Commit Graph

579 Commits

Author SHA1 Message Date
Rodney W. Grimes
624dc0c13b Removed all patch kit headers, sccsid and rcsid strings, put $Id$ in, some
minor cleanup.  Added $Id$ to files that did not have any version info, etc
1993-10-16 17:21:10 +00:00
Rodney W. Grimes
0edf66eca4 Removed all patch kit headers, sccsid and rcsid strings, put $Id$ in, some
minor cleanup.  Added $Id$ to files that did not have any version info, etc
1993-10-16 16:47:35 +00:00
Rodney W. Grimes
b8b4b679c0 Removed all patch kit headers, sccsid and rcsid strings, put $Id$ in, some
minor cleanup.  Added $Id$ to files that did not have any version info, etc
1993-10-16 15:24:44 +00:00
Rodney W. Grimes
34a8ed1be1 Removed all patch kit headers, sccsid and rcsid strings, put $Id$ in, some
minor cleanup.  Added $Id$ to files that did not have any version info, etc
1993-10-16 14:40:57 +00:00
Rodney W. Grimes
47cacd3854 Removed all patch kit headers, sccsid and rcsid strings, put $Id$ in, some
minor cleanup.  Added $Id$ to files that did not have any version info, etc
1993-10-16 14:15:10 +00:00
Rodney W. Grimes
6f78ca6026 Removed all patch kit headers, sccsid and rcsid strings, put $Id$ in, some
minor cleanup.  Added $Id$ to files that did not have any version info, etc
1993-10-16 13:48:52 +00:00
Jordan K. Hubbard
b58f2b4a22 Checked and corrected various bits of grammar, as requested. 1993-10-16 12:41:36 +00:00
Rodney W. Grimes
9157622183 Add:
device ed1 at isa? port 0x300 net irq 5 iomem 0xd8000 vector edintr
1993-10-16 12:28:35 +00:00
Rodney W. Grimes
8b80a85bb0 Disable the aha_set_speed code since it breaks more than it fixes. 1993-10-16 12:27:20 +00:00
Rodney W. Grimes
53d94479dd Fix the document title to match the format of our other docs.
Clean up some stuff so that it reads a little better (some one please
review this for me!)

Adaptec controllers are 154x and 174x series.  Add Buslogic 545S.
1993-10-16 12:22:45 +00:00
Rodney W. Grimes
c4182bc6ea Remove the EPSILON from the release level 1993-10-16 12:06:30 +00:00
Rodney W. Grimes
e16c80bb9e Fix the title up on this, removed the date and format it to match
the RELEASE NOTES.

Adaptec controllers are now 154x and 174x series, no more reference
to specific models.  Revamp the CSI hard disk controller section in
general to be more user readable.

Add the fact that the Mitsumi CDROM controller and drive are now
supported.

Add a note that the Intel 82501 serial chip is NOT supported.

Floppy controller is fd0, not fdc0, same for wd disk controller.
1993-10-16 12:05:51 +00:00
Christoph Robitschko
5e53051768 Allow install floppy to be placed in the B: drive. 1993-10-16 09:12:08 +00:00
Rodney W. Grimes
902e518080 Enable mcd0 (Mistumi CDROM) since we now have load space for it 1993-10-15 12:47:02 +00:00
Rodney W. Grimes
6de3bf82d0 Dont just mask the Megabyte, we need all the bits below too,
and ELIMITNATE THE 28K BOGOUSITY.
1993-10-15 12:33:03 +00:00
David Greenman
836e51b4a3 * Revision 2.8 1993/10/15 10:59:56 davidg
* increase maximum time to wait for transmit DMA to complete to 120us.
 * call ed_reset() if the time limit is reached instead of trying
 * to abort the remote DMA.
 *
 * Revision 2.7  1993/10/15  10:49:10  davidg
 * minor change to way the mbuf pointer temp variable is assigned in
 * ed_start (slightly improves code readability)
 *
 * Revision 2.6  93/10/02  01:12:20  davidg
 * use ETHER_ADDR_LEN in NE probe rather than '6'.
1993-10-15 11:06:41 +00:00
Rodney W. Grimes
960173b9b2 genassym.c:
Remove NKMEMCLUSTERS, it is no longer define or used.

locores.s:
	Fix comment on PTDpde and APTDpde to be pde instead of pte
	Add new equation for calculating location of Sysmap
	Remove Bill's old #ifdef garbage for counting up memory,
	that stuff will never be made to work and was just cluttering
	up the file.

