Difference between revisions of "Talk:KS10"

From Computer History Wiki
Jump to: navigation, search
(Second Unibus also 18-bit?)
 
(Second UBA also 18-bit?: No, 16-bit only because everything on it was 16-bit only)
 
Line 2: Line 2:
  
 
I'm trying to figure out whether the "second" (i.e. not disk) Unibus was also operated in 18-bit mode.  I have a vague recollection that only the disk controller needed 18-bit data transfers, but I can't confirm this.  I read the technical manual, but it doesn't seem to indicate any difference between the two. [[User:Larsbrinkhoff|Larsbrinkhoff]] ([[User talk:Larsbrinkhoff|talk]]) 10:58, 6 February 2025 (CET)
 
I'm trying to figure out whether the "second" (i.e. not disk) Unibus was also operated in 18-bit mode.  I have a vague recollection that only the disk controller needed 18-bit data transfers, but I can't confirm this.  I read the technical manual, but it doesn't seem to indicate any difference between the two. [[User:Larsbrinkhoff|Larsbrinkhoff]] ([[User talk:Larsbrinkhoff|talk]]) 10:58, 6 February 2025 (CET)
 +
 +
: I haven't checked the documentation/code, but my strong recollection is that the second UNIBUS is operated in 16-bit mode only. For one thing, very few UNIBUS devices can operate in [[UNIBUS parity#18-bit width|18-bit mode]] - the only ones I know of are the [[RH11 MASSBUS controller]] and the [[RK11 disk controller#RK11-E|RK11-E]]. (Note that the RH11 also needs MASSBUS devices that can operate in 18-bit mode, to operate in 18-bit mode; the [[TM02 magtape controller]] apparently did not have that capability, because the drives that could connect to it only operated in 8-bit mode - again, I have not checked the prints to be certain.) Which would explain why the TM02 and its RH11 are connected to the second UNIBUS. Everything else on that bus was a 16-bit device. [[User:Jnc|Jnc]] ([[User talk:Jnc|talk]]) 15:42, 6 February 2025 (CET)

Latest revision as of 15:42, 6 February 2025

Second UBA also 18-bit?

I'm trying to figure out whether the "second" (i.e. not disk) Unibus was also operated in 18-bit mode. I have a vague recollection that only the disk controller needed 18-bit data transfers, but I can't confirm this. I read the technical manual, but it doesn't seem to indicate any difference between the two. Larsbrinkhoff (talk) 10:58, 6 February 2025 (CET)

I haven't checked the documentation/code, but my strong recollection is that the second UNIBUS is operated in 16-bit mode only. For one thing, very few UNIBUS devices can operate in 18-bit mode - the only ones I know of are the RH11 MASSBUS controller and the RK11-E. (Note that the RH11 also needs MASSBUS devices that can operate in 18-bit mode, to operate in 18-bit mode; the TM02 magtape controller apparently did not have that capability, because the drives that could connect to it only operated in 8-bit mode - again, I have not checked the prints to be certain.) Which would explain why the TM02 and its RH11 are connected to the second UNIBUS. Everything else on that bus was a 16-bit device. Jnc (talk) 15:42, 6 February 2025 (CET)