From 36b9d020a2ee241719e7feaea8368406023f15ea Mon Sep 17 00:00:00 2001 From: Thomas Harte Date: Tue, 23 Jan 2024 10:29:33 -0500 Subject: [PATCH] Minor copy fixes; no new substance. --- The-Mockingboard.md | 21 ++++++++++----------- 1 file changed, 10 insertions(+), 11 deletions(-) diff --git a/The-Mockingboard.md b/The-Mockingboard.md index 89ac3ef..01d7271 100644 --- a/The-Mockingboard.md +++ b/The-Mockingboard.md @@ -3,11 +3,11 @@ The Mockingboards are a series of audio expansions for the Apple II, the most co ## AY-3-8910s Each AY is connected to its 6522: -* the 6522 port A connected to the AY's data pins; -* bit 0 of the 6522's port B connected to the AY's BC1; -* bit 1 of the 6522's port B connected to the AY's BCDIR; -* BC2 connected to +5v; and -* bit 2 of the 6522's port B connected to the AY's reset. +* port A is connected to the AY's data pins; +* bit 0 of port B is connected to the AY's BC1; +* bit 1 of port B is connected to the AY's BCDIR; +* BC2 is connected to +5v; and +* bit 2 of port B is connected to the AY's reset. The three channels from each AY are mixed together with equal volume. @@ -15,7 +15,7 @@ The three channels from each AY are mixed together with equal volume. The 6522s are exposed to the processor's bus: * the four register select lines are connected to address lines 0 to 3; and -* the reset and data lines connected as expected. +* the reset and data lines connect as expected. The 6522 for the left channel: * is selected when address line 7 is low; and @@ -27,16 +27,15 @@ The 6522 for the right channel: Both also require the board's IOSEL to be active — they appear only in the ordinary IO area for their board. - ## SSI-263s The SSI-263s are more directly connected to the processor's bus. Both SSIs: -* are connected directly to the processor's data bus; -* have their three register select lines connected to the low three bits of the address bus; +* connect their data bus directly to the processor's data bus; +* connect their three register select lines to the low three bits of the address bus; * use IOSELECT as a prerequisite for chip selection; and -* have their A/R output (i.e. the signal that "may be used as an interrupt request for new phoneme data") connected to the corresponding 6522's CA1. +* connect their A/R output (i.e. the signal that "may be used as an interrupt request for new phoneme data") to the corresponding 6522's CA1. The left channel SSI-263: * is selected when A5 is high. @@ -46,4 +45,4 @@ The right channel SSI-263: ## Clock Rate -All chips are clocked according to the Apple card's phase 1 clock input. So they are clocked at the same rate as the CPU. +All chips are clocked according to the Apple card's phase 1 clock input. So they are clocked at the same rate as the CPU. \ No newline at end of file