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author Lord-Nightmare <Lord-Nightmare@users.noreply.github.com>2015-05-01 14:04:24 -0400
committer Lord-Nightmare <Lord-Nightmare@users.noreply.github.com>2015-05-01 14:04:24 -0400
commit192f22667ab14d1bfba393a23f0cfacfd3a9fae3 (patch)
tree67bcaabe8d4e5042770f501dbe9203c6acb49201
parent7ca53964f5b725cb2751682c259d2b1c0725b825 (diff)
Update VT100 AVO documentation a bit (n/w)
-rw-r--r--src/mess/drivers/vt100.c6
1 files changed, 4 insertions, 2 deletions
diff --git a/src/mess/drivers/vt100.c b/src/mess/drivers/vt100.c
index 4a03123d791..f127b848683 100644
--- a/src/mess/drivers/vt100.c
+++ b/src/mess/drivers/vt100.c
@@ -562,9 +562,11 @@ MACHINE_CONFIG_END
* The optional AVO character set roms (see below) have: pin 18: /CS2*; pin 20: /CS1; pin 21: CS3 hence they match a normal 2716
*(this is marked on the image as if it was CS2 but the input is tied to gnd meaning it must be /CS2)
- * The AVO itself can hold up to four character set roms on it (see http://www.bitsavers.org/pdf/dec/terminal/vt100/MP00633_VT100_Mar80.pdf
+ * The AVO itself can hold up to four roms on it (see http://www.bitsavers.org/pdf/dec/terminal/vt100/MP00633_VT100_Mar80.pdf
and http://vt100.net/dec/ek-vt1ac-ug-002.pdf )
- at least sixteen of these AVO roms were made, and are used as such:
+ and these roms can depending on jumpers be mapped at 0x8000, OR overlay the main code roms at 0x0000-0x1fff!
+ They may even allow banking between the main code roms and the overlay roms, I haven't traced the schematic.
+ At least sixteen of these AVO roms were made, and are used as such:
(based on EK-VT100-TM-003_VT100_Technical_Manual_Jul82.pdf)
* No roms - normal vt100 system with AVO installed
* 23-069E2 (location e21) - meant for vt100-wa and -wb 'LA120' 'word processing' systems (the mapping of the rom for this system is different than for the ones below)