China DOS Union

The latest versions of QHIMEM and QHMBOOT are 2.3, which have improved the encoding, and now there are only 64 bytes left in the traditional memory.

http://johnson.tmfc.net/dos/file/qhimem23.zip

***Jack specifically asked me to remind everyone who uses FreeDOS HIMEM or FDXMS that both of these programs have very dangerous design problems. When running high-speed operations, they may cause data loss (for example: Ethernet, UltraDMA reading and writing a large amount of data), because both turn off the CPU interrupts!

[ Last edited by johnsonlam on 2006-5-11 at 17:31 ]

The link above appeared the following error when clicked:
The requested URL /dos/file/qhimem23.zip was not found on this server.

Enter through http://johnson.tmfc.net/dos, but what's inside... You can see for yourself!

It seems to be placed under /freedos/file/. But since QHIMEM can be used under various DOSes (such as MS-DOS) and it's not open source, it might be better to place it under the above /dos/file.

http://johnson.tmfc.net/freedos/file/qhimem23.zip

Should be this one...

1. QDBOOT.SYS can automatically detect if there is a floppy drive. If not (there is none in my machine), it will turn off diskette catcher to save 512 bytes;
2. The /D parameter of QCDMA.SYS can automatically detect if the machine supports it. If not (my acorp 4d845g freezes when using this parameter), it will share a single XMS buffer with QCDROM;
3. The /F parameter of QCDMA.SYS can automatically detect if the machine supports it. If not, it will ignore it.

Originally posted by Wengier at 2006-5-9 01:53 PM:
It seems to be placed under /freedos/file/. However, since QHIMEM can be used under various DOSes (such as MS-DOS) and it is not open source, it might be better to place it under the above /dos/file.

I will correct it later. I just finished some quarrels in the FreeDOS discussion area. I'm really helpless about their "personality rather than the matter".

Originally posted by jmcarl at 2006-5-9 08:11 PM:
1. QDBOOT.SYS can automatically detect whether there is a floppy drive. If there isn't (my machine doesn't have one), then it turns off diskette catcher to save 512 bytes;

Reply is here !!

1) An automatic detection will make the driver larger, and the detection method of each BIOS is different. A more reasonable method is to add a /N (no floppy drive) parameter, and I will try to add it.

2) The "/D" parameter is invalid because that BIOS is too old or of poor quality. QDMA has no way to ask the BIOS whether it can "normally" execute 2 XMS buffers.

3) The "/F" failure is only because of too old chipset, there are inherent errors inside. Those errors make Intel and VIA lose face, so they can't expose their own scars and correct them.

This is why users need to test "/D" and "/F" by themselves first, and then decide to use the parameters suitable for them. QDMA can't be fully automated -- there is simply no information on how to do it!

If "/D" and "/F" are not used, QDMA will be a bit slower, but there is still one XMS buffer to do Overlap and correct I-O alignment (misalign).

If there is no XMS and "/UF" parameter, QCDROM will be a bit slower, but it can still operate most UltraDMA inputs. Using SHCDX33A (not Jason Hood's version) in combination, QCDROM can use UltraDMA to read the CD-ROM directory. The buffer of SHCDX33A can also be correctly aligned.

-----
My English is just average, please see if there are any translation errors.

> A user has a few suggestions:
> 1) Can QDBOOT.SYS automatically check if there is any floppy drive? If not (my machine has none) then close diskette catcher, can save 512 bytes.

An automatic check for diskettes will make QDBOOT much larger. BIOS information on how to do this is not the same for every BIOS. It's better for QDBOOT to have a /N switch, "no floppy drive" logic. I will try to write this.

> 2) Can QDMA.SYS automatically check if the PC supports the parameter "/D" or not? My acorp 4d845g will hang when using "/D". If it's not supported then share XMS buffer with QCDROM.
> 3) Can QDMA.SYS automatically check if "/F" is supported or not? If not just ignore it.

/D fails only with an old or low-quality BIOS. There is no way QDMA can "ask the BIOS" if it can run two XMS buffers properly. /F fails only for old chipset with "errata", errors! Errors make Intel and Via "lose face", so it's hard to discover and fix.

This is why users must test /D and /F, then use them only if they work okay. QDMA can't do such automatic checks -- there's no information on HOW to do them!

If /D and /F are not used, QDMA loses little speed. It still gets one XMS buffer and uses it for overlap, misaligned I-O etc. QCDROM will lose a small bit of speed with no XMS and no /UF switch. But it can still do UltraDMA for most input. Do use SHCDX33A, so QCDROM can do UltraDMA directory reads. SHCDX33A's buffers are properly aligned.
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[ Last edited by johnsonlam on 2006-5-11 at 21:21 ]

After the computer self-tests, it generates a device table (it seems to be called DMI), and the format of this table is fixed. QDBOOT.SYS only needs to check if there is a floppy drive in this table. Since I am using UMBPCI and want to put QDMA/QCDROM in the UMB, I have used the /L parameter, but QCDROM fails to load because QDMA did not use the /D parameter. What should I do?

Originally posted by jmcarl at 2006-5-12 08:35 PM:
After the computer's power-on self-test (POST), it generates a device table (it seems to be called DMI), and the format of this table is fixed.

If you are referring to Windows, not everyone installs Windows first!
What about users who don't have Windows?

He apologized for not being able to add automatic testing. First, there were no materials (he was referring to writing the test subroutine from assembly language), and second, he felt that automatic testing was very likely to cause a system crash.

Because I use umbpci and want to put qdma/qcdrom in umb...

DOS=HIGH,UMB
SHELL=C:\DOS\COMMAND.COM C:\DOS\ /E:512 /P
DEVICE=C:\BIN\QHMBOOT.SYS
DEVICE=C:\BIN\QDBOOT.SYS
DEVICE=C:\BIN\UMBPCI.SYS NOEMS
DEVICEHIGH=C:\BIN\QHIMEM.SYS
DEVICEHIGH=C:\BIN\QDMA.SYS /O /D /F /L
DEVICEHIGH=C:\BIN\QCDROM.SYS /D:CDROM1 /UF /L

Please first try the new version and follow the above example to see if the problem can be solved?
If not, try deleting /D and see.

Original text:
====
Do thank your user for a nice suggestion, and do give him my regrets re:
not being able to do his other auto-checks. No info on HOW to do them,
and I prefer not to try such things and perhaps CRASH the system ANYWAY!
====

[ Last edited by johnsonlam on 2006-5-13 at 17:22 ]

I'm not referring to Windows, but to DOS. There is a DOS software called smbiosd that can display SMBIOS/DMI information in BIOS. The relevant information in its description text may be helpful for the author to compile a program checklist to see if there is a floppy drive.

[ Last edited by jmcarl on 2006-5-15 at 10:56 ]

if not exist xmsxxxx0
fail

Originally posted by darkradx at 2006-5-15 02:46 PM:
if not exist xmsxxxx0
fail

Indeed, using XMSXXXX0 cannot determine whether QHIMEM is loaded, and it is hoped that this will be fixed.

Originally posted by Wengier at 2006-5-15 11:29 PM:

Indeed, using XMSXXXX0 cannot determine whether QHIMEM is loaded, and it is hoped that this will be fixed.

Thank you all for your opinions. I have reported it to the author.

Which is better, QHIMEM and HIMEM from MSDOS7.1, QCDROM and VIDE-CDD?