code conversion.
I have a simple question (for you experts).
This is a drivecode for 1541:
DRV_5BYTELOOP
BVC DRV_5BYTELOOP ; Wait for data from the R/W head
CLV
LDA $1C01
STA (BUFLO),Y
INY
CPY #$05 ; Read 5 GCR bytes
BNE DRV_5BYTELOOP
RTS
How can i translate it to work on a 1581? |
|
| |
Krill
Registered: Apr 2002
Posts: 2980 |
You don't. The 1581 can store an entire track in RAM and is fast enough to discourage from going low-level as on 1541.
Simply use job codes and implement your custom serial protocol only.
(And to answer your question: GCR is not used on the 1581. It accesses disk data using a WD1770 controller, so you'd read and write its registers in drive code. Obviously, this works entirely different than on the 5.25" drives.) |
| |
chatGPZ
Registered: Dec 2001
Posts: 11386 |
its also not really worth optimizing, since all the "slow stuff" happens in hardware :) |
| |
Krill
Registered: Apr 2002
Posts: 2980 |
Oh, i'm pretty sure there is ample room for optimisation, e.g. by interleaving disk controller and serial bus access. But as i said, the drive is so fast it really isn't worth the effort. |
| |
Flavioweb
Registered: Nov 2011
Posts: 463 |
Excluding AAY there are other texts with low level infos on 1581? |
| |
MagerValp
Registered: Dec 2001
Posts: 1078 |
http://cadaver.homeftp.net/rants.htm
Read rants #5, #7, #12, and #13. You can also look at the source for ULoad Model 3 release 1. |
| |
Krill
Registered: Apr 2002
Posts: 2980 |
Firmware including source code: http://www.zimmers.net/anonftp/pub/cbm/firmware/drives/new/1581/
Schematics: http://www.zimmers.net/anonftp/pub/cbm/schematics/drives/new/15..
WD1770 info: http://www.cloud9.co.uk/james/BBCMicro/Documentation/wd1770.html
WD1770/2 datasheet: http://dev-docs.atariforge.org/files/WD1772.pdf
Some general info: http://vice-emu.sourceforge.net/plain/drive_info.txt
A 1581 clone: http://www.students.tut.fi/~leinone3/dcn2692/index.html
And lastly, check the VICE source code: http://sourceforge.net/projects/vice-emu/ |
| |
Krill
Registered: Apr 2002
Posts: 2980 |
Oh, and what do you want to do? Write an IRQ loader with 1581 support? Then yes, see MagerValp's post, and Krill's Loader, repository version 146 has 1581 support, too. |
| |
Flavioweb
Registered: Nov 2011
Posts: 463 |
I have to learn a lot of things...
So thanks for all the infos.
I'm just courius to see if i can imagine how to write an iffl loader that works on 41/71/81 autodetecting the device.
For 41/71 there are no problems.
They comes with 1581.
Should be great if i add a "decrunch on the fly" for level exomized files... |
| |
TNT
Account closed
Registered: Oct 2004
Posts: 189 |
AFAIK the only program using WD177x inside 1581 directly is MMC64 D81 Writer. |
| |
MagerValp
Registered: Dec 2001
Posts: 1078 |
Lasse's rants give you all the information you need to write an IFFL loader that supports 1541/70/71/81/CMD FD/HD - that's how I learned :) |
... 4 posts hidden. Click here to view all posts....
|
| Previous - 1 | 2 - Next |
