Hello,
I'm working on including more sound into my 'LISY80' (www.lisy.dev) by experimenting with a system80B soundcard of a #Victory
Because Gottlieb spend only 5 wires to control the sound I was under the imagination that the maximum number of sounds
for a system80 Gottlieb is 32. However by playing all the 32 sounds manually (by let LISY sending the codes to the soundboard)
I did not hear these 'Checkpoint one', 'Checkpoint two', .. speeches.

By incident I figured out that Gottlieb did implement an 'extended sound set' which is controlled by soundnumber 0x1D (29 decimal)
When I send soundnumber 0x1D no sound is played, but it has an impact of the sound playing after that sound.

For example if I send sound 0x1E (28 decimal) there is an engine noise, but if I send two codes 0x1D AND 0x1E it says 'Checkpoint one',
same for the combination 0x1D AND 0x1C ( Checkpoint two). So obviously Gottlieb extended the soundnumbers on Victory Soundboard
by introducing this 'control code' 0x1D.

Before I try to figure out more by doing more experiments I wanted to ask if anyone have more information on this feature?
Is it used for all system80B soundboards, are there other 'control codes' introducing a possible 'third sound set'?

thanks for your help
Ralf