diff --git a/emulators/groovymame.yml b/emulators/groovymame.yml
index 03c67984..1ac68105 100644
--- a/emulators/groovymame.yml
+++ b/emulators/groovymame.yml
@@ -1886,7 +1886,7 @@ files:
     category: bios_zip
     system: imax-macs
     source_ref: "upstream src/mame/seta/macs.cpp:776"
-    note: "no ROM entries in the set"
+    note: "macs2os_l.bin and macs2os_h.bin are both NO_DUMP (src/mame/seta/macs.cpp:532-535). handle_missing_file (src/emu/romload.cpp:529-571) counts a missing NO_DUMP ROM as known bad, not an error, so the machine runs without the set."
 
   - name: macsbios.zip
     required: true
diff --git a/emulators/mame.yml b/emulators/mame.yml
index 5cd99171..7db022bb 100644
--- a/emulators/mame.yml
+++ b/emulators/mame.yml
@@ -2402,9 +2402,10 @@ files:
         sha1: "463962ffe19880135f0d95a7beda79e27448e872"
 
   - name: mac2bios.zip
-    required: true
+    required: false
     category: bios_zip
     source_ref: "upstream src/mame/seta/macs.cpp:776"
+    note: "macs2os_l.bin and macs2os_h.bin are both NO_DUMP (src/mame/seta/macs.cpp:532-535). handle_missing_file (src/emu/romload.cpp:529-571) counts a missing NO_DUMP ROM as known bad, not an error, so the machine runs without the set."
 
