Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!batcomputer!cornell!uw-beaver!zephyr.ens.tek.com!tektronix!percy!cryo!billc From: billc@cryo.UUCP (William J. Coldwell) Newsgroups: comp.sys.amiga.hardware Subject: Re: 14 Mhz Hack Message-ID: Date: 14 May 91 10:46:30 GMT References: <1991May10.104421.22314@rulway.LeidenUniv.nl> <1991May13.081500.7980@rulway.LeidenUniv.nl> Organization: Cryogenic Software Lines: 61 In article <1991May13.081500.7980@rulway.LeidenUniv.nl> breemen@rulcvx.LeidenUniv.nl (E. van Breemen) writes: >In article billc@cryo.UUCP (William J. Coldwell) writes: > >>Not as easy as it looks, eh? Seems that CMI had the right idea after all, >>and even had an FPU plus a software toggle. PA's only have 8 chips and >>could access most ROMs at 14MHz. > >They have probably used PALS for reducing the number of chips and protecting >their board against copying. Yes, but board space and noise considerations are also in there. Then there is the infamous "it works in this machine, but not that one..." and the "Oh [insert your own favorite profane statement here], Commodore has just released _another_ rev motherboard that moves the [part] to a new location, causing an increased cost of a [different part]. It also breaks [other manufacturer's item] when doing [CPU or DMA action]. This in-turn causes a rush to the [name] board layout package for the changes necessary to make the [your product] work with the latest rev, reducing the meager profit margin." ;-) >>>Currently I am converting the board into a SMD version, which will be >>>published. >>[stuff deleted] >>Why? Seems to me that there is too much competition with resale PAs >>dropping in price, and ICD's being a hair more than new PAs. 14MHz >>68Ks were a great thing 3 years ago, but with 020's and 030 prices >>dropping like flies it makes more sense to do a Lucas/Francis type >>accelerator for the 500 (IMHO). > >This is true, but the 14 Mhz hack will provide the needed experience to >build a reliable 68020/68030 board. The Lucas/Francis boards are >not reliable. You have to experiment with LS/F logic to make things >work. And I don't know how the boards will perform in a heavy DMA >enviroment. The 14MHz hack will only give you a limited experience on how to deal with a syncronous CPU, while the Lucas/Francis was an async accelerator. It's reliability was about what is expected on the board of that size in a noisy A1000 running at that speed ;-). >>Speaking from my experience, the accelerated 68K market is d.e.a.d. > >Commercially spoken yes, but for people who don't have enought money, >say $500, it can be interesting. <$500 will still get a nice speedup. You can get a 25MHz Mega Midget Racer (030) for about that price. >Erwin. > >PS. I have received several requests for publishing the board. I have >already said before, that I will publish it when it is ready in a SMD >print version (2 or 3 months). SMD to me, no longer denotes a "hack". ;-) -- William J. Coldwell PLink: CRYO I'm a 3-DPro, wouldn't you Amiga Attitude Adjuster BIX: wjcoldwell like to be a 3-DPro2 ? Cryogenic Software UUCP:billc@cryo 3-D PROFESSIONAL 2.0 #define STD_DSCLMR "The above opinions are mine. You can't have them."