IBM PC-DOS 2.10 explorations

All, I've been delving into ancient IBM PC-DOS... 1.0, 2.0 and have landed on 2.10 as the experience I'm going to hang out with for a while. It's stable in QEMU and 86Box and I am able to run MASM 1.0, 2.0 and Pascal 1.0 and 2.0. 86Box is more true to old-school boxes, but qemu runs on my Mac, so I like using Qemu. But, Pascal seems to prefer 86Box, it prints weird characters in qemu w/writeln(), which is annoying, but I'm doing more assembly and BASIC at this point, so Qemu's emulation is sufficient. What I've got working: IBM PC-DOS 2.10 - seems to be working fine in both (installed to fixed disk) IBM Macro Assembler 1.0 and 2.0 - seems to be working fine in both (installed to fixed disk) IBM Pascal 1.0 and 2.0 - hokey in both, tricky about the floppy being present, regardless of debug fix, and doesn't like QEMU. QEdit 2.1 - works great in both (installed to fixed disk) I found some good books on BASIC, Pascal, and Assembly: Albrecht, 1990. Teach Yourself GWBASIC. (covers later BASICA sufficiently) Pardee, 1984. The Waite Group Pascal Primer for the IBM PC. (Great book) Metcalf and Sugiyama, 1985. Compute!'s Beginner's Guide to Machine Language on the IBM PC & PCjr. (Excellent book) Lafore, 1984. The Waite Group Assembly Language Primer for the IBM PC & XT. (Wordy, but good) Pretty much everything I've programmed works fine. Graphics stuff is better in 86Box where I can control the monitor that's attached, but no complaints. Some questions I have related to the exploration: 1. I'm curious if there are other folks out there doing similar stuff? 2. Most of the Assembly examples use DOS interrupt 21 for output. Is this typical of assembly programs of the time, or did folks use other methods? 3. I was able to find a lot of 5150/5160 and other manuals, but I couldn't find an IBM Macro Assembler 2.0 manual (there are plenty of IBM Macro Assembler/2 manuals, but those are for OS/2, not DOS). Does anyone know where I can find one online? 4. In y'all's view, what are the significant differences between IBM PC-DOS 2.10 and it's brother MS-DOS 2.x? 5. I'm thinking of moving on to 3.3 at some point, in your view, what are the advantages? 6. I'm happy to post here, but if y'all know of a more appropriate venue, please suggest it? Thanks, Will -- GPG Fingerprint: 68F4 B3BD 1730 555A 4462 7D45 3EAA 5B6D A982 BAAF