Commodore 1581 - Burst Transfer Protocol

1011 DISK CHANGE
1100 DISK FORMAT NOT LOGICAL
1101 RESERVED
1110...... SYNTAX ERROR
1111 NO DRIVE PRESENT
BURST TRANSFER PROTOCOL
Before using the following burst transfer routines, you must deter
mine whether or not the peripheral is a fast device. The Fast Serial
(byte mode) protocol makes that determination internally when you
include a query routine (send-cmd-string;). This routine addresses the
peripheral as a listener and thereby determines its speed.
BURST READ
send-cmd-string;
if device-fast then
serial-in;
repeat
read-error;
toggle clock;
repeat
wait-byte;
if status = ok then
toggle-clock;
repeat
wait-byte;
toggle-clock;
store-byte;
until end-of-sector;
until no-more-sectors;
set-clock-high;
eke
CloC
read-1541;
BURST WRITE
send-cmd-string;
if device-fast then
repeat
serial-out;
repeat
send-byte;
until last-byte;
serial-in;
clock-low;
read-err;
clock-high;
until last-sector;
else
write-1581;
(*determine speed*)
(*turn 8520 to input*)
(*repeat for all sectors*)
(*retrieve error byte*)
(*wait for status*)
(Vait for byte*)
(*start double buffer*)
(*get data*)
(* start next*)
(*save data*)
(*release clock line*)
(*send unit read*)
(*determine speed*)
(*repeat for multi-sector*)
(*serial port out*)
(*repeat for sector-size*)
(*sendbyte*)
(*last byte ?*)
(*serial port in*)
(*ready for status*)
(*controller error ?*)
(*restore clock*)
(*until last sector*)
(*unit write*)
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