Path: csiph.com!au2pb.net!feeder.erje.net!1.eu.feeder.erje.net!nntpspool01.opticnetworks.net!aioe.org!.POSTED!not-for-mail From: David Hume Newsgroups: alt.folklore.computers Subject: Re: the FORTH computer language Date: Wed, 28 Oct 2015 22:04:00 +0000 Organization: Haphazard Lines: 22 Message-ID: <844mhamyzz.fsf@example.com> References: <84a8r92ptx.fsf@example.com> <84a8r92ptx.fsf@example.com> <84a8r92ptx.fsf@example.com> <11ba64cd-50b8-4778-9c06-97e204309109@googlegroups.com> NNTP-Posting-Host: 3NtQH5oMwdXa1l1iAsMESg.user.speranza.aioe.org Mime-Version: 1.0 Content-Type: text/plain X-Complaints-To: abuse@aioe.org User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.3 (gnu/linux) X-No-Archive: Yes X-Notice: Filtered by postfilter v. 0.8.2 Cancel-Lock: sha1:nHq5nGkxID9Y5xe0+j36OjDjdJA= Xref: csiph.com alt.folklore.computers:153490 Michael Black writes: > The 6502 had a bug. Maybe not a bug, but an early release was missing > one of the shift register capabilities, so the manual said to shift > the other way using the op-code that did work. I think it was that > the opcode was missing, rather than implemented wrong. A later > release did fix it. > > The 6502 also had a bug, I can't remember if it was fixed when the > CMOS version came along. The 6502 used a single page for the stack > and the right combination of op-codes and address caused a problem, > the exact details I can't remember. That one was simply lived with, > someone found the bug, but it was a fairly esoteric combination that > caused it. > Wasn't there a bug whereby if you tried to load from an address ending in FF it would load the high byte from the wrong place? i.e. 00 on the same page. Anyway I think it was fixed in a later, maybe 6502C.