s884764@otto.bf.rmit.OZ.AU (Grant Waldram [Atom Smash]) (12/10/90)
Well, first posting, and it's a suggestion, not a problem... Hopefully that's a good sign, for me anyway. No, my PC532 isn't up and running yet, though I'm roughly 30% of the way through the soldering. Just waiting on a few parts to arrive from Steve. Anyway, back to the point... I've noticed a few people commenting that they don't feel confident working with SCSI, and would like to have a more conventional bus to work from. Personally, I'm happy with the SCSI approach, as it does provide a nice comforting hardware barrier between the card most of the board. Or at least it appears to. Shoot me down if I'm wrong. So, it seems it would be reasonable for someone who has a) the time, and b) the expertise etc.. (the former seems to be a rare commodity around here :) to come up with a design which incorporates some basic circuity to at least ease the interfacing to SCSI. Perhaps a DP8490 and a bit of DRAM (or maybe SRAM since, as someone already pointed out, it is becoming comparatively cheap?) just to get the nasties out of the way. A description of how do deal with it and what sort of behaviour to expect would finish it off nicely and might make some of the ideas that are floating around here easier to bring to fruition. -------------------------------------------------------------- Blame me for these ideas. I take full responsibility for them, but no responsibility for the consequences :-) Grant Waldram (Atom Smash) --- gtw%eyrie@labtam.oz.au or, if you're feeling lucky --- gtw@eyrie.img.uu.oz[.au?]
rhyde@ucrmath.ucr.edu (randy hyde) (12/11/90)
The only problem I have with working with SCSI is that you've got to design a whole 'nother computer system to do the interface. Considerably more work than adding a latch to obtain a parallel port. From the hardware point of view, SCSI is a lot more work. Even from the software point of view SCSI is a lot more work. From the Systems point of view, SCSI is probably the highest performance (when done right) because it distributes the processor load. As soon as my board is up, I'll be wanting a SCSI adapter for the PC so I can get mundane interfacing out of the way. I'd still like to hang some peripherals off the PC532 since it runs faster than the 12-Mhz 80286 I plan on connecting up. As an aside, do XTerminals always connect across Ethernet? Has anyone found one which talks to SCSI? I think an Xterminal on the PC532 would be kinda' nice. Has anyone else done this? Also, what's the current status of MINIX, GCC, GLD, GAS, and G++. Has anyone managed to get GCC running under MINIX (or, at least, producing MINIX executable files)? *** Randy Hyde O-)
cruff@ncar.ucar.edu (Craig Ruff) (12/11/90)
In article <10427@ucrmath.ucr.edu> rhyde@ucrmath.ucr.edu (randy hyde) writes: >The only problem I have with working with SCSI is >that you've got to design a whole 'nother computer >system to do the interface. Considerably more work >than adding a latch to obtain a parallel port. Well, maybe not. I read an article in Circuit Cellar, Ink (I think) recently that showed how one might get away with less. Basically, you fake enough of the interface so that all real SCSI devices know the bus is busy and stay off while you access your pseudo-SCSI device. Then, you could use the SCSI bus however you liked (within some restrictions). As long as BSY is asserted, you can use the other control lines to do things like register select, read/write, etc. I can check for the exact article and issue if anyone is interested in the details. -- Craig Ruff NCAR cruff@ncar.ucar.edu (303) 497-1211 P.O. Box 3000 Boulder, CO 80307
culberts@hplwbc.hpl.hp.com (Bruce Culbertson) (12/12/90)
> Also, what's the current status of MINIX, GCC, > GLD, GAS, and G++. Has anyone managed to > get GCC running under MINIX (or, at least, > producing MINIX executable files)? > *** Randy Hyde O-) Pc532 Minix is alive and well. I distribute it so send me e-mail for details. Included is a GCC binary which runs under Minix. Since I already had my own assembler and linker when GCC came along, I have not bothered to port GLD or GAS. Bruce Culbertson culberts@hplabs.hp.com