29 Commits

Author	SHA1	Message	Date
Thomas Harte	60e8273de2	Tweaks video timing, again.	2021-04-06 21:04:54 -04:00
Thomas Harte	1da51bee6c	14368 and six seem to be the proper numbers, per my comprehension of Patrick Rak.	2021-04-04 19:52:19 -04:00
Thomas Harte	044ac949ba	Rearrange fields.	2021-04-01 12:44:00 -04:00
Thomas Harte	87317f5673	Improve documentation, pin down read/write times.	2021-04-01 12:38:58 -04:00
Thomas Harte	4f80523828	Tweaks contended timing.	2021-03-31 22:51:20 -04:00
Thomas Harte	465ecc4a78	Attempts to implement proper floating bus behaviour. ... As per http://sky.relative-path.com/zx/floating_bus.html	2021-03-24 20:23:33 -04:00
Thomas Harte	0ac11fc39e	Add floating bus.	2021-03-23 17:09:42 -04:00
Thomas Harte	d0776b58cf	Tweaks timing empirically.	2021-03-22 23:20:49 -04:00
Thomas Harte	60e77785e8	Makes an attempt to provide the necessary hook for floating bus behaviour.	2021-03-22 22:34:28 -04:00
Thomas Harte	19cd6a55d3	Rejigs the way video is counted to orient it around fetch times.	2021-03-22 22:18:38 -04:00
Thomas Harte	4a12d7086d	Makes another guess at total colour phase.	2021-03-22 17:24:38 -04:00
Thomas Harte	a6b75b8637	Attempts improvements to video fetch timing. Alas, a lot of guess work here.	2021-03-22 15:59:03 -04:00
Thomas Harte	bdb3bce8d6	Corrects semantics on contended-timing calculation.	2021-03-22 15:48:51 -04:00
Thomas Harte	6482303063	Reduces code duplication slightly.	2021-03-21 20:34:58 -04:00
Thomas Harte	064667c0c3	Corrects asymmetrical flash, ensures consistent burst phase.	2021-03-21 20:22:27 -04:00
Thomas Harte	1b0f45649e	Improves contended timing. ... Still not quite on the money, but this was an overt bug.	2021-03-21 00:00:18 -04:00
Thomas Harte	42bfabbe8c	The implication seems to be of a fixed phase swing. ... I'm enquiring further.	2021-03-20 23:46:13 -04:00
Thomas Harte	26911a16e8	Lengthens sync, better to conform to PAL; experiments with fixed-phase colour burst. ... I need to get hold of real documentation here.	2021-03-20 10:38:21 -04:00
Thomas Harte	7d59ff6d8f	Builds in a colour burst, producing colour composite.	2021-03-19 22:25:37 -04:00
Thomas Harte	93b9ea67e6	Takes a run at contended timings.	2021-03-19 08:49:56 -04:00
Thomas Harte	44240773ef	Corrects address generation, ink/paper selection. ... Seemingly to give a correct +2a boot. Time to add a keyboard and find out, I guess.	2021-03-18 23:30:48 -04:00
Thomas Harte	020a04006e	Adds flashing, randomises initial RAM contents.	2021-03-18 23:07:51 -04:00
Thomas Harte	622a8abf7f	Takes a stab at pixel output.	2021-03-18 22:57:10 -04:00
Thomas Harte	871bac6c8a	Marks out and approximately centres a pixel region.	2021-03-18 22:41:20 -04:00
Thomas Harte	fe3e8f87e7	Takes a shot at an all-border output.	2021-03-18 22:29:24 -04:00
Thomas Harte	87fc7c02e8	Provides a base pointer for video output.	2021-03-18 22:04:41 -04:00
Thomas Harte	f2620e6afb	Adds a CRT. Not yet clocked.	2021-03-18 21:54:42 -04:00
Thomas Harte	ab2ad70885	Takes a run at interrupts.	2021-03-18 21:29:52 -04:00
Thomas Harte	135134acfd	Adds a shell for video emulation.	2021-03-18 12:47:48 -04:00