Hi all, below I copy a message from Jack, the author of UIDEJR, with more details and some corrections to my previous mail here.
I think 3280 bytes is still very small for an universal SATA and IDE/ATAPI CD/DVD/BD driver. And you can even put part of the driver in the HMA if your UMBs are already too full :-) Details about my caches: The maximum lbacache and cdrcache sizes are a bit less than 32 MB or 64 MB, respectively. As lbacache, cdrcache, uide and uidejr all cache data in XMS, you have to load himemx, jemmex, xmgr, himem or similar. For cdrcache, you need 1 kB of DOS RAM for each 2 MB cache plus 5.5 kB for the base module while lbacache needs 2 kB of DOS RAM for each 1 MB cache plus a bit more than 5 kB for the base module. ...cache size is rounded to N*128 kB but less than the default 2 MB will not be very helpful in the lbacache case. For cdrcache, even 128 kB is already a lot more than 1 sector "cached" by SHSUCDX, of course ;-) As Jack already mentions, UIDE makes more use of XMS, so it uses less DOS RAM than my caches but might be a bit slower. On the other hand, UIDE allows you to make very big caches. Regards, Eric > To correct Eric's "sizes" for UIDEJR, they are -- > > * 3280 bytes for the full disk/CD/DVD UIDEJR, or 768 bytes in upper-memory > and 2512 bytes in the HMA when its /H switch is given. > > * 3280 bytes (or 768/2512 bytes with /H) for the CD/DVD only UIDEJR. As > its disk logic is in the middle of the driver, and may not be "cut off" > during loading, the CD/DVD only driver is same size as the full UIDEJR. > > * 1600 bytes for the hard-disk only UIDEJR, or 768 bytes in upper-memory > and 832 bytes in the HMA if its /H switch is given. In this case, the > CD/DVD logic gets "cut off" during loading, making the driver smaller. > Otherwise, all of Eric's comments are correct. UIDEJR is intended to be > a "device-driver only" for hard-disks and CD/DVD drives. It has all of > the full UIDE's features except caching (so it does not address diskettes > at all), and thus it uses less memory than loading UIDE with a /B switch. > UIDEJR usually sets an XMS buffer, which handles I-O when a user's buffer > is "misaligned" for UltraDMA. This gives disks/CDs/DVDs full-speed I-O, > without calling the BIOS for disks or using "PIO mode" for CD/DVD drives. > > UIDEJR has been upgraded "in step" with UIDE and thus has no known "bugs" > nor any "unresolved issues". > > Users who prefer LBAcache for disks and/or CDRcache for CDs/DVDs can load > UIDEJR as their device-driver, and it will perform well. Systems using > protected-mode (JEMM386/JEMMEX) and needing only a smaller cache may find > LBAcache/CDRcache to be slightly faster than UIDE. UIDE must issue more > "XMS moves", which are always a bit slower when protected-mode is active. > > For big caches of about 256-MB or more, UIDE should be used in all cases. > Note that without caching, UIDEJR loses some hard-disk speed and a LOT of > CD/DVD speed. SHSUCDX/SHCDX33E, the "CD Redirector" programs, will only > "cache" the last directory sector plus the last 10 file entries for every > CD/DVD drive. Using CDRcache or the full UIDE, much more is cached, and > the user's system achieves much higher CD/DVD throughput speed. > > Thus, the "preferred" disk/CD/DVD driver choices are -- > > * UIDE by itself, or > > * UIDEJR plus LBAcache and/or CDRcache. > Users should not load both UIDE and LBAcache/CDRcache, as this is "double > caching" and is unneeded. One or the other choice above should be used. > > Also, it is true that all "older" UDMA/XDMA/XCDROM/GCDROM/XGCDROM drivers > are obsolete, cannot detect the full range of devices on the PCI bus, and > the xxCDROM drivers still contain many CD/DVD audio and other "bugs" [all > are "clones" of XCDROM, which had no upgrades after early 2006!]. More > "ancient" drivers such as VIDE-CDD.SYS and OAKCDROM.SYS, with no UltraDMA > nor PCI device-detection logic, are also obsolete and should not be used. > > Users should load only UIDE or UIDEJR as their driver for disks/CDs/DVDs. ------------------------------------------------------------------------------ Create and publish websites with WebMatrix Use the most popular FREE web apps or write code yourself; WebMatrix provides all the features you need to develop and publish your website. http://p.sf.net/sfu/ms-webmatrix-sf _______________________________________________ Freedos-user mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/freedos-user
