10 Apr
2024
10 Apr
'24
5 p.m.
I thought you could get regular channels as an optional feature?
<pre>--Carey</pre>
... The model 44 had no channels, there was
only direct I/O (a set of 32-bit parallel input and output registers) and a pair of
cartridge hard drives inside the CPU cabinet. Think DEC RK05s.
No channels? That doesn't sound right. The 360/44 I used certain had an RK05-like
drive in the CPU cabinet (I only remember one, though). I'm fairly sure it was a
16-sector pack, so more like an RK08. But the system ran both OS/360 and TSO, and had
three 2311 disk drives, three tape drives (with an amazingly ugly mechanical design), a
card reader/punch, and a line printer. Also some sort of terminal max, but I never used
the timesharing feature so I don't know what that involved.
It certainly had enough of a channel-like I/O system that the emulator program loader
could be implemented in a card reader channel program no different from that of other
360s. I remember quite well deciphering it using the CCW documentation on the "green
card".
Yes, the emulation of SS instructions was via traps, but specifically by a trap into
emulator mode in a separate chunk of memory not visible to the main OS.
I never saw the cartridge drive in use by anyone.
paul
On 04/10/2024 11:47 AM CDT Paul Koning via cctalk
<cctalk(a)classiccmp.org> wrote:
> On Apr 10, 2024, at 11:25 AM, Jon Elson via cctalk <cctalk(a)classiccmp.org>
wrote:
>
...