Reference machines - Revision history

Ped7g: core 2.x values disclaimer

2020-11-18T10:34:10Z

core 2.x values disclaimer

← Older revision		Revision as of 11:34, 18 November 2020
Line 30:		Line 30:
	* The ''top border'' is 49 lines at 50hz or 23 lines at 60Hz on 48k Spectrum; on 128k Spectrum, it is exactly one line shorter at both frame rates. On Pentagon, it's substantially longer, 65 lines. On HDMI, it's 40 lines at 50Hz and 17 at 60Hz.		* The ''top border'' is 49 lines at 50hz or 23 lines at 60Hz on 48k Spectrum; on 128k Spectrum, it is exactly one line shorter at both frame rates. On Pentagon, it's substantially longer, 65 lines. On HDMI, it's 40 lines at 50Hz and 17 at 60Hz.

			(values in table are based on core 2.x timings, the core 3.x slightly modified some 60Hz modes, for example VGA Spectrum +3 has 264 total lines - but I don't have full set of data at this moment to edit the table, so keeping it as is, you can use my [https://github.com/ped7g/ZXSpectrumNextMisc/blob/master/snippets/findVLinesCount.i.asm code-snippet measuring number of lines] to figure out dynamically lines count of user's mode)

	{\| class="wikitable"		{\| class="wikitable"

Hyphz at 15:11, 16 February 2020

2020-02-16T15:11:08Z

← Older revision		Revision as of 16:11, 16 February 2020
Line 1:		Line 1:

			= Reference Machines =

	~~= ZX~~ Spectrum ~~16k =~~		The Spectrum Next is based on five reference machines:

	The cut-down version of the original Spectrum. Has no memory after $7fff, so all memory is contended. Not simulated by the Next since the 48k version is identical but has more memory.		* '''ZX Spectrum 16k''': The cut-down version of the original Spectrum. Has no memory after $7fff, so all memory is contended. Not simulated by the Next since the 48k version is identical but has more memory.

	= ZX Spectrum 48k =		* '''ZX Spectrum 48k''': The original Spectrum. Does not support memory remapping.

	The ~~original~~ Spectrum. ~~Does not support~~ memory remapping~~. 224 T-states per video line. 312 scanlines per frame. 64 preamble lines~~.		* '''ZX Spectrum 128k''': The first enhanced Spectrum made by Sinclair. Supports memory remapping and the shadow screen.

	= ZX Spectrum ~~128k =~~		* '''ZX Spectrum +2A/+3''': The enhanced Spectrums after Amstrad rebranding. This is also the "native" personality of the next.

	~~The first enhanced~~ Spectrum ~~made by Sinclair. Does support~~ memory ~~remapping~~ and ~~thus~~ the ~~shadow screen. 228 T-states per video line. 311 scanlines per frame. 63 preamble lines~~.		* '''Pentagon''': A Russion-made homebrew Spectrum that eliminated contended memory and doubled the clock speed.

	= ~~ZX Spectrum +2A / +3~~ =		= Video Timing =

	The ~~latest enhanced Spectrums after Amstrad rebranding.~~		The video timing of the Next is determined by four factors:

	= Pentagon =		* The video timing of the reference machine selected by the config personality (readable at {{NextRegNo\|$03}})
			* The frame rate, 50hz or 60hz (readable from {{NextRegNo\|$05}}). This can be freely adjusted except that the Pentagon can only run at 50Hz.
			* The configured video output type, VGA or HDMI (readable from {{NextRegNo\|$11}}). If HDMI is selected, the video timing of the selected machine type is completely overridden, so this is considered an alternative machine type below, although not by the Next firmware (which means that if Pentagon is selected, a 60Hz frame rate can be chosen if the output type is HDMI)

	~~Russian-made homebrew Spectrum. Eliminated contended memory and doubled~~ the ~~clock speed. 224 T-states per video~~ line~~. 320 lines. 16 preamble lines.~~		The video output is divided into four phases, starting from the first line of the addressable screen (not the top left corner of the whole screen, which is part of the border):

	~~= ZX~~-~~Uno =~~		* The actual ''display'' is 192 lines in all configurations.
			* The ''bottom border'' is 57 lines at 50Hz or 33 at 60Hz on standard machines; on the Pentagon, it is slightly smaller, 49 lines. On HDMI, it is 40 lines at 50Hz or 20 at 60Hz.
			* The ''vertical blanking period'' is the time taken for the drawing line on CRT monitors to return from the bottom of the screen to the top, which is simulated on modern non-CRT monitors. It is determined entirely by video output standard: 14 lines on VGA, and 40 or 33 lines on HDMI depending on the frame rate.
			* The ''ULA VBLANK Interrupt'' is the point at which the ULA sends an interrupt to the Z80 causing it to wake from HALT instructions and run the frame service routine. On all non-HDMI machines, this happens immediately before the blanking period begins, except for Pentagon where it happens 1 line earlier. On HDMI, because of the longer blanking period, it happens ''during'' the blanking period rather than before. At 50Hz, it happens 25 lines into the blanking period, leaving 15 lines between the interrupt and the actual start of the top border (close to the 14 lines it would be on VGA output). At 60Hz, it happens 24 lines into blanking, leaving only 9 lines.
			* The ''top border'' is 49 lines at 50hz or 23 lines at 60Hz on 48k Spectrum; on 128k Spectrum, it is exactly one line shorter at both frame rates. On Pentagon, it's substantially longer, 65 lines. On HDMI, it's 40 lines at 50Hz and 17 at 60Hz.

