II Something
by Clark Hugh Stiles
December 26, 2001 

I plan to install the old assembler into Bernie, very soon, and until I do I'm suspending work on the block editor program. To hold you until then, here's a possibly useful discussion. 

Listing 1: 
]CALL-151
*BE00.BEFF
BE00:4C 10 AC 4C 85 A6 4C 9E BE 4C F0 9A 4C 8C 9F 00-L.,L.&L.>Lp.L...
BE10:F0 FD 00 C1 00 C2 00 C3 00 C4 00 C5 00 C6 00 C7-p}.A.B.C.D.E.F.G
BE20:1B FD 00 C1 00 C2 00 C3 00 C4 00 C5 00 C6 00 C7-.}.A.B.C.D.E.F.G
BE30:07 C3 05 C3 5B B8 5E B8 2F 9A BA 9A 05 01 8D 09-.C.C[8^8/.:.....
BE40:00 00 00 00 00 00 00 00 00 00 00 39 A0 00 00 00-...........99...
BE50:00 00 02 FF 95 04 04 00 00 C3 00 00 00 00 00 00-.........C......
BE60:00 05 01 00 00 00 00 00 00 00 06 03 17 BC 80 02-.............<..
BE70:8D 85 BE 8E 03 BC 29 1F AA BD 6F B8 8D 86 BE AE-..>..<).*=o8..>.
BE80:03 BC 20 00 BF C4 B4 BE B0 01 60 A2 12 DD 5C BA-.< .?D4>0.`".]\:
BE90:F0 05 CA 10 F8 A2 13 BD 6F BA AE 03 BC 38 60 00-p.J.x".=o:..<8`.
BEA0:07 17 BC C3 00 00 00 00 00 00 00 00 01 17 BC 02-.. BEB0:17 BC 80 02 0A 17 BC E3 0F FF FF 0F A5 B7 00 00-.<.... BEC0:00 00 CE C2 27 0C 02 50 18 BC 00 03 17 BC 00 96-..NB'..P.<...<..
BED0:01 03 00 7F 0D 04 01 59 02 27 00 27 00 01 01 00-.......Y.'.'....
BEE0:C3 CF D0 D9 D2 C9 C7 C8 D4 A0 C1 D0 D0 CC C5 AC-COPYRIGHT APPLE,
BEF0:A0 B1 B9 B8 B3 4C B9 A2 4C 05 A3 96 00 00 00 00- 1983L9"L.#.....
*[control-c,return] 
End of Listing. 

That's the Basic.System Global Page. A similar listing on your machine is unlikely to be identical because a bunch of the middle is made up of parameter tables used for MLI calls. This listing came from B2TR, and therefore emulates the GS Monitor, meaning that (depending on the screen width) it's 16 bytes wide, followed by the ASCII equivalent. As noted in an earlier issue, $BEDF-BEF4 is used for a copyright notice and can be reused (provided one checks first), $BEFC.BEFF and $BE9F are zeroes and unused space. $BE67, which is allocated for the V parameter value (if found) is unused -- the V parameter will be parsed and stored, but due to a bug (according to Gary Little, and I've found this info to be completely correct) is stored at $BE68 in error. 

No, I still haven't found the Gary Little book. 

Looking in the Beneath Apple ProDOS Supplement I had my RAM refreshed regarding some more unused space at $BB4B etc -- although that's not exactly where the unused space remains. It depends on the version. Sandy Mossberg (I believe that's who) wrote a STRIP command (used the \ key) which peeled off one layer of ProDOS prefix and was devilishly handy. It was small and fit nicely into this free space. 

I should point out that the free space is a little smaller because in later versions of Basic.System there's an Apple-installed MTR external command which makes it possible to type MTR instead of CALL-151. I'd been away from all this programming for so long I'd forgotten this. It also may move around some, although the $BC7B-BDFF space is used for a variety of things, and I can't say offhand what is and isn't used in every version. According to this book, $BB4B-BC7A is unused, along with $BCA6, $BCFD, and $BDFE.BDFF, which gives you some interesting stuff with which you can CAREFULLY experiment. 

NOTE: all the rest of the space between $BC7B and $BDFF (inclusive) is used for stuff. DON'T EXPERIMENT with it. The names of the open files (up to eight) start at $BCFE. 

Listing 2: 
]CALL-151
*BB40.BDFF
BB40:56 74 E7 A2 04 43 F0 69 07 17 63 E0 51 B1 84 C4-Vtg".Cpi..c`Q1.D
BB50:BF 9A E0 1D 55 4B 06 E1 07 16 71 01 74 F0 56 74-?.`.UK.a..q.tpVt
BB60:EC 0A 05 4E 86 06 81 C2 03 F0 05 BA 02 B1 8E CA-l..N...B.p.:.1.J
BB70:AE 71 B0 24 F0 9A CE 36 B4 2C E2 A8 81 93 F0 06-.q0$p.N64,b(..p.
BB80:0A 9C 10 9E 4B BA BF 36 B4 2C AB 0A E5 D7 7F 56-....K:?64,+.eW.V
BB90:74 E9 AC EA 05 49 F0 3D 05 76 21 C4 E5 67 4E 91-ti,j.Ip=.v!DegN.
BBA0:84 F0 56 74 E0 1D 06 0A F0 56 74 0C 06 0D E0 6C-.pVt`...pVt...`l
BBB0:67 7E A0 54 9F 00 00 00 00 A0 02 B9 18 BC D9 D2-g~ T..... .9. BBC0:BB D0 0C 88 10 F5 20 17 9A 20 9C FC 4C 69 FF 4C-;P...u .. .|Li.L
BBD0:EF AA 4D 54 52 05 00 00 00 04 00 00 00 00 00 08-o*MTR...........
BBE0:00 96 00 96 00 00 00 00 00 00 00 00 00 00 00 00-................
BBF0:00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00-................
BC00:00 00 00 07 20 08 AA B0 00 13 00 00 00 09 24 0A-.... .*0......$.
BC10:01 4F 27 0D 00 FF 00 07 42 43 30 30 2E 42 43 46-.O'.....BC00.BCF
BC20:00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00-................
BC30:00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00-................
BC40:00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00-................
BC50:00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00-................
BC60:00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00-................
BC70:00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00-................
BC80:00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00-................
BC90:00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00-................
BCA0:00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00-................
BCB0:00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00-................
BCC0:00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00-................
BCD0:00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00-................
BCE0:00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00-................
BCF0:00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00-................
BCB0:00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00-................
BCC0:00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00-................
BCD0:00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00-................
BCE0:00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00-................
BCF0:00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00-................
BD00:00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00-................
BD10:00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00-................
BD20:00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00-................
BD30:00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00-................
BD40:00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00-................
BD50:00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00-................
BD60:00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00-................
BD70:00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00-................
BD80:00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00-................
BD90:00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00-................
BDA0:00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00-................
BDB0:00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00-................
BDC0:00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00-................
BDD0:00 00 00 00 00 00 00 00 00 00 00 0 ...[Message truncated] 