Newsgroups: comp.sys.cbm Path: utzoo!utgpu!watserv1!maytag!xenitec!geoffw From: geoffw@xenitec.on.ca (Geoffrey Welsh) Subject: Re: terminal progs? Reply-To: root@zswamp.fidonet.org (Geoffrey Welsh) Organization: XeniTec Consulting Services, Kitchener, ON, Canada Date: Wed, 19 Sep 90 23:09:45 GMT Message-ID: <1990Sep19.230945.26660@xenitec.on.ca> References: In article dg@pallio.UUCP (David Goodenough) writes: >After having seen the Z80 code in their CP/M BIOS, I'd have to agree >with that. I'm a CP/M / Z80 programmer rather than 6510 / 8502, so that >opinion is based on the CP/M code. Suffice it to say they have a CPU >clocked at something like 6 MHz, but it gets a throughput of about 2 MHz. >I.e. they are wasting 65% of the CPU's horsepower in badly written >interrupt and screen I/O drivers. Actually, the Z80 is clocked at 4 MHz, but runs two cycles on/ two cycles off to accomodate the VIC chip's DMA. That is where it gets its 'effective' 2 MHz speed. UUCP: watmath!xenitec!zswamp!root | 602-66 Mooregate Crescent Internet: root@zswamp.fidonet.org | Kitchener, Ontario FidoNet: SYSOP, 1:221/171 | N2M 5E6 CANADA Data: (519) 742-8939 | (519) 741-9553 My comments do not represent and should not obligate anyone but myself.