	Add code that places the PTD, page table pages, and kernel
	stack below the 640k ISA hole if there is room for it, otherwise
	put this stuff all at 1MB.  This fixes the 28K bogusity in
	the boot blocks, that can now go away!

	Fix the caclulation of where first is to be dependent on
	NKPDE so that we can skip over the above mentioned areas.
	The 28K thing is now 44K in size due to the increase in
	kernel virtual memory space, but since we no longer have
	to worry about that this is no big deal.

	Use if NNPX > 0 instead of ifdef NPX for floating point code.

machdep.c
	Change the calculation of for the buffer cache to be
	20% of all memory above 2MB and add back the upper limit
	of 2/5's of the VM_KMEM_SIZE so that we do not eat ALL
	of the kernel memory space on large memory machines, note
	that this will not even come into effect unless you have
	more than 32MB.  The current buffer cache limit is 6.7MB
	due to this caclulation.

	It seems that we where erroniously allocating bufpages pages
	for buffer_map.  buffer_map is UNUSED in this implementation
	of the buffer cache, but since the map is referenced in
	several if statements a quick fix was to simply allocate
	1 vm page (but no real memory) to it.

pmap.h
	Remove rcsid, don't want them in the kernel files!

	Removed some cruft inside an #ifdef DEBUGx that caused
	compiler errors if you where compiling this for debug.

	Use the #defines for PD_SHIFT and PG_SHIFT in place of
	constants.

trap.c:
	Remove patch kit header and rcsid, fix $Id$.
	Now include "npx.h" and use NNPX for controlling the
	floating point code.

	Remove a now completly invalid check for a maximum virtual
	address, the virtual address now ends at 0xFFFFFFFF so
	there is no more MAX!!  (Thanks David, I completly missed
	that one!)

vm_machdep.c
	Remove patch kit header and rcsid, fix $Id$.
	Now include "npx.h" and use NNPX for controlling the
	floating point code.

	Replace several 0xFE00000 constants with KERNBASE
1993-10-15 10:34:29 +00:00
Rodney W. Grimes
d42d25c451 param.h:
Mark the fact that PGSHIFT and PDRSHIFT are really the same as
PG_SHIFT and PD_SHIFT, these should be collapsed some day soon.

Document that KERNBASE should really be KPTDPTDI << PDRSHIFT, for
now leave it as the constant 0xFE000000 until I make a seperate
common header file for this stuff (vmaddresses.h?)

Remove NKMEMCLUSTERS define, it was only being used to define
VM_KMEM_SIZE, so why have all the indirection.  Besides who wants
to work in CLBYTE sizes chuncks.


pmap.h:

Fix $Id$ and some other minor format clean ups.

Remove the XXX comment about NKPDE, since it now has the correct value
of 7.

Remove unused LASTPTDI and move the APTD into the very end of memory to
free up 4MB of kernel virtual address space.
Remove unused RSVDPTDI and free up 12MB of kernel virtual address space.


vmparam.h

Fix $Id$.

Increase SHMMAXPGS to 512 (2MB) now that there is room for it to be
bigger.  The XXX comment stays until the kernel moves down in memory
to free up enough space to use the proper default of 4MB.

VM_KMEM_SIZE is now a direct constant stating the size of the kernel
malloc region.  Increased the value from 3MB to 16MB.
1993-10-15 10:07:45 +00:00
Rodney W. Grimes
37378adeb5 Add detection code for what model of AHA154X/Z we are running on,
then use that information to fix the enhancemode features of the
1542C/CF boards by turning them off.

When doing this I found that the Buslogic 545S does NOT properly
mimic the 1542 families AHA_INQUIRE command.  It only returns 1
byte of information, when the adaptec manual clearly states that 4
bytes are to be returned.  I added a printf that explains the error
when we see a 545S for now, I tried to come up with a better solution,
but it involved to much work for now.
1993-10-15 09:43:51 +00:00
Rodney W. Grimes
9f2d973525 Moved wt0 (Wangtek/Archive tape driver) to be with the rest of the
bio (block I/O) devices.

