DOS ain't dead - Over 4-GB For UIDE/RDISK.

Over 4-GB For UIDE/RDISK. (Announce)

posted by Jack , Fresno, California USA, 15.10.2009, 09:19

> The concept of making memory > 4 GB accessible under DOS is an exciting
> one! I for one welcome all future support and hope you do it soon! I
> have a 16 GB system ...

Regrettably I am retired on low-income, and I have only a 1-GB AMD 3000+
on an old VIA mainboard. I would need a new system with at least 8-GB,
to do such upgrades. In private E-Mails, Japheth noted his top goal is
over 4-GB for his HDPMI, and a "general use" XMS driver over 4-GB is not
yet in big demand. For both of us, over 4-GB "may be a while, yet"!

> 4 GB caches sound great ... How to do this?

UIDE now offers 2-GB caches. At 64-KB per cache block (due to UltraDMA
64-KB "boundaries"), this is 16 blocks per cache megabyte, or 32K blocks
total. For 4-GB, I need 64K total cache blocks and twice as much cache
memory. A few adjustments needed in UIDE's code, but "not a big deal"!

> Re: RDISK and > 4 GB. Will it not be possible to create a FAT32 ramdisk >
> 4 GB? Or are we strictly limited to 2 GB (4 GB with 64-kb cluster) FAT
> volumes?

I still use V6.22 MS-DOS which is FAT-16, so I have no FAT-32 knowledge.
My "guess" is that RDISK will only need to initialize an empty directory
in its RAMdisk memory for FAT-32, as it does now for FAT-16. All RDISK
does after init is to read or write RAMdisk blocks -- the DOS system has
all the "intelligence" about exactly what file system is in use.

> I can understand wanting to maintain compatibility with DOS 6.2, but
> would you consider making a souped-up seperate version of RDISK with >
> 4 GB support for those who use MS- "DOS" 7.1 and DR-DOS, etc?

I prefer not to have 2 drivers. If properly managed, a 2- or 4-GB RAM
disk is still a LOT of data, and it must be copied from elsewhere up to
XMS memory each time a system boots. I can't imagine users wanting to
do this for MORE than a 4-GB RAMdisk on every system boot -- too slow!!

> Another big THANK YOU for all the work you have done Jack, and for your
> wonderful skills!

You are welcome -- DOS must SURVIVE, and so I try to do the best I can,
in all my drivers. No magic, and I am no "Hoodoo Man", just hard work
[43 years, since 1966!], often with nice results like XMGR/UIDE/RDISK!

---
(Account disabled on user's request.)

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Complete thread:

Jwasm 2.0 and 64 bit real mode - swf, 12.10.2009, 22:49 (Announce)
- Jwasm 2.0 and 64 bit real mode - Rugxulo, 13.10.2009, 02:31
- Jwasm 2.0 and 64 bit real mode - Japheth, 13.10.2009, 11:08
  - Jwasm 2.0 and 64 bit real mode - Jack, 13.10.2009, 20:32
  - Jwasm 2.0 and 64 bit real mode - RayeR, 14.10.2009, 00:36
    - Jwasm 2.0 and 64 bit real mode - Japheth, 14.10.2009, 06:08
      - Jwasm 2.0 and 64 bit real mode - RayeR, 14.10.2009, 13:18
        Jwasm 2.0 and 64 bit real mode - ecm, 14.10.2009, 14:14
        Jwasm 2.0 and 64 bit real mode - Rugxulo, 19.10.2009, 10:44
    - Jwasm 2.0 and 64 bit real mode - Jack, 14.10.2009, 10:34
      - Jwasm 2.0 and 64 bit real mode - RayeR, 14.10.2009, 13:41
      - Jwasm 2.0 and 64 bit real mode - swf, 14.10.2009, 16:01
        "Extended" Memory With XMGR. - Jack, 14.10.2009, 19:51
        "Extended" Memory With XMGR. - swf, 15.10.2009, 18:57
        "Extended" Memory With XMGR. - Jack, 15.10.2009, 19:42
      - Jwasm 2.0 and 64 bit real mode - Zyzzle, 15.10.2009, 07:35
        Over 4-GB For UIDE/RDISK. - Jack, 15.10.2009, 09:19