Where to find Hewlett Packard Historical Unadjusted Stock Prices

Hello, I acquired some old Hewlett Packard (it is HP Inc now) stocks in 1979 and 1980 and I am trying to determine the cost basis of these stocks.  I no longer have the records of what I paid for these stocks, and over time, the stock split 2-1 five times, and HP also spun-off of some of its divisions to new companies.  When I googled web sites such as HP Inc, Yahoo Finance, WSJ, Schwab, Merrill, NASDAQ, and the HP Inc stock administrator, they all show adjusted prices.  Is there a web site or some way that I can find the historical unadjusted prices back in 1979 and 1980, or calculate the unadjusted prices?  Thank you.