Added mcd0 (Mitsumi CDROM driver) but commented it out since there is not
enough room in this kernel for it.
1993-10-14 21:59:50 +00:00
Rodney W. Grimes
cd632cb9fb >From David Greenman
Bruce Evans had limited the kernel virtual address space to not include the
last 4MB since it was not being used.  Other changes are being made that will
reloate the Alternate Page Directory Table (APDT) into this area so the limit
is being fixed to be the last virtual address. (Infact with this patch you
can now do that relocation)
1993-10-14 18:15:35 +00:00
Rodney W. Grimes
9a91485c70 Remove machdep.c from files.i386 and put machdep.o in the SYSTEM_OBJS
line of Makefile.i386.  Fixes the extra rule that gmake complains about
for machdep.o.  This fix is from Joans 0lsson.

Rework the depends and rules for assym.s and genassym so that we now use
the .depend rule for genassym.o such that if you change any header files
that are included by genassym.c the right things happen.  This is probably
what has caused more bad kernel builds than any other thing in the
Makefile.i386!
1993-10-14 17:09:55 +00:00
Rodney W. Grimes
2fa5acb59a Move the wt0 (archive/wangtek tape driver) so that it is with the
other bio type devices.

Add mcd0 (mitsumi cd rom driver), to bad that GENERICBT is to large,
otherwise I could add this driver to it too.
--- 72,77 ----
1993-10-14 14:05:44 +00:00
Rodney W. Grimes
05a078e0da Makefile to install sample files in /etc/uucp with correct ownership and
permissions
1993-10-14 12:18:29 +00:00
Rodney W. Grimes
242d29de40 Add subdir samples so that the sample scripts can get installed in /etc/uucp.
Add group to Makefile.inc for use in installing sample files
1993-10-14 12:17:58 +00:00
Rodney W. Grimes
2babf84dc2 Add /etc/uucp for uucp configuration files 1993-10-14 12:08:04 +00:00
David Greenman
cc44412791 Disassociate DTR and RTS. They were coupled together and shouldn't have
been. This was necessary to work around problems with some equipment
that don't respond favorably to having these both dropped simultaneously.
1993-10-14 09:13:54 +00:00
Nate Williams
87601b6e8d Updated gzip from version 1.2.2 to 1.2.4 due to popular demand 1993-10-14 00:33:38 +00:00
Rodney W. Grimes
08222b297c Surround printf for uha_init board not responding printf with #ifdef UHADEBUG,
since the main line probe code now tells you it did not find one.
1993-10-14 00:07:04 +00:00
Rodney W. Grimes
b200ffec79 Increase the DELAY that supposedly makes the Bustek 545 work from
1ms to 10ms.  I have my doubts, but oh well.
1993-10-13 16:34:10 +00:00
Rodney W. Grimes
1ff3a1e486 Change uusnap to uustat -a, since we do not have a uusnap installed (some
one did not finish porting uucp/contrib directory)
1993-10-13 16:26:03 +00:00
Rodney W. Grimes
5c644711a9 ALL:
Removed patch kit headers and rcsid strings, add $Id$.

isa.c:

Removed old #ifdef notyet isa_configure code, since it will never be
used, and I have done 90% of what it attempted to.

Add conflict checking code that searchs back through the devtab's looking
for any device that has already been found that may conflict with what
we are about to probe.  Checks are mode for I/O address, memory address,
IRQ, and DRQ.  This should stop the screwing up of any device that has
alread been found by other device probes.
Print out messages when we are not going to probe a device due to
a conflict so the user knows WHY something was not found.  For example:

aha0 not probed due to irq conflict with ahb0 at 11

Now print out a message when a device is not found so the user knows
that it was probed for, but could not be found.  For example:

ed1 not found at 0x320

For devices that have I/O address < 0x100 say that they are on the
motherboard, not on isa!  The 0x100 magic number is per ISA spec.  It
may seem funny that pc0 and sc0 report as being on the motherboard, but
this is due to the fact that the I/O address used is that of the keyboard
controller which IS on the motherboard.  We really need to split the
keyboard probe from the display probe.  It is completly legal to build
a pc with out one or the other, or even with out both!

npx.c:

Return -1 from the probe routine if we are using the Emulator so
that the i/o addresses are not printed, this is the same trick used
for 486's.

Do not print the ``Errors reported via Exception 16'', and
``Errors reported via IRQ 13'' messages any more, since these just lead
to more user confusion that anything.  It still prints the message
``Error reporting broken, using 387 emulator'' so that the person is
aware that there mother board is ill.
1993-10-13 15:59:30 +00:00
Rodney W. Grimes
e5ff3be604 Removed hack that did the R_SHIFT of unsigned numbers, no longer need
to do this as I have changed to using PDTI's as the bases for the vm
system layout.

