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TomHarte / CLK

A latency-hating emulator of: the Acorn Electron and Archimedes, Amstrad CPC, Apple II/II+/IIe and early Macintosh, Atari 2600 and ST, ColecoVision, Enterprise 64/128, Commodore Vic-20 and Amiga, MSX 1/2, Oric 1/Atmos, early PC compatibles, Sega Master System, Sinclair ZX80/81 and ZX Spectrum.
MIT License
931 stars 52 forks source link

Apple II flashing text flashes too slowly #1344

Closed ryandesign closed 7 months ago

ryandesign commented 7 months ago

Compare the appearance of running this BASIC program in Clock Signal:

FLASH:?"THIS IS FLASHING":NORMAL

with what you get in MAME, Virtual ][, or OpenEmulator.

ryandesign commented 7 months ago

In Sather's Understanding the Apple IIe, page 8-13, it says:

The FLASH signal toggles once for every 16 video scanner overflows (Figure 3.8), so FLASHING text switches back and forth at a 1.87 Hz rate (3.74 alternations per second).