	~~Previous FPGA~~-~~based~~ Spectrum ~~enhancement. Added several new video modes and features.~~
			{\| class="wikitable"
			! Machine !! Frame Rate !! Output !! Total output lines !! Display lines !! Bottom border lines !! Blanking period lines !! Top border lines !! Total non-display lines !! ULA interrupt timing
			\|-
			\| Spectrum 48k \|\| 50Hz \|\| VGA \|\| 312 \|\| 192 \|\| 57 \|\| 14 \|\| 49 \|\| 120 \|\| 1 line before blanking
			\|-
			\| Spectrum 128k, +2A, +3 \|\| 50Hz \|\| VGA \|\| 311 \|\| 192 \|\| 57 \|\| 14 \|\| 48 \|\| 119 \|\| 1 line before blanking
			\|-
			\| Pentagon \|\| 50Hz \|\| VGA \|\| 320 \|\| 192 \|\| 49 \|\| 14 \|\| 65 \|\| 128 \|\| 2 lines before blanking
			\|-
			\| Spectrum 48k \|\| 60Hz \|\| VGA \|\| 262 \|\| 192 \|\| 33 \|\| 14 \|\| 23 \|\| 70 \|\| 1 line before blanking
			\|-
			\| Spectrum 128k, +2A, +3 \|\| 60Hz \|\| VGA \|\| 261 \|\| 192 \|\| 33 \|\| 14 \|\| 22 \|\| 69 \|\| 1 line before blanking
			\|-
			\| Any \|\| 50Hz \|\| HDMI \|\| 312 \|\| 192 \|\| 40 \|\| 40 \|\| 40 \|\| 120 \|\| 25 lines into blanking
			\|-
			\| Any \|\| 60Hz \|\| HDMI \|\| 262 \|\| 192 \|\| 20 \|\| 33 \|\| 17 \|\| 70 \|\| 24 lines into blanking
			\|}

Specnext: 3 revisions imported

2019-04-14T10:00:20Z

3 revisions imported

← Older revision		Revision as of 11:00, 14 April 2019
(No difference)

wiki>Omikron at 08:41, 8 November 2017

2017-11-08T08:41:45Z

← Older revision		Revision as of 09:41, 8 November 2017
Line 3:		Line 3:
	= ZX Spectrum 16k =		= ZX Spectrum 16k =

	The cut-down version of the original Spectrum. Has no memory after $~~7999~~, so all memory is contended. Not simulated by the Next since the 48k version is identical but has more memory.		The cut-down version of the original Spectrum. Has no memory after $7fff, so all memory is contended. Not simulated by the Next since the 48k version is identical but has more memory.

	= ZX Spectrum 48k =		= ZX Spectrum 48k =

wiki>Hyphz at 21:22, 18 August 2017

2017-08-18T21:22:08Z

← Older revision		Revision as of 22:22, 18 August 2017
Line 19:		Line 19:
	= Pentagon =		= Pentagon =

	Russian-made homebrew Spectrum. Eliminated contended memory and doubled the clock speed.		Russian-made homebrew Spectrum. Eliminated contended memory and doubled the clock speed. 224 T-states per video line. 320 lines. 16 preamble lines.

	= ZX-Uno =		= ZX-Uno =

	Previous FPGA-based Spectrum enhancement. Added several new video modes and features.		Previous FPGA-based Spectrum enhancement. Added several new video modes and features.

wiki>Hyphz: Created page with " = ZX Spectrum 16k = The cut-down version of the original Spectrum. Has no memory after $7999, so all memory is contended. Not simulated by the Next since the 48k version is..."

2017-08-18T16:12:32Z

Created page with " = ZX Spectrum 16k = The cut-down version of the original Spectrum. Has no memory after $7999, so all memory is contended. Not simulated by the Next since the 48k version is..."

New page

= ZX Spectrum 16k =

The cut-down version of the original Spectrum. Has no memory after $7999, so all memory is contended. Not simulated by the Next since the 48k version is identical but has more memory.

= ZX Spectrum 48k =

The original Spectrum. Does not support memory remapping. 224 T-states per video line. 312 scanlines per frame. 64 preamble lines.

= ZX Spectrum 128k =

The first enhanced Spectrum made by Sinclair. Does support memory remapping and thus the shadow screen. 228 T-states per video line. 311 scanlines per frame. 63 preamble lines.

= ZX Spectrum +2A / +3 =

The latest enhanced Spectrums after Amstrad rebranding.

= Pentagon =

Russian-made homebrew Spectrum. Eliminated contended memory and doubled the clock speed.

= ZX-Uno =

Previous FPGA-based Spectrum enhancement. Added several new video modes and features.