ZX Breakout - Revision history

Winston at 14:06, 25 March 2019

2019-03-25T14:06:39Z

← Older revision		Revision as of 15:06, 25 March 2019
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	[[Image:Zxbreakout1.jpg\|thumb\|right\|~~510px~~\|ZX Breakout with XC95144XL]]		[[Image:Zxbreakout1.jpg\|thumb\|right\|500px\|ZX Breakout with XC95144XL]]

	This is a CPLD (complex programmable logic device) breakout board for the Spectrum (including 128K and Amstrad models). The original idea behind this board was to provide a breakout board for the ZX Spectrum bus signals, and also level shifting of all the signals to 3.3v with a second set of breakout pins. This was to provide an interface to chips that are not 5v tolerant, such as all current in-production FPGAs.		This is a CPLD (complex programmable logic device) breakout board for the Spectrum (including 128K and Amstrad models). The original idea behind this board was to provide a breakout board for the ZX Spectrum bus signals, and also level shifting of all the signals to 3.3v with a second set of breakout pins. This was to provide an interface to chips that are not 5v tolerant, such as all current in-production FPGAs.
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	== The board ==		== The board ==

	[[Image:Zxbreakout.png\|thumb\|right\|~~510px~~\|ZX Breakout PCB]]		[[Image:Zxbreakout.png\|thumb\|right\|500px\|ZX Breakout PCB]]

	The PCB features the following:		The PCB features the following:

Winston at 14:05, 25 March 2019

2019-03-25T14:05:40Z

← Older revision		Revision as of 15:05, 25 March 2019
Line 1:		Line 1:
	[[Image:Zxbreakout1.jpg\|thumb\|right\|~~500px~~\|ZX Breakout with XC95144XL]]		[[Image:Zxbreakout1.jpg\|thumb\|right\|510px\|ZX Breakout with XC95144XL]]

	This is a CPLD (complex programmable logic device) breakout board for the Spectrum (including 128K and Amstrad models). The original idea behind this board was to provide a breakout board for the ZX Spectrum bus signals, and also level shifting of all the signals to 3.3v with a second set of breakout pins. This was to provide an interface to chips that are not 5v tolerant, such as all current in-production FPGAs.		This is a CPLD (complex programmable logic device) breakout board for the Spectrum (including 128K and Amstrad models). The original idea behind this board was to provide a breakout board for the ZX Spectrum bus signals, and also level shifting of all the signals to 3.3v with a second set of breakout pins. This was to provide an interface to chips that are not 5v tolerant, such as all current in-production FPGAs.
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	== The board ==		== The board ==

	[[Image:Zxbreakout.png\|thumb\|right\|~~500px~~\|ZX Breakout PCB]]		[[Image:Zxbreakout.png\|thumb\|right\|510px\|ZX Breakout PCB]]

	The PCB features the following:		The PCB features the following:

Winston at 21:32, 18 June 2013

2013-06-18T21:32:05Z

← Older revision		Revision as of 22:32, 18 June 2013
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	It is suggested that normal jumper pin headers are used for the jumpers.		It is suggested that normal jumper pin headers are used for the jumpers.

			== Projects for the ZX Breakout ==

			* [[ZX SPI]] - An SPI interface for the Spectrum.

	[[Category:ZX Breakout]]		[[Category:ZX Breakout]]

Winston at 18:14, 19 January 2013

2013-01-19T18:14:08Z

← Older revision		Revision as of 19:14, 19 January 2013
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	Either the Xilinx XC9572XL or the XC95144XL CPLD can be used on this board. To give a rough idea of the logic resources these CPLDs provide, Chris Smith's timing accurate ULA replacement fills an XC95144XL, that's to say this CPLD has a similiar amount of resource to the Spectrum ULA.		Either the Xilinx XC9572XL or the XC95144XL CPLD can be used on this board. To give a rough idea of the logic resources these CPLDs provide, Chris Smith's timing accurate ULA replacement fills an XC95144XL, that's to say this CPLD has a similiar amount of resource to the Spectrum ULA.

			=== Errata ===
			Due to a dumb mistake, the ROMCS circuit is incorrect for the black +2 and +3 machines. If you intend to use the ZX Breakout with one of these, a simple workaround is to just not connect pin 4 of the edge connector (top side, 4th pin from the left) or desolder it if you've already connected it. The board will not work at all with a black +2 or +3 unless you do this, even if you're not planning to use ROMCS. It works fine with all other models as-is.

	== The board ==		== The board ==

	[[Image:Zxbreakout.png\|thumb\|right\|500px\|ZX Breakout PCB]]		[[Image:Zxbreakout.png\|thumb\|right\|500px\|ZX Breakout PCB]]

	'''Errata:''' Due to a dumb mistake, the ROMCS circuit is incorrect for the black +2 and +3 machines. If you intend to use the ZX Breakout with one of these, a simple workaround is to just not connect pin 4 of the edge connector (top side, 4th pin from the left) or desolder it if you've already connected it. The board will not work at all with a black +2 or +3 unless you do this, even if you're not planning to use ROMCS. It works fine with all other models as-is.

