eec20afe   
   From: Another1171@gmail.com   
      
   "Jim Leonard"  wrote in message   
   news:cd42bebe-349a-497f-b02c-9b1f3ba85390@a70g2000hsh.googlegroups.com...   
   > On Sep 8, 11:14 pm, Frank Durda IV   
   >  wrote:   
      
   >> The lack of DMA in base models caused grief for floppy disk controller   
   >> drivers, as those would normally use DMA channel #2. This   
   >> caused performance to be poor when floppy I/O was in progress,   
   >> and could cause stutter or silence in audio output.   
   >   
   > Are you saying that some Tandy 1000 models did not have DMA?  If so,   
   > that is news to me; I was under the impression all Tandy 1000s had   
   > DMA.   
      
   No. The DMA chip was on the plug in memory card (IIRC).   
      
   >> Still, there were hardware incompatibilities that didn't get resolved   
   >> for quite a while, like no -5V power on the ISA slots in the   
   >> original models, only discovered after someone bought a network card   
   >> from Tandy that needed -5V power to function and stuck the card   
   >> in one of those "compatible" slots. That's why later 1000 models   
   >> have a -5V regulator taped to the motherboard. We also had to   
   >> have custom hard-drive-cards built that used a different interrupt   
   >> because of IRQ conflicts on the early 1000 models.   
   >   
   > Do you happen to remember what IRQ those boards used?   
      
   http://tech.groups.yahoo.com/group/Tandy1000/files/Tandy_1000_Hard_Drive.pdf   
      
   "Adding an aftermarket hard drive to a Tandy 1000"   
      
   The Tandy uses Interrupt 2, IBM used Interrupt 5.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)