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(MESS) corvushd: Handle attempt to enter prep mode while in prep mode. (nw)

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This commit is contained in:
Mike Naberezny 2014-07-07 18:41:23 +00:00
parent 1904a39163
commit b69bc3d0b1
2 changed files with 26 additions and 5 deletions
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29
src/emu/machine/corvushd.c
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@ -224,7 +224,7 @@ bool corvus_hdc_t::parse_hdc_command(UINT8 data) {
//
// Prep Commands
//
case PREP_MODE_SELECT: // Apparently I need to be able to do this while in Prep mode
case PREP_MODE_SELECT:
case PREP_RESET_DRIVE:
case PREP_FORMAT_DRIVE:
case PREP_FILL_DRIVE_OMNI:
@ -766,19 +766,38 @@ UINT8 corvus_hdc_t::corvus_read_boot_block(UINT8 block) {
//
// Enter prep mode. In prep mode, only prep mode commands may be executed.
//
// The "prep block" is 512 bytes of Z80 machine code that the host sends to
// the controller. The controller will jump to this code after receiving it,
// A "prep block" is 512 bytes of machine code that the host sends to the
// controller. The controller will jump to this code after receiving it,
// and it is what actually implements prep mode commands. This HLE ignores
// the prep block from the host.
//
// On the Rev B/H drives (which we emulate), a prep block is Z80 machine
// code and only one prep block can be sent. Sending the "put drive into
// prep mode" command (0x11) when already in prep mode is an error. The
// prep block sent by the Corvus program DIAG.COM on the SSE SoftBox
// distribution disk returns error 0x8f (unrecognized command) for this case.
//
// On the OmniDrive and Bank, a prep block is 6801 machine code. These
// controllers allow multiple prep blocks to be sent. The first time the
// "put drive into prep mode" command is sent puts the drive into prep mode.
// The command can then be sent again up to 3 times with more prep blocks.
// (Mass Storage GTI, pages 50-51)
//
// Pass:
// drv: Corvus drive id (1..15) to be prepped
// prep_block: 512 bytes of Z80 machine code, contents ignored
// prep_block: 512 bytes of machine code, contents ignored
//
// Returns:
// Status of command
//
UINT8 corvus_hdc_t::corvus_enter_prep_mode(UINT8 drv, UINT8 *prep_block) {
// on rev b/h drives, sending the "put drive into prep mode"
// command when already in prep mode is an error.
if (m_prep_mode) {
logerror("corvus_enter_prep_mode: Attempt to enter prep mode while in prep mode\n");
return STAT_FATAL_ERR | STAT_ILL_CMD_OP_CODE;
}
// check if drive is valid
if (!corvus_hdc_file(drv)) {
logerror("corvus_enter_prep_mode: Failure returned by corvus_hdc_file(%d)\n", drv);
@ -1060,6 +1079,8 @@ void corvus_hdc_t::corvus_process_command_packet(bool invalid_command_flag) {
} else { // In Prep mode
switch(m_buffer.command.code) {
case PREP_MODE_SELECT:
// when already in prep mode, some drives allow this command to
// be sent again. see corvus_enter_prep_mode() for details.
m_buffer.single_byte_response.status =
corvus_enter_prep_mode(m_buffer.prep_mode_command.drive,
m_buffer.prep_mode_command.prep_block);

2
src/emu/machine/corvushd.h
View File

@ -407,7 +407,7 @@ private:
struct {
UINT8 code; // Command code
UINT8 drive; // Drive number (starts at 1)
UINT8 prep_block[512]; // Z80 machine code payload
UINT8 prep_block[512]; // Machine code payload
} prep_mode_command;
//
// Read Firmware command (Prep Mode 0x32)