Mercurial > hg > Members > kono > nitros9-code
view level1/modules/dwwrmess.asm @ 2940:824019cd8744
rb1773: Make 48 TPI floppy disks readonly in 96 TPI drives
Deny the disk destroying write with the narrower heads of the 96 tpi drive
when the user has placed a 48 tpi disk in the 96 tpi drive so he can read
it. Double stepping the drive is then done automatically so as to stay in
mechanical synch with the tracks on a 48 tpi disk. But that, until now, did
not make the disk read-only, this patch does that.
Patch by Gene Heskett and Robert Gault.
| author | Robert Gault <robert.gault@att.net> |
|---|---|
| date | Sat, 25 Jan 2014 23:20:06 +0100 |
| parents | c92a6c65bbd9 |
| children | c505ae3120c4 |
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******************************************************* * * DWWriteMESS * * 4/27/10 AAW - Based on John Linville's example * * Entry: * X = starting address of data to send * Y = number of bytes to send * * Exit: * X = address of last byte sent + 1 * Y = 0 * All others preserved * DWWrite pshs u,d,cc ; preserve registers orcc #$50 ; mask interrupts txByte ldb ,x+ ; get a byte to transmit stb $ffe0 ; write it to the FIFO leay ,-y ; decrement byte counter bne txByte ; loop if more to send puls cc,d,u,pc ; restore registers and return