Eliminate constants SYSPDROFF and SYSPDREND, now use NKPTE to control the size
of the kernel virtual space.

Eliminate constant PDRPDROFF, now use PDTDTPI to control location of PTD,
PTDmap and PTDpde

Eliminate constant APDRPDROFF, now use APTDPTDI to control location of APTD,
APTDmap and APTDpde.

Still need to fix Sysmap location (it is still a constant).

.globl statements are now consistent with respect to <comma><space>, the
<space> being removed from all .globl statements.

Document the fillkpt macro as to what registers control what.

Fix some comments that went past column 80, and clean/line some others up.

Remove constand for _Crtat, now use KERNBASE+constant, this still needs work.

Replace constants for offsets of sigcode parameters with symbolic names
from assym.s

Mark the sigreturn() call with XXX since we use the hardcoded constant
for the system call number, this is bogus and should be a #define or
something some place!

The kernel before and after this change was verified with cmp, not one
byte changed.  These are all cosmetic clean up changes that makes the
code more correct and easier to move the kernels virtual address space
and size.
1993-10-13 07:11:11 +00:00
Rodney W. Grimes
911d8c1f44 Disable rpc services so that inetd no longer hangs when you are not
running portmapper.  These are site specific functionality and should only
be enabled for sites that want them, not by default.

These services REQUIRE portmapper to be running
1993-10-13 06:32:06 +00:00
Rodney W. Grimes
c1c1b7df77 Add Page Table Directory Indexes (NKPDE, KPTDI, PTDPTDI, APTDPTDI) to
be used to replace more constants in locore.
1993-10-12 15:33:18 +00:00
Rodney W. Grimes
a27df7823f KPTDI_LAST renamed to KPTDI 1993-10-12 15:09:37 +00:00
Rodney W. Grimes
988d75b3d6 Eliminate definition of I386_PAGE_SIZE and use NBPG instead
Cleaned up tabs vs spaces after #define to make file consistent.
Removed now unused definitions of I386_PAGE_SIZE and I386_PDR_SIZE

Note That these two where unused and had the wrong values anyway!
Changed I386_KPDES to NKPDE
Changed I386_UPDES to NUPDE

Redid constant assignments of *PTDI's to be sizeable and relative.
1993-10-12 13:58:01 +00:00
Rodney W. Grimes
9aa17d68ce Eliminate definition of I386_PAGE_SIZE and use NBPG instead
Replace 0xFE000000 constants with KERNBASE
Use new definition NKPDE in place of a first-last+1 calculation.
1993-10-12 13:53:25 +00:00
Rodney W. Grimes
da73bf46a5 Fixed PHYSTOKV, addition operator on pointers is the wrong thing to do
here.  This is really a crock, but it works.
1993-10-12 12:08:16 +00:00
Rodney W. Grimes
7a94ec038f Remove erronous definitions of PHYSTOKV, correct one is in param.h now. 1993-10-12 07:15:38 +00:00
Rodney W. Grimes
d529c3d85c Add PHYSTOKV used in scsi drivers with a correct definition based on
KERNBASE.

Change #define<tab> to #define<space> on lines that had it wrong
1993-10-12 07:13:12 +00:00
Rodney W. Grimes
b05fb556cf Use KERNBASE for locating stuff in kernel virtual memory, not hard coded
constants.
1993-10-12 06:59:36 +00:00
Rodney W. Grimes
963a0adea5 i82586 support file for Garrett Wollmans ie driver 1993-10-12 06:53:10 +00:00
Rodney W. Grimes
e191da859f > Gcc2 generates memcpy calls when doing some structure copying in the
> code. As this memcpy generation is done by the compiler it doesn't
> work to have memcpy a macro. Instead I made it a static function that
> calls bcopy.

Okay, I tracked down the d*mn thing that is causing the memcpy to be
emmitted by gcc2.  In the following patch is a fix to eliminate the
one place that was causing gcc to do the memcpy in function ie_readframe
for the ie_recv_frame_desc rfd = *(ie->rframes[num]) structure copy.