   - name: macsbios.zip
     required: true
diff --git a/emulators/mame0258.yml b/emulators/mame0258.yml
index d2061b71..60b4a817 100644
--- a/emulators/mame0258.yml
+++ b/emulators/mame0258.yml
@@ -3,7 +3,7 @@ type: libretro
 core_classification: frozen_snapshot
 source: https://github.com/libretro/mame
 upstream: https://github.com/mamedev/mame/tree/mame0258
-profiled_date: '2026-10-17'
+profiled_date: '2026-10-22'
 source_commit: dc1a96537089d6d4ecd01d9886b21061471c70c0
 upstream_commit: 2e0aa823508663c4a27164be43467d1ef740cdcd
 core_version: '0.258'
@@ -74,6 +74,19 @@ systems:
 - tutor
 - tandy-vis
 - trs80
+- coco
+- scv
+- apple-macintosh-ii
+- electron
+- mc10
+- pc80
+- xegs
+- dragon64
+- acorn-archimedes
+- acorn-bbc-micro
+- elektronika-bk
+- enterprise-64-128
+- vectrex
 - vgmplay
 notes: 'libretro/mame built at the 0.258 release. BIOS root sets read from mamedev/mame at mame0258: the
   sets and their ROMs are that release''s, not the current one''s.'
@@ -107,6 +120,7 @@ files:
 - name: airlbios.zip
   required: false
   category: bios_zip
+  system: sega-naomi
   source_ref: "upstream src/mame/sega/naomi.cpp:10774"
   contents:
   - name: epr-21802.ic27
@@ -1283,6 +1297,7 @@ files:
 - name: f355bios.zip
   required: false
   category: bios_zip
+  system: sega-naomi
   source_ref: "upstream src/mame/sega/naomi.cpp:10773"
   contents:
   - name: epr-22851.ic27
@@ -1308,6 +1323,7 @@ files:
 - name: f355dlx.zip
   required: false
   category: bios_zip
+  system: sega-naomi
   source_ref: "upstream src/mame/sega/naomi.cpp:10772"
   contents:
   - name: epr-21864.ic27
@@ -1470,6 +1486,7 @@ files:
 - name: hod2bios.zip
   required: false
   category: bios_zip
+  system: sega-naomi
   source_ref: "upstream src/mame/sega/naomi.cpp:10771"
   contents:
   - name: epr-21331.ic27
@@ -1638,6 +1655,7 @@ files:
 - name: kviper.zip
   required: true
   category: bios_zip
+  system: konami-viper
   source_ref: "upstream src/mame/konami/viper.cpp:3424"
   contents:
   - name: 941b01.u25
@@ -1682,7 +1700,7 @@ files:
     crc32: f78d14d7
     sha1: f129787e487984edd23bf344f2e9500c85052275
 - name: mac2bios.zip
-  required: true
+  required: false
   category: bios_zip
   source_ref: "upstream src/mame/seta/macs.cpp:796"
   contents: []
@@ -2339,7 +2357,7 @@ files:
     crc32: 9c436cfa
     sha1: 480ea52e74721d1963ced41be5c482b7b913ccd2
 - name: recel.zip
-  required: true
+  required: false
   category: bios_zip
   source_ref: "upstream src/mame/pinball/recel.cpp:505"
   contents: []
diff --git a/emulators/mame0278.yml b/emulators/mame0278.yml
index 92f20dc8..b4677360 100644
--- a/emulators/mame0278.yml
+++ b/emulators/mame0278.yml
@@ -3,7 +3,7 @@ type: libretro
 core_classification: frozen_snapshot
 source: https://github.com/libretro/mame
 upstream: https://github.com/mamedev/mame/tree/mame0278
-profiled_date: '2026-10-17'
+profiled_date: '2026-10-22'
 source_commit: fba50741006fa3e27e1897f589d2048a505b8fd6
 upstream_commit: eb05584a2b8d98d5af5587244c9cb7dcccf660fd
 core_version: '0.278'
@@ -74,6 +74,19 @@ systems:
 - tutor
 - tandy-vis
 - trs80
+- coco
+- scv
+- apple-macintosh-ii
+- electron
+- mc10
+- pc80
+- xegs
+- dragon64
+- acorn-archimedes
+- acorn-bbc-micro
+- elektronika-bk
+- enterprise-64-128
+- vectrex
 - vgmplay
 notes: 'libretro/mame built at the 0.278 release. BIOS root sets read from mamedev/mame at mame0278: the
   sets and their ROMs are that release''s, not the current one''s.'
@@ -107,6 +120,7 @@ files:
 - name: airlbios.zip
   required: false
   category: bios_zip
+  system: sega-naomi
   source_ref: "upstream src/mame/sega/naomi.cpp:10907"
   contents:
   - name: epr-21802.ic27
@@ -1340,6 +1354,7 @@ files:
 - name: f355bios.zip
   required: false
   category: bios_zip
+  system: sega-naomi
   source_ref: "upstream src/mame/sega/naomi.cpp:10906"
   contents:
   - name: epr-22851.ic27
@@ -1365,6 +1380,7 @@ files:
 - name: f355dlx.zip
   required: false
   category: bios_zip
+  system: sega-naomi
   source_ref: "upstream src/mame/sega/naomi.cpp:10905"
   contents:
   - name: epr-21864.ic27
@@ -1536,6 +1552,7 @@ files:
 - name: hod2bios.zip
   required: false
   category: bios_zip
+  system: sega-naomi
   source_ref: "upstream src/mame/sega/naomi.cpp:10904"
   contents:
   - name: epr-21331.ic27
@@ -1704,6 +1721,7 @@ files:
 - name: kviper.zip
   required: true
   category: bios_zip
+  system: konami-viper
   source_ref: "upstream src/mame/konami/viper.cpp:3258"
   contents:
   - name: 941b01.u25
@@ -1748,7 +1766,7 @@ files:
     crc32: f78d14d7
     sha1: f129787e487984edd23bf344f2e9500c85052275
 - name: mac2bios.zip
-  required: true
+  required: false
   category: bios_zip
   source_ref: "upstream src/mame/seta/macs.cpp:791"
   contents: []
diff --git a/emulators/mame2009.yml b/emulators/mame2009.yml
index f78a0c27..1f034cc6 100644
--- a/emulators/mame2009.yml
+++ b/emulators/mame2009.yml
@@ -325,9 +325,10 @@ files:
     source_ref: "upstream src/mame/drivers/twinkle.c:1126"
 
   - name: mac2bios.zip
-    required: true
+    required: false
     category: bios_zip
     source_ref: "upstream src/mame/drivers/macs.c:664"
+    note: "macs2os_l.bin and macs2os_h.bin are both NO_DUMP (src/mame/drivers/macs.c:440-443). handle_missing_file (src/emu/romload.c:429-451) counts a missing NO_DUMP ROM as a warning, not an error, so the machine runs without the set."
 
   - name: macsbios.zip
     required: true
diff --git a/emulators/mame2010.yml b/emulators/mame2010.yml
index 56a08e4f..b4b3de5c 100644
--- a/emulators/mame2010.yml
+++ b/emulators/mame2010.yml
@@ -471,10 +471,11 @@ files:
     source_ref: "source src/mame/drivers/twinkle.c"
 
   - name: mac2bios.zip
-    required: true
+    required: false
     category: bios_zip
     system: imax-macs
     source_ref: "source src/mame/drivers/macs.c:514, 740"
+    note: "macs2os_l.bin and macs2os_h.bin are both NO_DUMP (src/mame/drivers/macs.c:499-502). handle_missing_file (src/emu/romload.c:430-452) counts a missing NO_DUMP ROM as a warning, not an error, so the machine runs without the set."
 
