hckrnws

I remember UMB. I remember that, as a teenager, I was obsessed with figuring out how to squeeze the most free conventional memory out of MS-DOS 6+ ... or 7+? I was stuck at around 615k, maybe 620ish. It annoyed me greatly, because I knew there was still headroom left.

The thing was, that upper memory wasn't just for TSRs. Anything one can shove there, would happily stay there and run just fine.

My journey towards the most free, conventional memory ended at 637k on my 386 DX-33 with 8megs of RAM and a SoundBlaster card, with everything possible being shoved to high memory. Mouse driver, MSCDEX and even COMMAND.COM.

637k. So proud, much wow!

Good times!

I remember playing at least one game without the mouse, to save those precious KBs…

637k is pretty good! There was an automated command in later DOS versions that would try to optimise memory, but I don't think it got results as good.

MEMMAKER. It was okay, but it was so invasive in modifying your CONFIG.SYS and AUTOEXEC.BAT that I never really trusted it. I preferred hand-optimizing.

> I preferred hand-optimizing.

Same here.

But then, it was my job, it wasn't for gaming or anything. I don't play games much and I had an Acorn Archimedes at home.

I could usually get 620 kB free by hand with no problem, even with a mouse, a CD, and a network stack.

That was enough for 99% of work business apps.

I don't remember the exact number, but I remember that using memmaker and some manual fine-tuning, was on the 620-63X range of conventional RAM.

We did special boot disks to strip out everything but what was needed for the game, but sometimes we still couldn’t make it One day I went to a friends house and he had like way more conventional memory in memtest! What the hell I spent hours and days getting 620kb

He was running Dr -dos

> He was running Dr -dos

Yep, that made it a bit easier.

Still around, you know!

It's the kernel of SvarDOS.

http://svardos.org/

Good times. Our DOS game PaybackTime 2 was only capable of using conventional memory. That was a major reason for the game really not having any proper animations for its player characters.

'MZ' has been confirmed to be the initials of Mark Zbikowski, there's no question about it. It's not "Memory" + "Last".

Given the MZ magic bytes in the EXE format header - see https://en.wikipedia.org/wiki/DOS_MZ_executable, I would have assumed an association with Mark Zbikowski as well.

The ARR is probably Aaron R Reynolds (also associated with the AARD code for detecting non-MSDOS environments), but you can't ask for his opinion since he passed about 20 years ago - https://www.reed.edu/reed-magazine/in-memoriam/obituaries/no....

Also https://en.wikipedia.org/wiki/AARD_code and a Raymond Chen story involving aaronr - https://devblogs.microsoft.com/oldnewthing/20190924-00/?p=10... and a pic of him with the Windows team - https://web.archive.org/web/20191014055254/https://community...

from another os2museum.com article about MS-DOS, https://www.os2museum.com/wp/dos/dos-3-0-3-2/

  The development of DOS 3.0 was led by Mark Zbikowski and *Aaron Reynolds*, both experienced DOS 2.x programmers.

Confirmed by a Hacker News rando. Seems legit.

How about "confirmed by Mark Zbikowski himself in a video interview"? Does that sound better?

https://youtu.be/c6yPoWrdjkU?si=hxvXTE6ZsdvJs5U9&t=1266

(roughly 21:06 into the video)

[dead]