Can 's be used to mean was? [duplicate]
Solution 1:
There is no natural/common abbreviation of "I was".
A person speaking with extreme slang, and an affected accent, might say "I's garn down town when I saw dis babe", but usage would be rare.
Solution 2:
"I's" as a contraction of 'I was' is nonstandard and dialectal but nevertheless widely spoken and heard in my neck of the woods (West Country, England). For example,
"I's living in Salisbury before I moved here".