CK-8045ABM. Curtis Keyer Chip, thru-hole 28 pin.

The legendary Curtis keyer chip is now the revolutionaryCurtis 8045ABM with more features than ever at no extra cost!
Features include: Built-in 89 character memory, expandable non-volatile memory, true sine wave sidetone with soft rise/fall times eliminate harsh keyclicks for beautiful sounding sidetone.
You also get type A or B iambic keying, dot-dash memory, adjustable weight, tone and speed, automatic or semi-auto mode, low current drain ... choose... 28 pin.

Specifications:

Supply Voltage: 4 Vdc min., 6 Vdc max. (5 Vdc recommended),
Operating Current: Depends on sidetone and keying arrangement,
Speed Range Approximately 5 to 65 WPM,
Iambic Operation: A or B iambic. Automatic or semi-automatic,
Weight Control: Weight can be added or subtracted,
Dot-Dash-Space Ratio: 1:3:1 standard,
Sidetone Generator: Internal using external low-pass filter -- about 300 to 1200 Hz,
Message Memory: 85-character built-in volatile or 507-character external non-volatile,
Key Debouncing: Internal logic,
Package: 28-pin SDIP (SOIC package available)
,