	The PCB features the following:		The PCB features the following:

Winston at 18:13, 19 January 2013

2013-01-19T18:13:26Z

← Older revision		Revision as of 19:13, 19 January 2013
Line 10:		Line 10:

	[[Image:Zxbreakout.png\|thumb\|right\|500px\|ZX Breakout PCB]]		[[Image:Zxbreakout.png\|thumb\|right\|500px\|ZX Breakout PCB]]

			'''Errata:''' Due to a dumb mistake, the ROMCS circuit is incorrect for the black +2 and +3 machines. If you intend to use the ZX Breakout with one of these, a simple workaround is to just not connect pin 4 of the edge connector (top side, 4th pin from the left) or desolder it if you've already connected it. The board will not work at all with a black +2 or +3 unless you do this, even if you're not planning to use ROMCS. It works fine with all other models as-is.

	The PCB features the following:		The PCB features the following:

Winston at 13:05, 5 November 2012

2012-11-05T13:05:14Z

← Older revision		Revision as of 14:05, 5 November 2012
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			[[Image:Zxbreakout1.jpg\|thumb\|right\|500px\|ZX Breakout with XC95144XL]]

	This is a CPLD (complex programmable logic device) breakout board for the Spectrum (including 128K and Amstrad models). The original idea behind this board was to provide a breakout board for the ZX Spectrum bus signals, and also level shifting of all the signals to 3.3v with a second set of breakout pins. This was to provide an interface to chips that are not 5v tolerant, such as all current in-production FPGAs.		This is a CPLD (complex programmable logic device) breakout board for the Spectrum (including 128K and Amstrad models). The original idea behind this board was to provide a breakout board for the ZX Spectrum bus signals, and also level shifting of all the signals to 3.3v with a second set of breakout pins. This was to provide an interface to chips that are not 5v tolerant, such as all current in-production FPGAs.

Winston: /* Files */

2012-10-30T22:12:40Z

Files

@@ Line 236: / Line 236: @@
 |}
-== Files ==
+== Xilinx UCF file for pins ==
-I'm still awaiting the first boards. Once they have been tested, PCB layout files and the Xilinx UCF (text constraints) file will be available from links here, and via Subversion.
+Copy and paste this into your UCF text constraints file for the list of pins. Comment out the signals you aren't using with a # in front of that line (ISE will fail at the fitter stage if you have nets defined in your UCF file which don't exist in your design). Signals with "_L" at the end are active low. Note that RESET is active high (it's been inverted). This is generally what you want; the Xilinx library components all have active high reset. The clock is also in phase with the Z80 clock.
 == Components used ==

Winston at 21:07, 16 October 2012

2012-10-16T21:07:15Z

← Older revision		Revision as of 22:07, 16 October 2012
Line 239:		Line 239:

	I'm still awaiting the first boards. Once they have been tested, PCB layout files and the Xilinx UCF (text constraints) file will be available from links here, and via Subversion.		I'm still awaiting the first boards. Once they have been tested, PCB layout files and the Xilinx UCF (text constraints) file will be available from links here, and via Subversion.

			== Components used ==

			{\| class="wikitable" style="text-align: center; color: green;"
			! align="left"\|Refdes
			! Component
			! Package
			! Mfr.
			! Description
			! Notes
			\|-
			\|U1\|\|P565D2T33\|\|D2PAK3\|\|ON Semi\|\|3.3v LDO regulator\|\|
			\|-
			\|U2\|\|74HCT14\|\|SOIC 14\|\|Any\|\|Schmitt trigger inverter, TTL compatible\|\|
			\|-
			\|U3\|\|XC9572XL\|\|TQFP 100\|\|Xilinx\|\|CPLD\|\|Use XC95144XL for more logic resources
			\|-
			\|C1, C2\|\|150uF\|\|Tant B\|\|Any\|\|Capacitor\|\|
			\|-
			\|C3\|\|1uF\|\|1206\|\|Any\|\|Capacitor\|\|
			\|-
			\|C4 to C10\|\|0.1uF\|\|0603\|\|Any\|\|Capacitor\|\|
			\|-
			\|R1\|\|300R\|\|0603\|\|Any\|\|Resistor\|\|
			\|-
			\|Q1\|\|BSS84P\|\|SOT23\|\|Infineon\|\|P channel MOSFET\|\|
			\|-
			\|}

			ZX bus edge connector is an open ended 28 position 0.1 inch pitch connector, with position 5 contacts removed and replaced with a plastic key. This connector usually needs to be hand made by cutting down a larger connector (such as an old ISA bus connector).

			40 pin, 10 pin and 60 pin headers are up to the board's user. It's suggested that SIL sockets are used for the headers since this allows wires to be plugged in and connected to a breadboard etc. However, if a ribbon cable is to be used, a PCB to ribbon connector is recommended.

			It is suggested that normal jumper pin headers are used for the jumpers.

	[[Category:ZX Breakout]]		[[Category:ZX Breakout]]

Winston at 20:46, 16 October 2012

2012-10-16T20:46:18Z

← Older revision		Revision as of 21:46, 16 October 2012
Line 235:		Line 235:
	\|-		\|-
	\|}		\|}

			== Files ==

			I'm still awaiting the first boards. Once they have been tested, PCB layout files and the Xilinx UCF (text constraints) file will be available from links here, and via Subversion.

			[[Category:ZX Breakout]]

Winston at 20:43, 16 October 2012

2012-10-16T20:43:51Z

@@ Line 103: / Line 103: @@
 |-
 |RESET||99||2||3||Buffered; CPLD GSR (active high)
 |-
 |}
@@ Line 196: / Line 198: @@
 |-
 |40||GND||||||
 |-
 |}