The defendant Stephen Favorito was employed by an attorney as a legal assistant. A jury found that he had forged his employer’s signature on seven checks and convicted him of forgery, uttering forged instruments knowing the same to be forged, and larceny. In his appeal he presents two questions relating to the exclusion of evidence. Neither claim has any merit.

1. At the trial, after his former employer testified that the defendant had made bank deposits for him, defense counsel asked the employer whether he had testified in a *139previous probation revocation proceeding. The lawyer acknowledged that he had but said that he could not recall whether he had been asked whether the defendant had made deposits on his (the lawyer’s) behalf. He testified, “If they asked me, I would have told them the same as I’m telling you.” After a bench conference, the judge stated for the record that defense counsel wanted to introduce in evidence a typewritten notebook, not an official record, which counsel represented contained transcripts of tapes made in a District Court, and that the book was offered on the question of the employer’s credibility concerning whether the defendant had made bank deposits.

There was no error in excluding the notebook. Apart from the question of the notebook’s authentication as a transcript of the defendant’s probation revocation hearing (see Attorney General v. Ware, 328 Mass. 18, 22-23 [1951]; Leach & Liacos, Massachusetts Evidence 265-271 [4th ed. 1967]), the matter of deposits was not a material issue in the case and “[e]xtrinsic evidence on a collateral matter may be introduced at trial for the purposes of impeachment only in the discretion of the judge.” Commonwealth v. Chase, 372 Mass. 736, 747 (1977). Moreover, only those portions of the transcript which might have contained inconsistent statements would have been admissible, and the defendant failed to separate those portions. Cf. Chase v. Chase, 271 Mass. 485, 490 (1930), and compare the procedure followed in Wheeler v. Howes, 337 Mass. 425, 427 (1958). There was no abuse of discretion or other error in refusing to admit the entire notebook. See Commonwealth v. Makarewicz, 333 Mass. 575, 593 (1956). See also Commonwealth v. Watson, 377 Mass. 814, 824-834 (1979).

The defendant also claims that cassettes of the probation revocation proceedings should have been admitted in evidence. The record, however, does not indicate that these were ever offered by the defendant and, in any event, the cassettes would have placed before the jury the entire transcript, which we have held to have been properly excluded by the judge. The cassettes would stand on no firmer *140ground than the notebook as a whole. See Commonwealth v. Watson, supra at 834-836.

2. The defendant also claims error in the refusal of the judge to permit a witness to testify to questionable behavior by the employer.1 There was no error in excluding the proffered testimony. Evidence of bad character for purposes of impeachment can only be shown by evidence of general reputation for veracity and not by proof of specific acts. Davidson v. Massachusetts Cas. Ins. Co., 325 Mass. 115, 123 (1949). See Commonwealth v. Binkiewicz, 342 Mass. 740, 754-755 (1961); Commonwealth v. Sperrazza, 379 Mass. 166, 169 (1979); Leach & Liacos, supra at 121-123. There was no claim that the witness could testify of her personal knowledge of the employer’s general reputation for veracity in the community. The testimony sought to be introduced was inadmissible. Commonwealth v. Baxter, 267 Mass. 591, 592 (1929).

Judgments affirmed.