Bottom of the barrel. Can be had from aliexpress for less than $10.
Specs are a bit lacking:
- Product model: TJ-56-646
- PCB size: 57*34mm
- Working voltage: 4-5V
- MCU: STC8A8K64S4A12
- Display: 0.96 inch OLED display – 7P, 128*64 resolution
- Number of channels: single channel
- Sec/div: 500ms, 200ms, 100ms, 50ms, 20ms, 10ms, 5ms, 2ms, 1ms, 500us, 200us, 100us (100us is only available in auto trigger mode)
- Voltage range: 0-30V
- Sampling level: 10kHz@100us/div
- Trigger level: trigger voltage level.
- Trigger slope: ↑-rising edge, ↓-falling edge trigger
- Trigger mode: A-automatic mode, N-normal mode, S-single mode.
According to the datasheet: "The speed of ADC can be up to 800Ks."
A bit more info here:
https://zeusdiy.com/product/tj-56-646-mini-dos-lcd-oscilloscope-diy-kit/https://en.56dz.com/p/23.html