OmniBook 300/425 - Freeing up conventional memory

[Bill (Smithville NJ)]

Dave,

What maximum memory available did you achieve. Which memory manager did you use? And could you make the config.sys and autoexec files available.

I've only been able to achieve 589kb - that's using the msdos 6.22 emm386 and himem. This is for a dos based OB-430 system - no windows loaded.

I tried using QEMM but always ran into problems using the Optimize tool - it would never complete without some warning errors.

Thanks,

Bill
Smithville, NJ

(12-29-2016 04:24 AM)Dave Britten Wrote:  I was always bummed that I could never get OBMAX working on my OB 300, as I thought I'd be stuck with ~420 KB conventional memory forever, but while digging around the OmniBook archives to kill time, I found a document from HP explaining how to disable the DoubleSpace and Flash File System drivers manually and get pretty much the same effect.

http://omnibooks.info/archive/ob300-530/...i01072.htm

This specifically states that it applies to the 425, but I just did it on my 300 running a cloned 1.1 ROM, and it worked perfectly. The key is the OBBOOT.COM utility that controls which of the two drivers will be loaded at startup. They can be toggled independently, so if you want to play it safe, or simply don't want to use extra space on C: copying all the files from the D: ROM partition, you can disable only Double Space, for example (assuming you aren't using it on your C: drive). I'm assuming the selected boot option gets stored somewhere in NVRAM (along with the clock and such), but I'm not 100% certain what the recovery procedure is if you mess up and leave the system non-bootable. Pull the batteries and clear the NVRAM, maybe?

All the execute-in-place stuff - e.g. Windows, Excel, Word - still lives in the memory-mapped portion of ROM and continues working as it did before, it's just the stuff that was on the ROM-based D: filesystem that gets copied. So, you won't be sacrificing any extended memory in Windows.

This kinda makes moot the main reason I just ordered a 2.0 card from a 430, but what the hell, I'm sure I can still come up with plenty of interesting experiments for that.