I also fixed the code so that the NS (XNS) support would compile with
out error and removed the cruft #define ns_* stuff from the softc
structures (I did this a while back for all the other either drivers)

Removed the $Log$ and all of the old log stuff, that is all kept in
the cvs tree, no need to duplicate it in the file... I'll copy it
into my commit message so that it is all retained, except the
revision numbers are going to get screwed up.

It now compiles cleanly under my LINT kernel...

>  I have not yet tested this on the AT&T fiver cards yet. But, Wollman
> has used it on various other AT&T cards. I'm pretty sure Terry also
> uses this driver.

$Log$ stuff from Garretts original file
 * $Log$
 * Revision 1.32  1993/06/20  15:56:15  wollman
 * Fixed warning message.
 *
 * Revision 1.31  93/06/20  15:52:28  wollman
 * More compilation lint.
 *
 * Revision 1.30  93/06/20  15:48:16  wollman
 * Commented all the rest of the cast-qual warnings.  Might be
 * fixed someday by changing the prototypes of bcopy(), bzero(), etc.
 *
 * Revision 1.29  93/06/20  15:40:13  wollman
 * Started fixing some of the cast-qual warnings (most just commented).
 *
 * Revision 1.28  93/06/12  20:39:14  wollman
 * Changed definition of MK_24 to silence -Wcast-qual.
 *
 * Revision 1.27  93/06/08  17:05:57  wollman
 * Attach routine now returns void.
 *
 * Revision 1.26  93/06/08  16:31:21  wollman
 * Deleted attempt to set watchdog timer, since we don't use it.
 *
 * Revision 1.25  93/04/16  22:15:31  wollman
 * Fixed infinite loop in iestart() which would cause the transmitter
 * to constantly step on the Ethernet, sending the same two packets over
 * and over again.  This crashes the router (really!) and makes other
 * network users very angry.
 *
 * Revision 1.24  93/04/14  23:57:47  wollman
 * Increased transmit buffer size from 1504 to 1512, just in case I don't
 * understand how the MTU is used.
 *
 * Revision 1.23  93/04/14  23:16:19  wollman
 * Fix iestart() so that it only tries to execute a command if one was
 * queued up (oops...).
 *
 * Revision 1.22  93/04/14  23:02:16  wollman
 * Unknown changes.
 *
 * Revision 1.21  93/04/12  18:29:33  wollman
 * Added multiple transmit commands.  Note that they are always queued in
 * pairs (there are only two to begin with), and the I flag is only set
 * on the second one.  This should decrease interrupt activity somewhat.
 *
 * Revision 1.20  93/04/12  15:36:05  wollman
 * Changed setup of config block to take into account difference between
 * StarLAN (10BASE-T) and Ethernet: StarLAN is Manchester, Ethernet is NRZ.
 *
 * Revision 1.19  93/03/23  18:58:44  wollman
 * Raised count of receive buffers from 32 to 48 and included analysis of
 * memory usage in a comment near that definition.
 *
 * Revision 1.18  93/03/18  03:59:53  wollman
 * Last try to get large TCP windows to work...
 *
 * Revision 1.17  93/03/18  03:54:10  wollman
 * Added RNR processing as a part of receive interrupts.  Hopefully this
 * will make everything Just Work now.
 *
 * Revision 1.16  93/03/18  03:23:24  wollman
 * Still having problems with RNR conditions.  Basic problem: say we
 * set TCP window to 16k, which is a semsible value.  Then smart
 * partners will blast 16k to us, of which we can fit 8k minus a bit
 * into our buffers.  (Need to look at that memory map..)  So, we get
 * an RNR interrupt.  The problem is, what do we need to do in this case?
 * The original code doesn't work, but it doesn't hang the system either.
 *
 * Revision 1.15  93/03/18  02:37:00  wollman
 * Disabled watchdog timer.  This gets called from a timeout somewhere,
 * which is running up at softclock.  This is at a higher priority than
 * we are, so we can get interrupted in the process of receiving something
 * by the timer expiration, which is not a nice thing to have happen.
 * Question: how can we keep this functionality, but do it in sync with
 * our interrupts?  (Ugh!)
 *
 * Revision 1.14  93/03/18  02:35:46  wollman
 * Fixed some more problems with receive code---it works!