   - name: macsbios.zip
     required: true
diff --git a/emulators/mame2014.yml b/emulators/mame2014.yml
index fec8f2aa..02e3b622 100644
--- a/emulators/mame2014.yml
+++ b/emulators/mame2014.yml
@@ -388,10 +388,11 @@ files:
     source_ref: "upstream src/mame/drivers/suprnova.c:1734"
 
   - name: mac2bios.zip
-    required: true
+    required: false
     category: bios_zip
     system: imax-macs
     source_ref: "upstream src/mame/drivers/macs.c:747"
+    note: "macs2os_l.bin and macs2os_h.bin are both NO_DUMP (src/mame/drivers/macs.c:511-514). handle_missing_file (src/emu/romload.c:431-469) counts a missing NO_DUMP ROM as known bad, not an error, so the machine runs without the set."
 
   - name: macsbios.zip
     required: true
diff --git a/emulators/mame2015.yml b/emulators/mame2015.yml
index 6bc5ca7a..390206d4 100644
--- a/emulators/mame2015.yml
+++ b/emulators/mame2015.yml
@@ -378,10 +378,11 @@ files:
     source_ref: "upstream src/mame/drivers/suprnova.c:1734"
 
   - name: mac2bios.zip
-    required: true
+    required: false
     category: bios_zip
     system: imax-macs
     source_ref: "upstream src/mame/drivers/macs.c:747"
+    note: "macs2os_l.bin and macs2os_h.bin are both NO_DUMP (src/mame/drivers/macs.c:511-514). handle_missing_file (src/emu/romload.c:431-469) counts a missing NO_DUMP ROM as known bad, not an error, so the machine runs without the set."
 
   - name: macsbios.zip
     required: true
diff --git a/emulators/mame2016.yml b/emulators/mame2016.yml
index ae67052e..4dba2460 100644
--- a/emulators/mame2016.yml
+++ b/emulators/mame2016.yml
@@ -350,9 +350,10 @@ files:
     source_ref: "upstream src/mame/drivers/suprnova.cpp:1785"
 
   - name: mac2bios.zip
-    required: true
+    required: false
     category: bios_zip
     source_ref: "upstream src/mame/drivers/macs.cpp:771"
+    note: "macs2os_l.bin and macs2os_h.bin are both NO_DUMP (src/mame/drivers/macs.cpp:523-526). handle_missing_file (src/emu/romload.cpp:359-397) counts a missing NO_DUMP ROM as known bad, not an error, so the machine runs without the set."
 
   - name: macsbios.zip
     required: true
diff --git a/emulators/mamearcade.yml b/emulators/mamearcade.yml
index 23e0017e..76bf17fa 100644
--- a/emulators/mamearcade.yml
+++ b/emulators/mamearcade.yml
@@ -1559,10 +1559,11 @@ files:
         sha1: "463962ffe19880135f0d95a7beda79e27448e872"
 
   - name: mac2bios.zip
-    required: true
+    required: false
     category: bios_zip
     system: imax-macs
     source_ref: "upstream src/mame/seta/macs.cpp:776"
+    note: "macs2os_l.bin and macs2os_h.bin are both NO_DUMP (src/mame/seta/macs.cpp:532-535). handle_missing_file (src/emu/romload.cpp:529-571) counts a missing NO_DUMP ROM as known bad, not an error, so the machine runs without the set."
 
   - name: macsbios.zip
     required: true
diff --git a/emulators/ume2015.yml b/emulators/ume2015.yml
index 8a94a11f..70c94b7f 100644
--- a/emulators/ume2015.yml
+++ b/emulators/ume2015.yml
@@ -382,10 +382,11 @@ files:
     source_ref: "upstream src/mame/drivers/suprnova.c:1734"
 
   - name: mac2bios.zip
-    required: true
+    required: false
     category: bios_zip
     system: imax-macs
     source_ref: "upstream src/mame/drivers/macs.c:747"
+    note: "macs2os_l.bin and macs2os_h.bin are both NO_DUMP (src/mame/drivers/macs.c:511-514). handle_missing_file (src/emu/romload.c:431-469) counts a missing NO_DUMP ROM as known bad, not an error, so the machine runs without the set."
 
   - name: macsbios.zip
     required: true