jk@utastro.UUCP (John Krist) (02/08/86)
I thought that an update review of the DSI-32 board from Definicon Systems, Inc. might be of interest to those who are still looking into this product. I have found new things since my original review from December. But first.. ** DON'T FLAME ON ME !! I DON'T WANT TO HEAR IT !! HAVE A QUESTION? ASK !! FEEL LIKE INSULTING AND QUOTING SALES HANDOUTS? KEEP IT TO YOURSELF !! This is going to be a review, and I don't want to find my mailbox filled with blah, blah, blah about how this or that system or chip is better and that I am stupid, as has happened before. Whew! Ok, on to the fun stuff... Let's talk about compilers. There has been talk about accuracy of the compilers in this newsgroup before, so I won't say anything on that. The documentation doesn't include any references to compiler switches which are there. Some of these affect the results considerably. One (-x88) suppresses generation of slow and wasteful code to get around old FPU bugs. This speeds up the Fortran Whetstone by about 20%. Another (-x71) makes all Fortran calls for single precision variables be made in single precision (the default is to convert to double precision and back again. Is this teh UNIX default also?). All this gives a Whetstone time of 3.56 seconds (about 280k whetstones/sec). The Pascal compiler seems to have trouble with the field width specifier in the write statements. The following code, WRITELN ( 'h':6 ) produces "hhhhhh" instead of " h". I have had very little experience with the Pascal, so there could very well be more bugs. I have had not done much with the C compiler, and I have not found any bugs. The compilers and libraries have been updated about four times in the past three months. Updates are $15. It seems that much of the blame for whatever problems are in the compilers lies with Green Hills Software. They do not want to provide much information on the compilers (the Definicon people found the extra switches by searching through the source code) and do not even provide full reference manuals for the languages (I use the manual from my Digital Research F77, which, by the way, is the worst compilers imaginable). There are errors in both the manual and read.me files concerning the SVC interrupt calls to the MS-DOS shell. The read.me file is incorrect regarding the SVC 20 call (call IBM interrupts). The entry in the manual is correct. Interrupt calls ARE available through the _BDOS call from any of the languages. Also, there are calls available from any language to move memory to and from the IBM ram and DSI ram, input and output to a port, and make C library calls. I have the graphics package, which supports the IBM color graphics card and the Hercules graphics card (720x348). It is easy to set up the memory so that many frames can be generated and downloaded for animation purposes. The animation results are acceptable, and I get about 8-14 frames per second (very rough guess). The problem is that the downloading of the frame can be seen (those familiar with the way the Apple loads in a picture by BLOADing it know exactly how it looks, only it happens fast but perceptibly). I suppose, though, that things would be better on an AT, since I have the regular PC, and the memory fetching would be faster. The really big problem is the time it takes to generate the pixel in memory. With the source code (in C) included, one can see that for every pixel, the following is used : temp = 0x2000 * (row % 4) + 90 * (row / 4) + (col / 8) Ugh! Ack! This takes FOREVER! I'm trying to find a better way, but I'm not too hot on pixel mapping and such. If someone out there knows the secret, HELP! Of course, with the way the card works, you can't have cursors. Let's talk about support. First word of advice; don't try calling them except between 2 pm and 3 pm California time (the fact that they're in California readily explains this). They don't seem to hang around long, but when you get them, they know what they are talking about. The bad thing is that they keep really quiet about updates, bugs, etc. If you're lucky, they will send you updates from out of the blue and ask for $15. Don't pay the money and they won`t send you any more updates. Don't expect to get bug reports, and if you can get on the semi-support BBS (I tried an hour each day for a week to no avail) then the bug reports you will find are the ones the customers have entered on the BBS. This is the weakest point of the entire DSI-32 board. If you want information, you have to call, wait 10 minutes for someone to find the right person, and then find out that you were not sent the already-a-month-old update. Don't write (it took 6 weeks to get a reply by writing). In all, I still think this is a great board, and the compilers are superior to the ones for the PC. The only big problem is the lack of bug reports, and this is something that Definicon should take seriously. John Krist U. Texas Astronomy Dept. jk@utastro.UUCP {allegra,ihnp4}!{noao,ut-sally}!utastro!jk