Some oddball items I occasionally put up.

Volume Levels for Optimal D/A Emulation on an AY-3-8912 Chip
A table containing optimally selected volume levels to achieve the most linear 8-bit D/A output possible from an AY chip. The table takes advantage of the logarithmic nature of the AY chip's output levels. Short text at the start of the file explains why emulating a 7-bit D/A is much better.

42 Column Print Utility
Andrew Owen's print utility for 42 column text from Basic. It sits just under the UDGs at address 65000 and will take over channel 3 (the printer channel). The routine can be called from m/c with a call to 65021 with the character to print in the A register. A small readme is included.

Video Display Timer
A utility for measuring video display timings on real Spectrum and Timex hardware. Follow on screen instructions and use CAPS and SYMSHIFT for faster changes.

Tommy Gun Editor
The latest version of the Tommy Gun editor can now be found at WOS under utilities.

Turns Spectrum Beeper into a DAC
A second attempt at using PWM techniques to turn the Spectrum's beeper into a DAC. This version uses a 16kHz carrier wave, allowing a signal bandwidth of 8kHz and an effective DAC resolution of 4.7 bits.

Z80 Timing Diagrams and Info on IM2 Interrupts
From Mostek's Z80 Data Manual (c) 1978.

Circuitry Supporting the IM2 Mode That Can Be Added To Z80 Peripherals
Untested schematic diagram for IM2 peripherals.

A Fast Breadth-First Pattern Flood Filler for the Sinclair Spectrum, TS2068 and Clones
Includes an article explaining how the program was developed.  Here are the programs listed in the article.

Dom's DStar, a Conversion of a TI-86 Calculator Game for the Spectrum
Includes Dom's original Z88DK C source.

A Collection of Small Test Programs Written in C Using Z88DK and the Sprite Pack Library for the Spectrum:

Callbacks
Flies
Test1
Pattern Flood Fill