XBR4DB26@DDATHD21.BITNET (OLAF THUN) (12/30/88)
Does anybody know how much "compatible" the Apollo AT-Compatible Bus in the DN3000 is? Can I use normal AT/PC-Compatible cards with this bus using normal PC-IRO and PC-DMA? Does anybody have experience with an AT/PC-Compatible Cardidge Tape Controller used with the Apollo AT-Compatible Bus? Thanks in advance Olaf Thun Technische Hochschule Darmstadt Institut fuer Elektrische Energieversorgung Schlossgraben 1 6100 Darmstadt West-Germany Bitnet: XBR4DB26@DDATHD21.Bitnet
gaz@apollo.COM (Gary Zaidenweber) (01/04/89)
From article <8812300656.AA02335@umix.cc.umich.edu>, by XBR4DB26@DDATHD21.BITNET (OLAF THUN): > Does anybody know how much "compatible" the Apollo AT-Compatible Bus > in the DN3000 is? > Can I use normal AT/PC-Compatible cards with this bus using normal > PC-IRO and PC-DMA? > Does anybody have experience with an AT/PC-Compatible Cardidge Tape > Controller used with the Apollo AT-Compatible Bus? > > Thanks in advance > > > > Olaf Thun > Technische Hochschule Darmstadt > Institut fuer Elektrische Energieversorgung > Schlossgraben 1 > 6100 Darmstadt > West-Germany > > Bitnet: XBR4DB26@DDATHD21.Bitnet The DN3000 ATbus is quite compatible and the DN3010 corrects a deficiency which was overlooked. We even implemented edge-triggered interrupts since that was what IBM chose (even though the interrupt controller can be programmed to be level-sensitive) and some manufacturers had specifically designed for edge-triggering. Many of our products are built upon standard, off-the-shelf AT-bus products. You may use PC-interrupts, however, some of the interrupt levels are reserved for Apollo-supplied devices. We supply a configuration worksheet in the documentation for the product which will enable you to find the appropriate available interrupt levels in your configuration. DMA is also possible but there is some difficulty since there is no IOMAP to translate between the AT bus and the system memory bus, therefore DMA must not cross a page boundary. There is a way, however, to stop and start DMA in the interrupt routine and do DMA which looks continuous to a calling routine. -- Gary Zaidenweber | "I have a higher and greater standard UUCP: umix!apollo!gaz | of principle [than George Washington]. ARPA: gaz@apollo.COM | Washington could not lie. I CAN lie AT&T: +1 508 256 6600 | but I won't." --Mark Twain