[from EUUGN Vol.3 No.2] Compatibility Quiz Mike O'Carroll Microsystems Unit, Dept. of Electrical Engineering The University, Leeds LS2 9JT, England Herewith a super new quiz for all you 'DEC compatible' fans! Answers, on a postcard please, to the appropriate manufacturer. (N.B. to help those of you who have never gone to another supplier, our answers are included below.) QUESTIONS --------- Q1. What do you understand by the term 'DEC compatible'? Q2. What do you understand by the phrase '100%'? Q3 '[The controller gives] an emulation of all functional features of the DEC RJM02 subsystem'. Explain. Q5. 'Fully supported in this country!' [my exclamation rmark]. What is being supported here? Q6. Are DEC 100% compatible? Think about it. ANSWERS ------- A1. Certain features, such as the code number of the product, general register layout, etc. are not totally dissimilar from those encountered in the DEC version. A2. Pick a number in the range from 0% - 90%. We award 90% to our current Emulex controllers which can do most things in a reasonably compatible manner (apart from minor things like multi-sector transfers). Dilog get a slightly lower mark for managing multi-sector transfers, but locking up completely if anything else tries an NPR at the sane time. DSD do slightly better now, having fixed the problem whereby the extended address counter went 00, 10, 01, 11, in 'ascending' order. Xylogics got 5% for an LSI-11 controller which managed to execute the bootstrap, but fell over as soon as it tried to write anything. A Spectralogics controller got 1% as it managed to read in the bootstrap, but failed to execute it. [If you find the last two hard to believe, ask the engineers who came to 'get it working in 10 minutes, squire'.] A3. '... the maintenance mode features of the DEC RM02 controller is [sic] only partially emulated' - from the same manual as question. Presumably, 'maintenance mode' features are not 'functional' features. See also earlier correspondence in this august publication. A4. 'The diagnostics marked with an asterisk require certain patches'. See question. A5. The manufacture of telephone answering machines. A6. I've given enough away already. Work this one out for yourself. In order to stave off possible legal action, the author would like to point out that these comments (naturally) relate to our personal experiences with products made by the companies named. However, the points raised above have never been answered by those concerned (see question on support), so here's your chance folks! Incidentally, talking of legal action, here is a supplementary question: Q7. What, if anything, does the Trades Description Act have to say about terms like 'compatible'?