AMRAM2 - Revision history

Arnoldemu: /* Technical */

2016-12-28T13:12:02Z

‎Technical

2016-12-26T15:39:51Z

‎Technical

2016-12-26T15:12:44Z

‎Technical

2012-12-21T10:26:18Z

2012-12-21T10:25:48Z

2012-12-21T10:24:26Z

2012-03-14T06:46:51Z

2012-03-14T06:46:08Z

2011-08-27T13:50:00Z

2011-06-29T14:43:34Z

← Older revision		Revision as of 13:12, 28 December 2016
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	When reading as a ROM it is not necessary to use port FBF0. The normal ROM select procedure applies.		When reading as a ROM it is not necessary to use port FBF0. The normal ROM select procedure applies.
		+
		+	On reset or power cycle Amram2 write protect via FBF0 is disabled.

	== Pictures ==		== Pictures ==

← Older revision		Revision as of 15:39, 26 December 2016
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	When writing Amram2 must be enabled using FBF0 BEFORE selecting the page with DFxx.		When writing Amram2 must be enabled using FBF0 BEFORE selecting the page with DFxx.
		+
		+	For fully reliable operation, use fbf0=0 then re-select rom with DFxx to ensure writing is fully disabled.

	When reading as a ROM it is not necessary to use port FBF0. The normal ROM select procedure applies.		When reading as a ROM it is not necessary to use port FBF0. The normal ROM select procedure applies.

@@ Line 36: / Line 36: @@
   A15-A0: xxxx10111111xxxx
-When writing data only bit 0 of the data is significant all other bits are ignored.
+When writing data only bit 0 of the data is significant all other bits are ignored. This has been confirmed with testing.
-If bit 0 is 1, then AMRAM is activated and writing to it's RAM is possible. If bit is 0, then AMRAM is not active.
+If bit 0 is 1, then AMRAM is activated and writing to it's RAM is possible. If bit is 0, then AMRAM is not active and writing has no effect.
-The ROM select is decoded in the normal way: Bit 13=0, all other bits are ignored.
+The ROM select is decoded in the normal way: Bit 13=0 of the address and all other bits of the address are ignored.
-In addition the ROM select IDs are decoded fully, there is no repeat accross the 256 ROM range. The ROMs only exist in their designated slots (i.e. 1 only exists at position 1 and no others).
+In addition the ROM select IDs are decoded fully, there is no repeat across the 256 ROM range. The ROMs only exist in their designated slots (i.e. 1 only exists at position 1 and no others).
 == Pictures ==

@@ Line 27: / Line 27: @@
   Thickness:  6.7 mm.
-With modification a CR2032 battery can be used.
+With modification (old battery removed, a socket and some wires added) a CR2032 battery can be used.
 == Technical ==

@@ Line 26: / Line 26: @@
   Width: 25.4 mm.
   Thickness:  6.7 mm.
 == Technical ==

← Older revision		Revision as of 06:46, 14 March 2012
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	[[media:amram2.zip\|AMRAM 2 ROM]]		[[media:amram2.zip\|AMRAM 2 ROM]]

−	[[Category:~~Peripherals~~]][[Category:~~Music and sound~~]]	+	[[Category:Expansion ROM]][[Category:Peripherals]]

@@ Line 44: / Line 44: @@
 </gallery>
-==Files==
+==Download==
 Amram 2 user manual:
 [[File:Amram2.pdf]]
 [[Category:Peripherals]]

@@ Line 5: / Line 5: @@
 On the bottom is passthrough for other expansion connectors and a 3V square lithium battery. (The exact replacement battery (40LF220 SAFT Memoguard 3.0V Lithium Encapsulated Cell) is expensive @ £19.49 each. It *is* possible to fit a PC CMOS compatible lithium battery (CR2032) and holder, but it's not as neat and there is not a lot of space between the two pcb boards of the Amram)
-On the top, 32K RAM (contents are held by lithium battery so can survive a reset or power off), which can be programmed like ROM and occupies two ROM positions (1 and 2) and also sockets for expansion ROMs up to ROM 7.
+On the top, 32K RAM (contents are held by lithium battery so can survive a reset or power off), which can be programmed like ROM and occupies two ROM positions (1 and 2) and also sockets for expansion ROMs 3,4,5 and 6.
 There is a bank of DIP switches to enable/disable ROM slots, a switch to enable/disable writes to 32K RAM (left side of top pcb), a LED to indicate RAM is ready to write and a switch to reset computer (right side of top pcb).