 *
 * Revision 1.13  93/03/17  20:15:59  wollman
 * Think we fixed the serious (showstopper) bugs in 1.12.
 *
 * Revision 1.12  93/03/15  17:45:39  wollman
 * Changed filtering logic dramatically to avoid the unnecessary copyin
 * for BPF or multicast routing when the packet is not for us.  (We
 * have to run in promiscuous mode in this case.)  We still need to
 * deal with the problem of allocating one mbuf per receive buffer;
 * we should be able to get away with a single mbuf for all reasonable
 * incoming packets, and using an mbuf cluster will help avoid unnecessary
 * copying of data.
 *
 * Revision 1.11  93/01/30  20:23:15  wollman
 * Fiddled with reset code to hopefully make it work better when the
 * watchdog timer expires.  Question: why does it make a difference that
 * we do the same thing through ieioctl() as we were doing before.  The
 * old code, when iereset() was called, the receive unit would completely
 * die.  But, a cycle of ifconfig ie0 down ; ifconfig ie0 up' would bring
 * things back to normal.  So, we try to mimic that now.  Grrr...
 *
 * Revision 1.10  93/01/29  17:26:50  wollman
 * Finally fixed multicast routing/BPF mb_map full problem!!!!
 * It turned out that, when we received a packet not for us, we
 * would just return from ie_readframe(), *WITHOUT* freeing the
 * mbuf that the packet was in.  So, when running in promiscuous
 * mode (i.e., multicast routing or BPF without -p), we would have
 * (on our extremely busy subnet 4) a memory leak of epic proportions.
 *
 * We now hold on to a single mbuf chain allocated in this way,
 * and the next time a packet is read, we free it.  Also, the
 * next time a packet is transmitted, we free it.  This way,
 * we never lose more than 6 mbufs total (and on average more like
 * 3).
 *
 * Revision 1.9  93/01/23  14:22:21  wollman
 * Added some StarLAN Fiber modifications from L. Jonas Olsson.
 *
 * Revision 1.8  93/01/23  14:02:34  wollman
 * Added support for IP multicasting.
 *
 * Revision 1.7  92/11/21  17:51:59  wollman
 * Added StarLAN Fiber version point to my driver.
 *
 * Revision 1.6  92/11/20  18:21:45  wollman
 * Fixed documentation, made out-of-mbuf condition an error.
 *
 * Revision 1.5  92/11/20  18:14:02  wollman
 * Move change of ethertype to host byte order so that it's after
 * bpf_mtap.  Hopefully, this will allow us to listen to incoming
 * IP packets.
 *
 * Revision 1.4  92/11/20  18:11:00  wollman
 * Added code to drop packets when we run out of mbufs rather than
 * panicking.  This should alleviate the problems observed when using tcpdump.
 *
 * Revision 1.3  92/11/14  14:12:40  wollman
 * Added BPF support code.
 *
 * Revision 1.2  92/11/14  13:30:26  wollman
 * Added RCS keywords
 *
1993-10-12 06:52:34 +00:00
David Greenman
357eebce38 incorporated patches from Marc Frajola (marc@escargot.rain.com) to
unset TS_TBLOCK when the RBLEN falls below the low water mark.
1993-10-12 06:32:28 +00:00
Rodney W. Grimes
5e89f9d804 Add ie0 (ATT ether net driver) and mcd0 (Mitsumi cd rom driver) 1993-10-12 06:24:02 +00:00
Rodney W. Grimes
54b7aa6d2b Mitsumi cd rom driver from Holger Viet as fixed up by Gary Clark II.
Still a little rought, but it seems to be working.
1993-10-12 06:08:31 +00:00
Rodney W. Grimes
965373a89e Add support for Holger Viets mitsumi cd rom driver as prepared by Gary
Clark II.
1993-10-11 07:39:13 +00:00
Rodney W. Grimes
460346376e Add support for mitsumi cd rom driver from Holger Viet, as fixed up by
Gary Clark II.
1993-10-11 06:19:40 +00:00
Rodney W. Grimes
0e08d66ab8 >From: Julian Elischer <julian@jules.DIALix.oz.au>
Subject: Re: Error reading from DAT (fwd)
Date: Mon, 11 Oct 1993 03:02:39 -40962758 (WST)

Some tapes won't do anything until you tell them to load.
Other tapes think that being asked to load is a great excuse to
make the next command return a "unit attention" (media changed) error.
Since we need to do the load, throw in a dummy instruction to cop the
error.

specifically for DEC DAT drives.
1993-10-11 04:53:23 +00:00